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Q1:- TEMPERATURE
The effects of temperature, animals and plant are distributed to different environment
regions as per their adaptive features. Plants like cacti, thorn bush, coarse grass, and
desert-rose collectively known as xerophytes live in very high temperature and prolonged
drought periods (in the desert or semi-desert) Such features have enabled organisms in
the particular high temperature regions to survive there and not others.
Arctic, extreme North of Alaska. Canada, Russia, Tundra are examples of regions in the
world with very low temperatures which can reach up to-24degrees centigrade Plants
/vegetation which survive in the cold regions (Tundra) have enzymes and hormones
which are active at low temperatures. Have slow growth, high degree of to tolerance cold.
There are few species of plants than in any other biome, have small life cycle to complete
their growth (50-60)days. Most are small plants. Example lichen, mosses sedges,
bearberry. There is low ground cover/ vegetation.
Similarly as lakes become shallower sun is more able to reach the bottom than I deep
lakes which in turn increases water temperatures and plant growth. Increased productivity
for photosynthesis causes even more nutrients accumulate at the bottom which causes
other organism to live there.
Many plants and animals live in regions of moderate temperature between 10C which is
minimum for the effective photosynthesis and 35C. Average temperature for most plants
is 25 degree centigrade. This range of temperature can vary. Animals are in two groups
according to their ability to regulate body temperature, poikilotherms ; those whose body
temperature various as the environmental change. These include reptiles and amphibians.
They hibernate when condition is unfavorable. The second group is homoitherms whose
body temperature is constant with respect to temperature change in the external. Birds
and mammals make this group.
MOISTURES/ RAINFALL
Moisture refers to the presence of water in the earth which determine the type of
vegetation and distribution of species. Water is the vital compound on the world which
covers 2/3 of the world. Almost every living things needs water for life. Absences of
water would affect/upset the metabolic activities in living things eventually would have
disappeared/ perished. Water is used for photosynthesis (plants),providing shapes of
different parts of living things, transporting materials in the body, respiration,
reproduction purposes and many other functions.
Some plants require much water; other moderate and some need little water for their
survival depending on the adaptive features available in a particular plants species hence
this distinguish the environment/ home of different species in the universe.
Plants which survive in areas with prolonged draught/low moisture like in the deserts are
known as xerophytes. Have some adaptive features which enable them capable of
surviving in their habitats by reducing the rate of transpiration such as having needle like
leaf, few/no leaf, have spine to defend from being eaten by animals, have sunken stomata
to reduce evaporation, have thick waxy cuticle in their leaves. Examples, cactus, and
desert rose plant species.
The second group of plants includes hydrophytes, which survive in fresh water or
permanently water logged soil, Example marshes, and rice pad. Other plant species are
those which live in salts water (marine plants) such as in saline semi desert, mangrove
swamps, marshes and sloughs. Such plants are known as halophytes. For example is the
salt marsh grass sparting alteniflora they can tolerate wave actions, salts, and tides
because of their adaptation factors. Neophytes are found in areas with normal amount of
moisture (rainfall) they can withstand neither wet nor dry conditions. That is they survive
in area with moderate
moisture and temperature. They lack adaptive features as those
of xerophytes. Example maize, lilac, cloves. These are the most abundant plant species in
the environment.
WIND
Wind is air in motion from high pressure region to low pressure areas. Wind can modify
can modify climate of some regions hence favors life of some plant species in the
direction of winds (wind ward directions) while the leeward side receives dry air which in
turn hinder better survival of plants. For example in the Mediterranean region, the jet
streams move southwards allowing the westlies winds blow from the sea to bring
moisture during dry summer and allowing the westerlies winds blow from the sea to
bring moisture during dry summer and enable well grow of citrus fruits. The temperature
of the Mediterranean rise high up to 40degrees centigrade due to the local winds (sirocco,
khamis) from the Sahara desert which kill many plant species. In the equatorial region,
trade winds which converge at the equator (Inter tropical Convergence zone) force warm,
moist and unstable air to rise up which results into the heavy rainfall in the area. The
winds also speed up the rate of evaporation and transpiration from trees and valleys
which also facilitate the process of rainfall formations. All this enable well survival of
plants and even animals. Other areas in which wind winds affect the climate include
India, China; Pakistan in Asia where the monsoon winds over the Indian Ocean brinds
warm, moist unstable air and conducive rainfall to the coastal area of Asia for plant and
animal species survival.
LIGHT INTENSITY
Light is the main sources of solar energy which is needed by plants to manufacture their
food. Nelson (1986) explains that light helps plants synthesize food, opening of stomata,
phototropic movement, stem and roots elongation. The amount and duration of light on
plants affect plants, hence causes some plants to be found in different areas from others.
Consider the seaweeds, cannot trap light energy directly from sun rays instead filter it off
from water. So see weeds are found in /on see where they can trap the solar energy in
wave form from the water and reduce its intensity. Example small red algae need very
little light and can occur under large algae. The amount of light decreases towards the
floor of the tropical rainforest, and decrease in the ocean depths. This features favors
species which can to live in dim light to survive under the shed of tall trees only like the
oak. Some plants need high light intensity for their photosynthesis process, hence grow
very tall in order to trap light. Example oak, Cyprus and pine trees in the rainforest. For
this case these plants cannot survive in the cold regions like in the northern America,
Tundra as they will lack enough light intensity. Big trees like oak, Cyprus, pone are used
to produce timber thus will attract people and even encourage the establishment of
sawmills for lumbering.
SALINITY
Saline soil is the soil which contains dissolved substance known as salts for example
chlorides, sulphates; bicarbonate of calcium, sodium. Ocean water is saline as it contains
dissolved substance (salt). In oceans salinity, increases when run off from the farms
especially where more fertilizers are applicable is probed into the ocean and when
potential evaporation occurs, the water becomes more salty. More vapor-transpiration
than precipitation in dry region also increases salinity on the soil because there’s no water
to leach the soil down instantly, more water is evaporated and leaves the salty on the soil.
Example in mountain, California, the soil is more saline. More salt on soil draw water
from the plant body and result into plant wilting and leave some patches on the land.
Salts surround plants roots, hence unable to absorb water from the soil. Saline salt also
lack many microorganisms.
Salinity becomes a problems when enough salts accumulate in the root zone to negatively
affect plant growth. Excess in the root zone hinder plants root from withdrawing water
from the surrounding soil, hence cover amount of water available in the plants regardless
of the large amount of water available in the soil. Salt in the water causes plant to exert
more energy salinity is dependant on the soil type climate and Irrigation. Most plant line
in areas saline which doesn’t interfere the osmosis. There are plants which are adapted
for concentrated environment Example; zooplankton and phytoplankton are found in
marine environments because of the adaptation.
These are animals which are adapted to marine environment since they have features like
use small energy to regulate then body fluids. Have glands for secret salts to reduce body
salts. Other marine obtain water from food they eat hence avoid ocean water. Examples
of marine animals are turtles, crocodile, marine reptiles (Iguanas), and sea snakes.
REPRODICITY
Refers periodism as the condition where some organisms can undergo certain process
like flowering, germination, photosynthesis at specific times. Photoperiodic means the
influence of the relative length of day and night on the activities of organisms. Flowering
and many other responses in both animals and plants are regulated by day length. Some
plants require long days for the flowering processes named as long day plants, For
example spinach, lettuce and petunias, Such plants undergo early flowering in day
treatment and can’t tolerate certain maximum period of dark each day. They inhabit
areas of long days with high temperature like in desert where they produce much during
summer period. The short day plants is the second group of photoperiodic plants require
short days for flowering that is only when light period is short are known as the shorter
day plants. They need flash of light in the night for the process flowering. Example
poinsettias, cocklebur produce much during winter season most common in Polar
Regions. The third group of plants is the day-neutral plants which live commonly in the
equator, where day and night are equal. Flowering process is the same on the day and
night most plants are on this group. Example tomatoes and maize.
ROCK AND SOIL
The type of rocks will determine the type of soil found in particular region and ultimately
the type of plants/ animals inhabiting the area. Some rocks are very hard (for example
Igneous like quarts) which are only affected by physical (Mechanical Weathering) to
form large particles of soil which includes sand, silt with the following properties.
Good drainage, few nutrients, coarse texture, fewer but much larger pores which water to
pass through quickly (fast infiltration) hence low water loge. Have large soil size
/particles thus the soil is highly leached that is nutrients go deeper during moisture or
irrigation purpose. They lack microorganism to decompose decayed organic matter.
All these factors render difficult survival of micro organism and some plants especially
those which need more water, humus for survival. Plants which survive in soil sand and
include account, cashew nuts, groundnuts which have adaptive features for surviving in
areas with little nutrients and high drainage. Such feature include, have roots which can
penetrate coarse soil (large particles soil, have tap (very long root), have small leaves to
reduce transpiration. Other plants like carrot can survive in light sand soil, Example In
coast region Mtwara. Others plants like banana, coffee, and maize require fine soils, with
normal drainage; nutrients, good soil aeration and more moisture cannot survive in areas
with sand soil unless the soil is improved by the addition of manures/fertilizer.
The softer rocks like the (mica feldspar) are mostly affected by weathering to form clay
soil which is characterized by having finer texture, poor drainage, and more nutriens.
This type soil allow only some plants like rice pads, yams, to survive here since the soil
has high water retention to water (water lodge), few pores, very compact in structure.
Plants living in water logged areas posses some adaptive features such as having high
transpiration rate.
Soil
Each type of soil has different properties from the other among the following textures,
aeration, presence of microorganism, soil temperature, presence of minerals (nutrients)
acidity (PH), soil water, free from salt
Structure/soil profile.
The type of soil in a particular area depends in the climate of there, biological processes
environment the parent rocks, physical and chemical processes and will determine the
type, number of animals and plants surviving there. Most plants and animals species
occupy the upper horizon of the is well aerated, has many pores receive good moisture,
and microorganisms are many which produce manures. The second horizon from top soil
decreases in quality while the third horizon is much poor since is the close to the parent
rock with large soil particles.
soil ph
It is a measure of degree of concentration of the hydrogen ions in the soil. If the soil
contain more hydrogen ions is said to be more acidic. Soil ph is measured by ph scale.
The soil is neutral when the ph scale read 7. Heavier rainfall, and irrigation causes soil
acidic as it leaches element such as calcium, sodium faster than they can be replaced by
weathering, and replaced by the hydrogen ions. Acidic soil makes organic matter more
soluble and hence vulnerable to leaching and makes the soil infertile. It discourage
microorganisms as no organic material to decompose, hence the soil becomes infertile
and no good survival of plants. Example; In upland Britain these are more acidic soils
due to heavier rainfall, slightly acidic soil is the optimum for farming in Britain. In areas
like American praises there is neutral acidic, due to balanced rate of rainfall and vaportranspiration
ALTITUDE
This is the height above sea level. Moving away from the sea height increases, this means
that the height in the mountain is higher than that of the sea, and temperature decreases as
the height increases. As increase in altitude there’s decrease of number of species, height
of plants, density of plants, and growth rate of plants, growing season and biomes. For
example near the peak of Mount Kilimanjaro between 400m and 500m above sea level
there are very few and small plants like mosses, lichens, bearberry which grow in
patches, while in the lower areas (0-100m) above the sea level there are dense and big
plants like oak, flower grasses, brambles.
SLOPE/GRADIENT
This is the angle of the earth’s surface. Some areas have steep slopes while others have
gentle slope. In the steep slop areas there is high velocity of water, poor percolation of
water, more soil erosion, few/no soil nutrients, and lack microorganisms. All this factors
make the soil less productive as plant species can no grow well which in turn hinder
human being survival. In the high steep areas also people cannot live because it is
difficult for construction, transportation. On the other hand in the areas with gentle slope
many plant and animal species can survive because of good percolation of water, more
humus, ore micro organisms, thick soil and flatness of the area which permit easier
constructions and transportations.
ASPECT
In the uplifted areas like mountains, hill and tall buildings tend to block the sunrays and
moist air from reaching into the opposite sides of that features or objects. This also
affects the distribution of plant and animal species. The side which faces the sun will be
illuminated with sun rays hence plants can undergo photosynthesis to manufacture their
food hence well distributed and will favor the survival of micro organisms and animals
which depend on plants for their survival. On the leeward side of the mountain is dry
because the blowing moist air is trapped on the wind ward side of the mountain hence
more plant/animal species on the wind mount Kilimanjaro is very dry and few people
leave there.
FIRE
The diversity of fir e and its effects on the ecosystem depend largely upon the climatic
conditions. The fire is likely to be hottest in dry weather and in the northern hemisphere
on sunny and the south facing slopes where the vegetation is driest. The spread of fire is
fastest when the wind is strong and blowing uphill and where a build-up of combustible
materials. Vegetation also determines the extent of destruction, for example un grassed
grasslands and especially the savannas with little biomes but a thick little layer and in the
conifers forest where the leaf litter burns readily fire kill many plants and animals species
when it erupt thus leave the area desert. An example of fire that has destroyed many
plants species and human hatatis is that of South East Australia in (1994-2000). Fires in
the forest and other can occur naturally because of friction of trees, Vulcanicity, and
earthquake. Human being are the most source of fires in the ecosystem from their
activities like honey harvesting, bomb blast, cigarette smoking.
Despite the impact of fire to many plant/animal species there are other plant species
which require fire for their distribution for example the acacia seed need fire to
germinate.
Q2: INTRODUCTION
Species is a class of things subordinate to a genus and containing individuals sharing an
attribute or attributes absent from other member of the genus and called by a common
name; the second of the five predictable.
Interacting is kind of action that occurs as two or more objects have an effect upon on
another. Species interaction is the contact of species either positively or negatively. These
interactions between organisms that characterized particular communities and eco-system
have arisen as result of their evolutionary history.
Types of species interaction
i.
Negative interaction.
ii.
Positive interaction.
POSITIVE INTERACTION.
This is the mutual relationship between plant and animal, or plant and plant, animal and
animals.
Commensalisms.
It is the association between organisms of different species in which one species benefit
but does no apparent harm to its partner. For example Birds nest in trees, or epiphytes
grow on the branches of other plants. In general the host plant is unharmed while the
organisms that grows or nests on it benefit.
A common features of all commensally bacteria is that they take up. Sites in mammalian
body which disease –causing microbes might otherwise occupy. In this way they may
help to reduce the incidence of microbial diseases among mammalians. Example
Escherichia Cole – found in caecum helps in defection in human body and production of
vitamin.
Another example is when raids on a forest floor birds following army ants. As the army
ant colony travels on the forests floor, they stir up various flying insect species. As the
insect flee from the army ants, the birds following the ants and catch the fleeing insects.
In this way the ants and the birds benefit while the army ants are unaffected. Also
Orchids and mosses are plants that can have a commensally relationship with trees. The
plants grow on the trunks or branches of trees. The get the light they need as well as
nutrients that run down along the tree. As long these plants are not too heavy the tree is
not affected.
Cleaner animals, many species of African game, such as antelopes, buffaloes and zebras
are groomed by oxpecker birds which remove ticks and blood-sucking flies from their
hides. When predators come near, the birds alert the game by calling and flying off.
Therefore also the Africa game animals remain healthy due to removing blood –sucking
flies and ticks, also animals remain safe from predator.
As well Egyptian plovers and sanpipers have been observed talking leeches from inside
the open mouth of basking crocodiles on the river Nile. The birds are safe because
crocodile do not feed while they are lying out in the sun (hence plovers and sandpipers
act as a toothpick to the mouth crocodile)
Another example is Barber fish or cleaner fish, which plays an important role in keeping
many species of large fish in good health. They do this by picking off lice, parasite into
its mouth and even into its gills chamber to do its job.
Mutualism is an association between organisms of different species in which each
partner benefits. In the narrow sense, mutualism is often referred to as symbiosis. The
partner in mutuality associations are often so dependent on each other that they are
unable to live independently. One or both partner are some time found as free-living
organisms. For example; lichens are leaf like, hair like or crust like structure that grow on
the rock or the back of trees. Lichens may be gray green, black yellow, orange in color.
Although lichens appear to be single organisms in actual sense they are two different
organisms that live in close association with one another. Most common lichens one is
alga a microscopic producer that makes food by photosynthesis. The other partner is
fungus a consumer that gets its food from the alga but in return provides moistures to
alga. Both benefits no one is harmed.
Another example is pollinator mutualism like honey bee transfers male reproductive cells
(Pollen) from one plant to the female reproductive organs of another plant of the same
species. These animals are known as pollinators and without them the plants could such
as pollen or nectar for food. Thus both species benefit.
Also Roof nodules and nitrogen fixing bacteria, example of symbiosis; the bacteria get
into the roots through root hairs. They then cause cortex cells to divide forming nodules
in which the bacteria multiply. The bacteria fix nitrogen for plants nutrition.
Herbivorous animals and gut microbes
Ruminant mammals such as cattle, goat and sheep have complex stomachs. One of the
chambers is rumen. It is there that a variety of bacteria and protozoa live in millions.
(William & Simpikins,1990: 651).
Interaction also depends on the activity of the animal that lives among and are dependent
upon the plants growing in the particular area. Many plants depend on animals for seed
dispersal. Man deliberately produces new species of plants by the selection and
propagation of variants by the cross fertilization of different type of plant (Tivy,
1982:144)
Proto-cooperation interaction
Proto-cooperation is where two species interact with each other beneficially,” they have
no need to interact with each other, and they interact purely for the gain that they receive
from doing this”. It is not all necessary for proto-cooperation to occur growth and
survival is possible in the absence of the interaction that occurs, can be between different
kingdoms.
Interaction also depends on activity of animal that live among and dependant upon the
plants growing in a particular area. Many plants depend on animals for seed dispersal.
Man deliberately produces new species of plants by the selection and propagation of
variants and by the cross-fertilization of different type of plant. (Tivy 1982:144)
Another relationship of this kind involves ants & amphibian. Amphibian, also called
greenflies, are small insects that suck fluid from the phloem of living plants with their
piercing month parts. They extract a certain fluid but much runs out, in an altered form,
through their arms. Certain ants have taken advantage of this habit by domesticating the
aphids to new plants and using the honey-dew “ that they excrete as food.
NEGATIVE INTERACTION
This is the relationship where by one side a benefit while the other side is looses .there
are several species interaction which are negative. These are as follows:Parasitism:
A parasite is an organism that lives on or in the body of other organisms for nourishment.
Or a parasite is an organism which derives its food from other organisms called host,
while the host is still alive.
Example Ectoparasites, flees, licks live for most of their live cycle on the surface of their
host and Endoparasites live inside the host, like a tape warm, is an endoparasite living in
the intestine of a vertebrates host and absorbs the hosts digested food. In some cases the
host may be weakened by the presence of the parasites.
Physical damage to important organs such as the brain and lever is caused by the
hydrated cysts of flat worm parasites. Gut parasites sometimes damage the intestinal
mucosa, causing haemoid.
More over, a parasites plant is one that derives some or all of its sustenance from another
plant. About 4,500 species in approximately 19 families of flowering plants are know
parasitic plants have a modified root, the haustorium’s that penetrate the host plant and
connects to the xylem; phloem or parasitic plants are characterized as follow:Firstly Obligate parasite is a parasite that can not complete its life cycle without a host
example Nuystia floribunda ( Western Australian Christmas tree and mistletoe). Second,
facultative parasites, is a parasites that can complete its live cycle independent of a host
for example rhinanthus parasites (yellow rattle)
Also, stem parasite a parasite that attaches to the host stem.
Another is root parasite, is a parasite that attaches to the host rooted; hydriora species.
Then, Holophrastic a plant is completely parasitic on other plants and has virtuall no
chlorophyll eg. doddu parasite (Cuscuta Europe or the European dodder)
The last is hemi parasite which is a plant that is parasitic under natural conditions and is
also photosynthetic to some degree. Hemiparasites may just obtain water and mineral
nutrients from the host plant. Many obtain at least part of their organic nutrients from the
host as well.
In additional, blood sucking insects are the most notorious vectors of a range of human
parasites. Millions of people are affected annually with yellow fever and malaria, which
are transmitted by mosquitoes. The tsetse fly is the vector of sleeping sickness, black flies
carry liver blindness, while typhus is transmitted by the body louse. Sap sucking insects
such as aphids are the vectors of many viral diseases of crops
Predator-Prey interaction
This involve one type of organisms (the prey) is eaten by the other (the predator.) in this
relationship one organisms benefits from the relationship but the other does not
(Rasmussen,1989:61) .Example the lion is a predator that eats antelope, not only lion but
also other animals who eats other animals. (Prey), Birds as a predator eat insects
(Prey),Human being eat different (animals ) such as grass hopper, locusts and
(insects)like cows, goats.
Amensalism
Is a biological interaction between two species in which one impedes or restricts the
success of the other without being affected positively or negatively by its presence. It is a
type of symbiosis usually this occurs when one organisms exudes a chemical compound
as a part of its normal metabolism that is determine to another organism. The bread mold
pencillium is common example of this; pencillium a chemical that kills bacteria. A
second example is like black
walnut tree (Juglans nigra)which secrete jug lone a
chemical that harms or kills some species of neighboring plants from its roots. This
interaction may still increases the fitness of the non- harmed organisms though by
removing competition and allowing it to access to a greater scares resources. Another
example is when sheep or cattle make trails in grass that they trammel on and without
realizing they are killing the grass. Allelopathy is also an example of amensalism where
plants produce some toxic materials that are called Allelo chemical this chemical inhibit
the growth of other plant in particular area. It affect the process of germination of other
plant.
Herbivores
These are animals that are adapted to eat only plants. Herbivores is a form of predation in
which an organism consumes principally autotrophy such as plants, algae and
photosynthesizing bacteria as Primary consumers. It is important to remember that much
of the interaction of herbivores and plants is negative with one individual and the fitness
of the other. It is regarded as negative because it destroys the existing plants and affect
their distribution.
CONLUSION
The knowledge of species interaction is very important not only to scholars but also he all
community as far as ecosystem is concerned. This is because animals and animals, plants
and plants or animals and plants depend on each other. For instance predators should not
be more than pasture (herbs).To solve this government has to form department and
ministry to deal with balance of ecosystem eg. TANAPA,KINAPA and ministry of
Tourism and natural resources. The balance among animals in wild lie is known as game
chopping.
Q3; Species as a group of organisms all sharing the same morphology which are
potentially able to breed amongst themselves but not with any other species, or Species is
a set of animals or plant organisms in which members have similar characteristics to each
other and can interbred to produce a fertile offspring.
Then speciation are formed on the earth’s surface over time and spaces therefore,
speciation is the evolutionary formation of new biological species usually by one species
of plants or animals that divided into two or more species which are genetically and
phenotypically unique.
Extinction is the total disappearance of all members of a species or higher taxonomic
group. Extinction can also be defined as the disappearance of organisms of a certain
environmental condition. However extinction occurs when a last
Organisms of a certain species dies, example the last zebra of Quagga specie found in
south Africa died in capacitivity in 1883.
Both speciation and extinction control distribution of plants and animals species on the
earth’s surface in different or various ways. Under the ideas of speciation, there are
various events that occur and make the existing species of plants and animals to become
sub-divided and forms new species. Hence, speciation controls distribution of plant and
animals species in the following ways with regards to different modes or types of
speciation.
Allopathic Speciation is a situation where by barrier such as a stretch of sea, river or
mountain range separate a population of a particular specie. This means that population
spilts into two or more geographical are and become prevented from breeding as they
can’t cross the barrier, this makes the separated population to undergo genotypic or
phenotypic divergence /difference and independently undergo genetic drift which make a
new organisms. Then when the population come into contact, they can’t breed as they
have reproductively isolated and no longer capable to exchange gene, Example a pupfish
lived in the Death valley of California which contained interconnected ponds and rivers
produced different new species of pupfish’s in the rivers and ponds, after the water /death
valley had dried up and prevented connection of water bodies. Therefore, plants and
animals species are distributed in various areas if there is such an incidence of
geographical isolation of organism.
However, allopathic process can occur in other different form and bring the emergence of
new species of organisms
Adaptive Radiation: is the emergency of numerous species from a common ancestor
that spread to several new environments. This method of radiation explains another form
of allopathic speciation because members of species quickly disperses to take different
advantages of niches or different ways of obtaining food and shelter, the dispersed
species will be in different habitats, and food materials, they greatly adapt the
environment they have taken direction, then over time and space the environment can
influence their genetic changes and lead to the formation of new species, example
:Darwin (1835) discovered various species of finch birds in South Africa in Galapagos
Island, these finches were from common ancestor and they formed 14 new finch species
due to the effect of adapting the environment which made them to have different beaks.
This indicates that, animals species can be distributed if adaptive form of allopatric
process favors.
Sympatric Speciation, Grant (1981) explains that in this form of speciation process,
separation of organisms is non- geographical but more behavioral, therefore isolating
mechanism genetic modification, but Soans (1974) Insisted that sympatric speciation
govern animals and plant species distribution with regards to genetic modification, he
explained it with such a example that, in case of animals, like herbivores insects will lay
some eggs on a particular plant and when a larvae hatch they have eggs on another space
of plans, the generation formed will be different to the former and they can not mate, this
is due to genetic change influenced by that particular plant which may also favors colors
those new formed insects which will be unique from one another .
A part from that, it has been explained that sympatric process does controls animals and
plants species distribution in other different forms which still cause the emergence of new
species.
Another major reasons for distribution of animals and plants species over time and
species is extinction:Extinction controls animals and species of plants distribution with
regard to the following natural factors.
Natural factors for extinctions
These include non human induced causes, they occur naturally.which are the following
Diseases, every organisms have defense mechanism like immunities and ability to fight
diseases. With the changing climate and land scape, certain species are loosing their
ability to fend off diseases and lead to their eventual extinction, example –the yellow
diseases is very hazardous to plants species with oft leaves in equatorial areas and it
depletes many of the plants.
Volcanic eruptions: if volcanic eruption takes place violently it could hamper the near
by species of plants and animals species. Volcanic eruption can cause extinction if it only
occurs in areas where the final species of organisms are found. The most famous example
of volcanic eruption is Mauna Loa Volcanic of Hawaii Island in 983 which marked the
end of Dinosaurs that survived 65 million years ago.
Earthquake, the sudden trembling of the earths crust, quake is catastrophe that costs
animals lives, if a quake occurs with a huge magnitude many species of plants and
animals may perish. Therefore in areas where quakes occur frequently is said to have no
species of plants and animals /have poor distribution of plants and animals
Predation. It as a capture and consumption of organisms by other organisms to sustain
life. If predators consume a lot of prayers, it is evident that their prey will be extinct,
because predators consume them than their rate of production.
This means that
introduction of many predators in a given areas will clean up some preys which can also
lead to co extinctions example if lion feeds much on antelope, the consumed species will
disappear this will mark the start of Co-Extinction, this can be either a natural or human
induced factor it explains that the loss of a species as a consequences of extinction of
another. If the prey has been extinction either by human factors or natural factors, it is
obviously that the predator which much depended on that prey will lack food supply and
hence will face out and be extinct, example the extinction of passenger pigeon in some
part of North America was caused by extinction of bird lice, Heats Eagle with the Moa.
(Ann 1982) This indicates that animals and plants distribution will also depends on the
factors of Co-extinction.
Human factors for extinction
Human activities are mostly responsible for prescient for extinction rates. Brian sees the
top human induced causes for extinction as:Acidic rain: this occurs when sulphur dioxide or nitrogen oxides are put out into the
atmosphere especially due the industries activities, these chemicals get absorbed by water
droplets in the clouds and eventually fall to the earth’s surface as acidic precipitation,
which increase acidity of the soil and lets species of plants and animals get affected. It
can also affect rivers and lakes (Water bodies) and kill some vulnerable aquatic organism
in that environment. This underlines that, plants and animals species will be distributed in
areas with no rain of acid content because some plants are vulnerable to acids. An
example of this, is seen in Middle East where many plant species were depleted.
Habitat destruction, every organisms need a comfortable environment to sustain its life,
due to various reasons including discoveries it had lead to environmental pollution, and
many of species lacked conducive settlement and hence survival become worse, as the
result, the animals and plants species are unable to develop, this shows that animals and
plants are well distributed where habitats destruction is kept minimal. Example the
Quagga ( equus guagga) was a type of Zebra native to South Africa it was extincted in
1600’s due to habitat destruction.
Increase of population, as the population become higher, some plants species can be
destroyed as the result of competition for agriculture, building materials over which
forest will be cleared, for which even lumbering and using trees or some plants as sources
of fuels greatly increases the rate of extinction. Man as Herbivorous creature has been
greatly depending on some animals as sources of food, this includes antelopes, then if the
population increases can lead to disappearance of these animals which are depended on
by man at large
Hunting and illegal fishing/ poaching this has lead to total removal of some species of
specials animals. When animals species are consumed than their rate of predation, they
will easily be faced out. Poaching is a dominant case in many Africa countries where
some elephant have been a victim of this. Many of the African elephant are due to the
increases of their horns based traders, and hence on the way to disappear, therefore
animals will be well distributed where there is no poaching and uncontrolled hunting
which is sometimes done by fires. Poor fishing method is another reasons for extinction
because it is done using poor fishing nets and sometimes poisons that affects intended
and unintended biodiversity is used and so, distribution of species of fishes will depend
on their rates of being consumed
In other cases animals and plants species, the use of ABC (atomic, biological and
atomic), the chemicals inhibits survival of plants and animals due to poison
Emitted, example, the Atomic bombs during WW11 in 1945 affected many plants and
animals species in Japan, The weapons has made the soil to become less/ not fertile and
so very poor for agriculture and growth of other plants species which could provide food
for fewer animals that can be found thee.
Climate change, This can be contributed human or natural factors, so far climate change
due to natural factors is less destructive, in this context it is agreed that human being is a
key causative of extreme global climate change which has greatly brought many effects
including death/ extinction of animals and plants species, global increases of temperature
has lead to massive death of Polar bear species which are vulnerable to high temperature,
large amount of snow covers has lead to disappearance of some animals and plants,
likewise the presence of storms has destroyed many plant species.( Maureen
Mandelstam)
Biological factors for extinction
This was discovered by Theophrastus (300 B.C) who was a student and successor of
Aristotle, ha has been the must known father of Botany. In his botanical works he
explained that some plants are Allelopathy and can exhaust soil and destroys weeds
because these plants produces chemicals which are harmful for survival of other plants.
The word Alelon means”of other” and pathos means then allelopathy refers to the
chemical inhibition of one species by another. In this case it is true that in areas where
Allelopathy plants is dominant there is great possibility that some other plant species can
be a wept off the earth’s surface due to poisonous chemical released by these plants,
example, the most famous Allelopathic plants is Black walnut (Juglans nigra) which
produce Toxic chemicals known as Jug lone (Foliar) which lead to yellowing and death
of the near by plants
Effects of extinction of animals and plants species
There has been extinction throughout the history of the earth, many animals has already
gone extinct million of years ago and others will continues to extinct as lives goes on due
to the causes that leads to extinctions as we seen above. In this regards observe the
following affects;
Some species are very important to human being, being beneficial to human we
considers animals like Frogs of which most of than lives on diet of insects and in many
areas they help control of population of mosquitoes and crop damaging insects, also in
turn they may be of food sources for humans example the legs of Darwin’s Frog are
considered a delicacy in many parts of Europe.
Loss of genetic diversity, the dramatic loss of some species poses a threat to gene pool
which imperil both animals and plants in agriculture, omission of gene pool will greatly
affects some species of plants and animals, example in 1846 there occurred the Irish
potato famine in Brazil which was caused by loss of genetic diversity because many
products came from single materials plants.
Economic loss, it is true that some countries greatly depend on tourism to collect huge
amount of money/income, this is due to the fat that in some areas many specials species
have been reserved and as the results tourists get attracted and have to move there to see
and enjoy those species of animals or plants, example, at Gombe National Park in
Kigoma region- Western Tanzania , there are some species of Gorilla which attract many
tourists who helps in earning foreign currency. Therefore the loss of these species (50
animals ) would diminish amount of foreign currency to our nation, likewise the extinct
of Red-Asiatic Lions species in1990 has posed economic crisis to the Gir National Park
in Gujarat (India )
Some species go extinct before they are not known to scientists for further studies and
researchers; this will reduce expansion of human knowledge and understanding of
various species of animals and plants which could be of great importance to human being
and development of science and discoveries. Likewise the extinct of Green banded –
Glass Frog which was famously used to teach science due to it s transparent body has
disturbed the study because it dint need to operation as its internal organs were clearly
seen including the tiny beating Heart. This species of Frog was a tree dweller in central
and South America, its eggs were used in the study of embryonic development, Ecologist
and scientists who study earth’s living ecosystem were interested in the this type of frog
and other amphibians because they are bioindcatiors.
Loss of resources for medicine discovery, many plants species are used in discovery of
antibiotics medicine, the science of medicine has depended much on plant species,
example, in 1922, Scottish bacteriologist and a Noble prize winner of the field of
medicine at St.Mary’s Medical School of the University of London Professor Alexander
Fleming discovered that Penicillium mold produces a substance that has an antibiotic
effects and the value of this substance were called penicillium which have direct effects
on bacteria. Therefore depletion some penicillium plants has reduced the gear of
treatment because scientists has pledged that penicillium offers great resistance to
bacteria
Disruption of an ecosystem. the exchange of materials among the community of
organisms and non living organisms will be affected due to extinct of some animals and
plants species, organisms are interdependent in nature, example the disruption of bacteria
in the soil will affects some plants growth of which herbivorous like Antelopes could lack
food and hence un able to survive, the effects spread to Carnivorous like Lions which will
suffer food shortage of food and hence could under go extinction (Redmod.2009)
Generally it can be said that, speciation and extinctions are key determinants of animals
and plants species distribution on the earth’s surface and then a form of speciation will
guide the nature of plants and animals in a given geographical area over time, meanwhile,
human activities is a major factor for extinction of animals and plants species on the earth
because it has led to serious environmental changes perpendicular with climate change
which extinct animals and plants in various ways such that, high temperature, high
humidity, floods and doughtiness. However speciation has a great important to man, this
is because new species of organisms involve and can be consumed by man and increase
resources for this survival, but extinction can be of positive side if it includes the
removal of animal species that seriously affects man’s life. For endangered species
reserve centers like the one found in Kigoma region –western Tanzania where they
expensive 100 animals of Gorilla species has been reserved.
Q4. (a) CARBON CYCLE
Carbon cycle is the global movement of Carbon between a biotic environment including
the atmosphere and organisms. Carbon cycle explains on how an element carbon atom
circulates continuously within the physical and biological world. Carbon cycle is based
on the carbon dioxide which makes up only about 0.03% of atmosphere. Carbon makes
up approximately 0.03% of atmosphere as gas, carbon dioxide (C02). It is also present in
the ocean as dissolved carbon dioxide, that is carbonate (CO3) and bicarbonate (HCO3)
and in rocks such as limestone.
DESCRIPTION OF CARBON CYCLE
During photosynthesis, plants, algae and certain bacteria remove carbon dioxide from air
and fix or in incorporate it into complex chemical compounds such as sugar. The overall
equation for photosynthesis is
6CO2 + 12H2O
Light
C6H12O6 + 6O2 + 6H2O
(SUGAR)
Plants use sugar to make other compounds, thus, photosynthesis incorporate carbon
dioxide from the a biotic environment into the biological compounds of the producers.
Those compounds are usually used as fuel cell respiration by the producers that made
them, by consumers that eats the producers or by decomposers that breakdown the remain
of producers or consumers. The overall equation for cell respiration is
C6H12O6 + 6O2 + 6H2O
6CO2 +12H2O+Energy for biological
work.
Thus carbon dioxide is returned to the atmosphere by the process of cell respiration.
Sometime the carbon in biological molecules is not recycled back to the a biotic gasses
called fossil fuel because they formed from the remains of ancient organisms are vast
deposit of carbon compounds, the end products of photosynthesis that occurred millions
of years ago.
The carbon in coal, oil and natural gasses and wood can be returned to atmosphere by the
process of burning or combustion. Thus photosynthesis removes carbons dioxide from
the a biotic environment and incorporates it into biological molecules and cell respiration;
combustion and erosion return the carbon in biological molecular to the water and
atmosphere of a biotic environment.
HOW MAN AFFECTS CARBON CYCLE
Exhaust of vehicles and other locomotives
These produce fumes of carbon dioxide and other gasses from petrol and diesel engines
to the atmosphere especially when badly tuned, emit smoke and fumes which often gather
to the atmosphere as dust, where some covers the leaves of plants and harms or kills them
by cutting off their light and so limiting photosynthesis and block their stomata. Some
dusts from vehicles inhaled by people and if present in high concentration may cause
genow respiration ailment and eye irrigation in people. For example in USA 1952 many
other plants.
Burning of garbage’s
These include the burning of papers, home cleanings, medicine disposal and toxic
materials. Each burn can release more poison to the atmosphere; hence disturbs the
carbon dioxide. This leads to imbalance between total gross primary production and
respiration cost (respiration Vs photosynthesis). Explain in US garbage burning makes
more carbon dioxide than industrial sources.
Industrial activities.
Since the industrial revolution, the concentration of carbon dioxide in the atmosphere has
been increased as a result of combustion of fossils fuels. For example coal, natural gas,
gasoline, hence disturbs the natural circulation of carbon cycle. This also leads to
imbalance between total gross primary production and respiration cost.
Deforestation
Is the clearance of naturally occurring forest by logging and burning. These trees are cut
down for different activities such as agriculture, settlement and construction of roads.
Deforestation affect natural pattern of circulation of carbon cycle as follows :Carbon is fixed to the atmosphere in a given amount but it tends to increase more rapid
due to deforestation. Trees are used to balance the carbon at the atmosphere by trapping
carbon dioxide and use it in the manufacturing of their own food through photosynthesis
process. Nowadays trees are logging and burnt led to the accumulation of CO 2 to the
atmosphere. Without tree there will be a decrease in evaporation and therefore no water
vapor in the air.
The release of carbon by the burning of trees contributes to greenhouse effect and global
warming. Sources of CO2 is deforestation and burning of the tropical rainforest.
Burning of forest
Is the process of putting fire on the vegetation in the given area for the purposes of
agricultural activities or hunting and chasing away dangerous animals near people’s
places of living. In doing so, a lot of smokes goes to the atmosphere to add more carbon
dioxide which leads to the destruction of natural cycle of carbon dioxide in the
atmosphere .
Domestic Activities
The use of firewood, cow dung, charcoal and kerosene in cooking and heating water
produce smokes to the atmosphere which led to the increase of the natural carbon dioxide
hence it disturbs the carbon cycle.
Generally, human activities have disturbed the balance of carbon cycle. From the advent
of the industrial revolution to the present, humans have burned increasing the amount of
fossil fuels such coal and natural gas. This trend, along with great combustion of wood as
a fuel and the large sections of the tropical forest has released carbon dioxide into the
atmosphere at a rate greater than the natural carbon cycle can handle. The slow and
steady rise of carbon dioxide in the atmosphere may cause changes in the climate called
global warming.
Global warming could results in rise in sea level, changes in precipitation patterns, deaths
of forests, extinction of organisms and problems for agriculture. It could forces the
displacement of thousands or even millions of people, particular from coastal areas.
(b). PHOSPHOROUS CYCLE.
Phosphorous cycle is the biochemical cycle that describes the movement of phosphorous
through the lithosphere, hydrosphere and biosphere. Unlike many other biochemical
cycles the atmosphere does not play a significant in the movement of phosphorous
because phosphorous compounds are usually solid at the typical range of temperature on
the Earth.
Two depicts of phosphorous cycle.
Soil based view of the phosphorous cycle.
Initially phosphates weather form rocks. The small loses in a terrestrial system caused by
leaching through the action of rain are balance in the grains from weathering rocks. Soil
phosphate is absorbed on clay surface and organic matter particles and becomes
incorporated (mobilized). Plants also dissolved ionized form of phosphate, herbivores
obtain phosphate from plants and carnivorous eat herbivores and herbivores excrete
phosphorous as waste product in urine and faces. Phosphorous is realized back to the soil
when plants or animals matter decomposes and the cycles repeats .
An ecosystem view phosphorous cycle.
The ecosystem phase of phosphorous cycle is that all organisms require phosphorous for
the synthesizing energy (ATP) adenosine triphosphate. Plants absorb phosphorous very
quickly and then herbivores get phosphorous by eating plants.
Carnivores get
phosphorous by eating herbivores. Eventually both of these organisms will excrete
phosphorous as waste products, this decomposition will release phosphorous in to the
soil. Plants absorb the phosphorous from the soil and recycle it within the ecosystem.
HOW MAN AFFECTS PHOSPHOROUS CYCLE
Sewage disposal
Industrial by- products are discharged in lakes, streams and groundwater. This detergents
which contain different chemicals like phosphates may flow into oligotrophic lakes and
lead to their entrophication of water quickly .
Domestic waste products
Waste products from domestic activities which accumulated in municipal dustbins and
outflows from municipal sewage treatment plants, without an excessive tertiary
treatment, the phosphate in sewage is not removed during various treatment operations.
Again an extra amount t of phosphate enter the water. These chemicals can accumulate in
fish and other aquatic creatures and then spread along other organisms such as water
birds, turtle and whale. Is an increase in the concentration of chemicals nutrients in an
ecosystem to an extent that increases primary productivity of the ecosystem.
Fertilizers
The introduction use of commercial synthetic fertilizers influences on the phosphorous
cycle. The phosphates Is obtained through phosphate mining of certain deposit of calcium
phosphate called apatite. Huge quantities of sulphuric acid are used in the conversion of
the phosphate rock into fertilizer product called supper phosphate, since organic
fertilizers contain many compound may lead to less beneficial, even harmful because if
used excessively, they can lead to the breakdown of soil and the formation of inorganic
acids in the soil.
Pollution of sea due to navigation.
The pipes that transporting oil other marine vessels sometimes may leak as a result death
of aquatic animals when water contaminated with oil. For example, over the past 20 years
marine life in Spain territorial waters mostly fishes died and increased the amount of
phosphorous and therefore affect phosphorous cycle.
Agricultural activities.
In modern agriculture, pollutants in soil include chemicals in crop sprays such as Iron
phosphate, Zinc phosphate and Potassium de- hydrate phosphate used to kill insects and
fungal pests (Pesticide and herbicides). If these chemicals are washed to local river and
pounds and they disrupt food chain in the same way as industrial wastes.
Fishing by using dynamites and theodane
This chemical is dangerous to fish and aquatic animals.
-it destroys coral reefs which are the food for fish and damage their habitat
-this chemical decreases the amount of oxygen in water. As a result Marine animals die
through suffocation. Hence destroy the natural phosphorous cycle
Q5. BIOGEOCHEMICAL
Biochemical is the scientific discipline that involves the study of the chemical physical
geological and biological processes and reactions that govern the composition of the
Natural environment including the biosphere, hydrosphere, the pedosphere, the
atmosphere and the lithosphere. In ecology and earth science a biogeochemical cycle or
nutrients cycle is a pathway by which a chemical element or molecules moves through
both biotic (biosphere) and a biotic (lithosphere, atmosphere and hydrosphere ).
(a). NITROGEN CYCLE
The nitrogen cycle is the processes by which nitrogen is converted between its various
chemicals forms. This transformation can be carried out via biological and nonbiological processes. Nitrogen cycle occupies 78% of all gasses in the atmosphere.
However, atmospheric nitrogen is unavailable for biological use, leading to scarcity of
usable nitrogen in many types of ecosystem.
NITROGEN CYCLE PROCESSES
Nitrogen is present in the environment in a wide variety of chemical forms including
organic, ammonia (NH4+), nitrate (NO3-) and nitrogen gas (N2). Many of the processes
are carried out by microbes either to produce energy or to accumulate nitrogen in the
form need for growth .
There are four important processes in the nitrogen cycle which are:
Fixation

Mineralization

Nitrification and

Denitrification
NITROGEN FIXATION
Atmospheric nitrogen must be processed or fixed in order to be used by plants. Some
fixation occurs in lighting strikers, it most fixations are done by free-living or symbiotic
bacteria. These bacteria have the nitrogen’s enzymes that combines gaseous nitrogen with
hydrogen to produce ammonia, Some nitrogen fixing bacteria, such as Rhizobium, live in
the root nodules of legumes such as peas or beans.
CONVENSION OF NITROGEN
There are for ways to convert nitrogen (atmospheric nitrogen gas) into more chemically
reactive forms

Biological fixation.
Some symbiotic bacteria (most associated with leguminous plants) and some free- living
bacteria are able to fix nitrogen as organic nitrogen. An example of mutuality nitrogen
fixing bacteria is the Rhizobium bacteria. Which live in root nodules.

Industrial Nitrogen fixation
Under great pressure, at a temperature of 600c and with the use of iron catalyst,
(atmospheric,) atmospheric nitrogen and hydrogen can be combined to form ammonia
(NH3), which is used to make fertilizer and explosives.

Lighting.
Lighting can fix nitrogen. The high energies provided by lighting and cosmic radiation
serve to combine atmospheric nitrogen and oxygen into nitrates. Which are carried to the
Earth’s surface in precipitation.

Assimilation
Some plants get nitrogen from the soil and by the absorption of their roots in the form of
either nitrates ions or ammonium ions. Animals, fungi, and other heterotrophic organisms
absorb nitrogen as amino acids, nucleotides and other small organic molecules.
AMMONIFICATION /MINERALIZATION
When plants die an animals dies, or animals expels waste, the initial form of nitrogen is
organic. Bacteria convert the organic nitrogen within the remains back into ammonium.
NITRIFICATION
The conversion of ammonium to nitrate is performed primary by soil- living bacteria and
other nitrifying bacteria. the oxidation of ammonium (NH4+) is the primary stages of
nitrifications which is performed by bacteria such as Nitrosamines species which
converts ammonia to nitrites (NO2-) other bacteria species such as the Nitrobacteria are
responsible for the oxidation of nitrites into nitrites (NO3-). Due to high solubility,
nitrates can enter ground at water.
DENITRIFICATION
Denitrification is the reduction of nitrates back into the largely inert nitrogen gas
(N2),completing in the nitrogen cycle. This is performed by bacterial species such as
Pseudomonas and Clostridium in anaerobic conditions. They use the nitrate as an electron
acceptor in the place of oxygen during respiration.
ANAEROBIC AMMONIUM OXIDATION
In this biological process nitrate and ammonium are converted directly into denitrogen
gas. This process makes up a major proportion of denitrogen conversation in the oceans.
FORMS OF NITROGEN AVAILABLE TO LIFE
Plants and algae can use two organic forms of nitrogen, ammonium (NH+4) and nitrate
(NO2-). Animals can utilize only organic forms of nitrogen such as amino acid or
proteins.
HUMAN IMPACTS IN NITROGEN CYCLES

-Man can disturb nitrogen by cutting or consuming plants which add
nitrogen in soil legumes plants.

-Extensive cultivation of legumes soy, alfalfa, and clover which can
add more nitrates by the effects of bacteria

-Extensive use of industrial fertilizer for example, urea.

-Over harvesting of lea gums and nitrogen –rich mine to the reduction
of nitrogen.
As a result of extensive cultivation of lea gums particularly soy, alfalfa, and clover,
growing use of the Herber –Bosch process in the creation of chemical fertilizer, and
pollution emitted by vehicles and industrial plants, human beings have more than double
the annual transfer of nitrogen into biologically available forms. Ammonia (NH3) in the
atmosphere has tripled as the result of human activities. It acts as an aerosol decreasing
air quality and clinging on to water droplets, eventually resulting in acidic rain.
(b). WATER CYCLE
Water cycle is the series of movements of water above, on and below the surface of the
Earth. Water cycle is the endless in change of water between the sea, the atmosphere and
the land.
The circulation of water is carried out in the following processes:
Evaporation: This tales please on open water surfaces like oceans, seas, lakes, ponds,
rivers, and swamps. The water is changed into water vapour by the suns heat and then it
rises into the atmosphere.
Some water vapour is also added to the atmosphere from the soil through direct
evaporation and through transpiration by plants. This loss of water through these two
processes combined is called evapo-transpiration.
Condensation:When the cool of the water vapour continues to below dew points, the
vapour turns into trey water droplets. These droplets join together in large qualities to
form clouds (Kibuuka P. 2004:73)
Precipitation:Precipitation occurs when water vapour in the atmosphere condenses into
clouds and falls to the ground. The processes of precipitation returns water to the ground
in the form of rain, hail, snow, and ice pellets.
Surface run off: Water that flow down streams, river, valleys, ponds lakes, swamps, and
sea is called surface run off.
Clouds
SIGNIFICANCE OF THE WATER CYCLE:
Maintaining atmospheric energy:
The amount of water vapour is the atmosphere determines the amount of energy stored in
the atmosphere for the development of storms.
Absorbing terrestrial radiation.
The moisture in the atmosphere is important in absorbing terrestrial radiation. This
regulate heat being lost from the ground by reflecting most of it back to the earth this
keeps the lower atmosphere warm. Hence the moisture for the atmosphere is therefore
very significant in heat circulation.
Water is important for life to exist on the earth. Interference with the hydrological cycle
has far –reaching consequences on climate there is reduced precipitation. This in turn
may lead to arid conditions and eventually to desertification.
HUMAN EFFECT ON WATER CYCLE:
Wells are dug to obtain water from the ground, Excessive pumping from the wells has
drastically lowered the water table depleting some ancient water supplies irreversibly and
causing the intrusion of salt water into ground water intensely populated low lying
coastal regions
Agriculture, as human being cultivating the water catchments areas there is destructions
of water cycle system, agriculture activities include crops cultivation and animals
husbandry. The crop cultivation deal with clearing of the bushes, cutting of trees and
burning. In animals husbandry there is overgrazing, all these activities reduces the rate of
vapor- transpiration.
Evaporation of water behind dams is a serious source of water loss. Increasing
urbanization has lead to more severe flooding because rain water reaches streams more
rapidly and in a greater quantity from areas where the ground has been paved.
Deforestation
It is the clearance of the naturally occurring forest by logging and burning. This is due to
charcoal making and clearing land for pasture.
The causes of deforestation were urbanization, Population growth, corruption of
Government and globalization. All these resulted to the decreases of evaporation as far as
many water are lost
CONCLUSION;Generally, The human struggle for survival has resulted to the
disturbance in the Nitrogen cycle. The same man have lead to disturb of water cycle in
which the source of water are being disturbed. This can result to drought, acidic rains,
floods and different part of the world.
Q6.Photosynthesis literally means to make with light. It is the process by which plants
and some other organisms convert light energy from the sun into chemical energy stored
in molecules like glucose, a simple sugar. Photosynthesis takes place in an organelles
called chloroplasts. The chloroplasts contain chlorophyll, the pigment that gives plants
their green color.