Download Biology 13 to 16 - Dominican

Biology: 13. Structure and transport in plants
Syllabus
OB45 Identify the main parts of a typical flowering plant and their functions; the root, stem, leaf and flower
OB46 Understand that the xylem transports water and minerals in the plant and that the phloem transports food
OB47 Carry out simple activities to show the path of water through plant tissue, and show that water evaporates
from the surface of a leaf by transpiration
Student Notes
The main parts of a flowering plant are the root, stem, leaf and
flower
Root:
1. Anchor and support the plant in the soil.
2. Take in (or absorb) water and minerals.
3. Some plants (e.g carrots and turnips) store food in their roots.
Stem:
1. Support and hold up leaves and flowers
2. Transport water and minerals from the roots to the leaves and also
transport food from the leaves to the roots
3. Some stems store food (e.g. potatoes)
Leaves:
1. Make food in a process called photosynthesis
2. Allow gases and water vapour to pass in and out
3. Some leaves store food (e.g. lettuce and cabbage)
Flowers:
The function of a flower is to produce seeds so that the plant can
reproduce.
Xylem and Phloem
Plants have two types of transport tissue: xylem and phloem
The xylem transports water and minerals up the plant while the phloem transports food from the leaves
Water Transport
Water is carried in tiny tubes throughout a plant. These tubes allow a continuous flow of
water from the roots to the leaves of a plant. The tiny tubes appear as the veins in a leaf.
To show that roots absorb water
Set up as shown
Leave for a week (the oil prevents water loss from evaporation).
The level of water will have dropped in the tube..
To show the movement of water in plants
Place a stalk of celery with leaves attached into a beaker of water (which has food
colouring to make it visible).
After a few days the top of the stalk and leaves go red, showing that water rises up the plant.
1
Transpiration
Transpiration is the loss of water vapour from a plant
Tiny openings (called stomata) on the lower surfaces of leaves allow water to evaporate from leaves into the air.
This loss of water is called transpiration.
Transpiration supplies water to the leaves for photosynthesis.
Transpiration helps to cool plants (in the same way sweating helps cool the human body).
To show that water evaporates from the surface of a leaf by transpiration
Place a dry plastic bag around the upper part of a plant as shown.
After a few hours a liquid will have formed on the inside of the bag.
Test using cobalt chloride paper.
It will turn from blue to pink indicating that the liquid is water.
Factors that increase rate of transpiration
Sunlight, wind, soil water and low humidity
Exam Questions
1. [2008 OL]
Name the parts of the plant labelled X and Y in the diagram.
2. [2008]
Phloem and xylem are plant transport tissues.
Name a substance, other than water, that is transported in (i) phloem and (ii) xylem.
3. [2008 OL]
Describe, with the help of a labelled diagram, how you would show the path of water upwards through a plant or a
part of a plant.
Use the following headings: Equipment, Procedure, Result.
4. [2006 OL]
The plant in the test tube drawn on the right was allowed stand in the laboratory for a few days
to investigate the transport of water in the plant.
(i) Which part of the plant takes in water?
(ii) What would you notice about the level of water in the test tube after a few days?
(iii) Why is it necessary to put oil on the surface of the water in the test tube?
5. [2006]
Water vapour evaporates from cells in the leaves of plants and exits the leaves by way of tiny
pores in their leaves.
(i) What is this process called?
(ii) How would you test the drops of liquid inside the plastic bag covering the shoot of the plant
shown in the diagram to show that the drops are water?
2
Biology: 14. Plant Reproduction
Syllabus
OB51 Distinguish between asexual and sexual reproduction in plants and describe a way in which a named plant can
reproduce asexually
OB52 Locate and identify the main parts of the flower: sepals, petals, carpel and stamen
OB53 Use a suitable flower to identify the stigma, style, ovary, anther and filament
OB54 Understand that the stamen (anther) produces pollen, the carpel (ovary) produces the egg cell, the pollen
produces the male gamete for fertilisation, the ovary produces the female gamete for fertilisation, and pollen is
transferred by wind and by insects
OB55 Recall that seed formation follows fertilisation, and describe seed dispersal
OB56 Describe seed structure (testa, food supply, radical, plumule)
OB57 Understand that seed germination is necessary to produce a new plant
OB58 Investigate the conditions necessary for germination
Student Notes
Asexual reproduction involves the formation of new individuals from the cell(s) of a single parent.
Examples of plants that reproduce asexually include grass, strawberries, daffodils, onions and potatoes.
All plant organs have been used for asexual reproduction, but stems are the most common.
Other organs used for asexual reproduction include runners (strawberries), bulbs (onions) and tubers (potatoes).
Part
Stamen (anther)
Function
produces pollen
Carpel (ovary)
produces the egg cell
Pollen
Ovary
Seed dispersal
There are many ways in which pollen can get transferred from one plant to another
Wind
Dandelions use wind for dispersal
Dispersal
Wind
Insect
Example:
Dandelion
Colourful flowers use bees for dispersal
Bees visit flowers to collect pollen then land on another plant
The pollen lands on the stigma of the second plant.
3
produces the male gamete for
fertilisation
produces the female gamete for
fertilisation
Insect
Strawberry
Self
Peas
Structure of a seed
Describe seed structure (testa, food supply, radical, plumule)
Germination
Germination is the process whereby a seed emerges from dormancy
Moisture, oxygen and heat are necessary for germination
To investigate the conditions necessary for germination
Procedure:
1. Place cress seeds in cotton wool in each test-tube.
2. Add moist cotton wool to one
3. Add water which has cooled after boiling to another and cover it with oil (this means there will be no oxygen).
4. Add dry cotton one to another (no water).
5. Keep another in the fridge at 40 C (no heat).
Result: Only the test tube containing the moist cotton wool at room temperature germinated.
Conclusion: Moisture, oxygen and heat are necessary for germination
4
Exam Questions
1. [2009]
(i) Name a plant that can reproduce asexually.
(ii) Describe the way the plant that you have named reproduces asexually.
2. [2007 OL]
Name the parts labelled A and B in the diagram of the flower.
3. [2006 OL]
(i) Name the part of the flower labelled A in the diagram.
(ii) Give one reason why insects are attracted to flowers.
4. [2006 OL]
Plants produce a wide variety of seed types which need to be dispersed (scattered) in order to
avoid competition.
(i) Identify how the seeds A and B in the diagram are dispersed.
(ii) Name one resource that seeds must compete for with the parent plant.
5. [2008 OL]
Seeds are dispersed in different ways.
(i) In the table on the right write the letter W under the seed that is dispersed by wind.
(ii) Write the letter A under the fruit whose seeds are dispersed by animals.
6. [2009]
The child in the photograph is helping a dandelion to disperse its seeds.
(i) Why is seed dispersion important for plants?
(ii) Give a second way, excluding wind, by which plants disperse seeds.
7. [2007]
List three conditions necessary for seeds to germinate.
8. [2006 OL]
A number of cress seeds were set up as shown
in the diagram and left for a few days to
investigate the conditions necessary for
germination.
Test tubes A, B and D were kept in the
laboratory at room temperature.
Test tube C was placed in the fridge at 4 °C.
(i) Why do only the seeds in test tubes B germinate?
(ii) Why is the water in test tube D boiled before use?
(iii) Explain why the seeds in test tube C failed to germinate.
(iv) Why is this investigation considered to be a “fair test”?
9. [2007 OL]
A number of cress seeds were set up as shown in
the diagram and left for a few days at a suitable
temperature to investigate one of the conditions
necessary for germination.
The seeds in test tube B germinated.
Study the diagram and answer the questions below
using the table.
(i) Write the letter X in the table beside the condition present in B but not present in A which allowed the seeds in B
to germinate.
(ii) At which temperature, 1 °C or 15 °C, would the seeds be most likely to germinate?
Write the letter T in the table beside your choice.
10. [2007]Describe using labelled diagrams an investigation to show that any two of the conditions that you have
given are required for seeds to germinate. The investigation must have a suitable control.
5
Biology: 15. Ecology
Syllabus
OB59 Study a local habitat, using appropriate instruments and simple keys to show the variety and distribution of
named organisms
OB60 Understand that living things are affected by their environment and respond to changes that occur in that
environment, and understand that their numbers depend on the availability of food and the presence or
absence of other organisms
OB61 List examples of producers, decomposers and consumers in an ecosystem
OB62 Select a food chain and a food web from a named habitat and identify examples of adaptation, competition
and interdependence
OB63 Understand the importance of conservation, pollution and waste management to the environment, and identify
ways in which living things contribute to these, both individually and as a community
OB64 Consider and discuss how human activity affects the environment, both positively and negatively (two
examples in each case)
Student Notes
Habitat Study
Ecology is the study of the interactions between organisms and their environment
A habitat is an environment where an organism lives, e.g. a hedge or a meadow
To study a local habitat
Method
1. Make a map of the habitat- mark in any distinctive physical features e.g. streams, trees, ponds, rock, paths etc.
2. Physical factors such as soil pH, temp., amount of sunlight and rainfall can be included.
3. Collect and identify plants/animals (using keys to identify various plants and animals).
Equipment used in a habitat study
Pitfall trap: collects small organisms that walk along the surface of the ground e.g. beetle, spiders, centipedes.
Beating tray: e.g. a large cloth - for insects and spiders which fall off trees and shrubs.
Pooter: for small insects, spiders, mites from surfaces of leaves and leaf litter and for transfer from
beating trays and nets into containers.
Line transect: used to show the distribution of a species across an area e.g. from shade to sun in a
woodland - use rope with knots at 1 metre - record name and height of plant touching each mark.
Quadrats
Used to measure how frequently a plant species occurs in a habitat.
Throw at random, > 10, identify and count plants as follows:
% Frequency = Number of quadrats in which ‘x’ found x 100
Total number of quadrats
6
A producer is an organism which makes its own food
Examples: plants
A consumer is an organism which feeds off other organisms
Examples: herbivores, carnivores, omnivores.
A decomposer is a living organism that feeds on dead plants and animals
Examples: bacteria and fungi.
Food Chains and Food Webs
All organisms need energy to live. Sun is the primary source of energy.
Energy flows from one organism to the next by means of a food chain.
Food Chain
A food chain is a list of organisms in the order in which one is eaten by
the other.
Example of a food chain from a forest habitat
1st
2nd
3rd
(producer)
Grass
(primary consumer)

rabbit
(secondary cons)

fox
Food Web
A food web consists of two or more interlinked food chains
Example of a food chain from a forest habitat

Adaptation, Competition and Interdependence in a food chain
Adaptation
Adaptation is the process where an organism becomes better suited to its environment
Examples of adaptation in a rabbit
1. It is brown for camouflage.
2. Long ears so it can detect the presence of its predators.
Examples of adaptation in plants
1. Some plants have a nasty taste to deter predators e.g. giant hogweed.
2. Bracken can grow in shade, grass cannot.
Competition
Competition is the struggle between organisms for a resource that is in short supply
Examples
Plants and animal compete for space, light, food, mate, water, minerals, shelter.
7
Interdependence
Interdependence is where two organisms rely on each other for some aspect of survival
Example
A plant relies on an insect for pollination while the insect relies on the plant for food.
Trees depend on birds for seed dispersal and the birds get shelter, nests, nuts and berries in return.
The size of a population depends on the availability of food and the presence or absence of other organisms
Living things are affected by their environment and respond to changes that occur in that environment
Looking after our environment; Pollution, Conservation and Waste Management
Pollution
Pollution is the process by which harmful substances are added to the environment by humans.
Examples
 Soil pollution
 Water pollution
 Air pollution
 Greenhouse effect
Conservation
Conservation is the preservation of the earth’s natural resources for the future.
Examples
 National parks
 Hedgerow and bogland conservation
 Listing of threatened species e.g. lizard, frog and stoat in Ireland
 Zoos and wildlife parks – by breeding endangered species
Waste Management
Waste management involves managing the disposal of our waste products
Examples
Reduce, Reuse, Recycle campaign
Compost bin – vegetable peelings and garden waste.
Incineration
Two negative effects of humans on the environment
1. Air pollution
2. Habitat destruction (e.g. deforestation, overhunting, etc)
Two positive effects of humans on environment
1. Protection of endangered species
2. Tree planting
8
Exam Questions
1. [2008]
The photograph of ‘spaceship earth’ was taken by a member of the crew of Apollo 17.
Give two ways in which we can care for our planet.
2. [2006]
Waste management includes: composting, incineration, landfill and recycling.
Pick one of the underlined methods of managing waste and say how it works and give
one advantage or disadvantage of using the method that you have selected.
3. [2007]
The increase in carbon dioxide concentration
in the Earth’s atmosphere is currently causing
concern. The use of fossil fuels and
deforestation have been identified as major
contributors to this increase in carbon dioxide
concentration. The graph shows a continual
increase in the carbon dioxide concentration
for the last fifty years. The data was collected
at a site in Europe.
(i) Explain how either the use of fossil fuels or
deforestation could have contributed to the increase in atmospheric carbon dioxide.
(ii) Suggest one possible effect of continued increase in carbon dioxide concentration in the Earth’s atmosphere.
(iii) Though there is an overall increase in carbon dioxide concentration there is an annual rise and fall in carbon
dioxide concentration as shown in the box in the diagram.
Suggest one reason why the carbon dioxide concentration decreases between April and October each year.
(iv) How could the reason that you have given in (iii) be used in a practical way to slow down and even reverse the
overall increase in carbon dioxide levels in the atmosphere?
4. [2009]
Give two reasons why the groups of organisms living together can vary greatly from one part of a habitat to
another.
5. [2008]
The photograph shows Amanita Phalloides, a poisonous fungus, whose common name is ‘Death
Cap’. Fungi are decomposers.
Explain the underlined term.
6. [2006]
Decomposers are living things that release useful materials, from the waste products of plants and animals and
from dead plants and animals, for reuse by living organisms. Name two kinds of decomposers found in the soil.
9
Food Chain / Food Web
7. [2009 OL]
The food chain relates to a garden habitat.
Study it and answer the questions that
follow.
(i) Name a producer in this food chain.
(ii) Name a consumer in this food chain.
(iii) Explain how the removal of ladybirds
would affect the greenfly population in
this habitat.
8. [2008]
The diagram shows part of a food web from a mixed habitat with meadows,
streams and hedges.
A is a dragonfly, B is a grasshopper, C is a butterfly
D is a house fly, E1, E2 and E3 are plants.
(i) Write down a food chain from the food web shown.
(ii) Select an organism from this habitat or name another organism from a
habitat you have studied and state one adaptation that the organism has that
makes it suited to its habitat.
(iii) What is meant by competition in a habitat?
(iv) Give an example of interdependence from the food web shown.
Equipment
9. [2008 OL]
The piece of equipment drawn on the right is used in ecology.
(i) Name the piece of equipment.
(ii) Give one use for this piece of equipment.
10. [2006 OL]
The piece of equipment drawn on the right is used in ecology.
(i) Name the piece of equipment.
(ii) Give one use of this piece of equipment.
11. [2007]
The diagram shows a pooter. It is used, when studying a habitat to collect small
animals e.g. insects, for identification. Describe how to use a pooter.
12. [2009]
The study of a habitat requires the use of sampling instruments, as it
is not possible to count every individual organism living there.
The photograph shows a pupil and teacher using a quadrat. The
quadrat is placed randomly in a number of sites in the habitat being
studied.
(i) How is random sampling achieved when using a quadrat?
(ii) Give two different types of data collected (two different tasks
performed) at each site in the habitat when using the quadrat.
13. [2009]
Line transects are also used to sample habitats.
(i) What is a line transect?
(ii) Describe how to sample a habitat using a line transect.
10
14. [2009]
The photograph shows a pupil with a sweep net.
The sweep net is used to collect small animals e.g. insects from vegetation in a
habitat so that they can be identified.
(i) Name a second item of equipment used to collect small animals for
identification.
(ii) Draw a labelled diagram, in the box provided, of the item that you have named
in (i) above.
(iii) Describe how to use the item that you have named and drawn.
Other Test Questions
1. What is ecology?
2. What is a producer? Give two examples.
3. What is a decomposer? Give two examples.
4. What is a consumer? Give two examples.
5. List a habitat which you have studied and identify a food chain and a food web from it.
6. Identify examples of adaptation, competition and interdependence from the habitat you mentioned above.
7. Why do organisms need to compete with each other?
8. What is (i) a herbivore, (ii) a carnivore, (iii) an omnivore? Give an example of each.
11
Biology: 16. Micro-organisms
Syllabus
OB65 Investigate the presence of micro-organisms in air and soil
OB66 State two uses of biotechnology in industry and two uses of biotechnology in medicine
OB67 List three common illnesses caused by viruses and three caused by bacteria.
Student Notes
Microorganisms are very small living things.
There are three types: bacteria, viruses and fungi. We do not need to look at fungi in this chapter.
Experiment: To investigate the presence of micro-organisms in air and soil
Equipment: Petri dishes with sterile nutrient agar (medium)
Add some soil to one of the petri dishes and leave another sterile as a control.
Leave both for a few days in a warm environment.
Observation: After a few days bacteria colonies can be seen in the petri dish which had soil but not in the sterile dish.
Shiny dots correspond to bacterial colonies while fluffy growth corresponds to fungi.
Biotechnology
Biotechnology is the use of living things or parts of living things to make useful products
Uses of biotechnology in industry
1. Brewing: Yeast cells get energy by converting sugar into carbon dioxide and alcohol. So the alcohol that we drink
is basically yeast poo. Think of that the next time you order a pint with your fake ID.
2. Cheese making
3. Baking
4. Yoghurt
5. Pesticides
6. Genetically modified food
7. Bio-fuel
8. Bacteria to make stain-removing enzymes in washing powders.
Uses of biotechnology in medicine
Antibiotics
Hormones (insulin)
Vaccines
Viruses
Viruses are the smallest micro-organism that can exist.
Common illnesses caused by viruses
The flu (influenza), AIDS, measles, cold sores, the common cold.
Bacteria
Bacteria are simple living cells but are larger than viruses.
Common illnesses caused by bacteria
Food poisoning, meningitis, appendicitis, pneumonia, tooth decay.
12
Exam Questions
1. [2009]
One petri dish containing agar was left covered. All of the dishes were kept warm for some days
and inspected daily.
(i) What is the function of the agar?
(ii) Why was one petri dish left covered?
(iii) Describe and explain the appearance of the agar in the exposed dishes after some time passed.
2. [2006 OL]
(i) Micro-organisms are used widely in biotechnology. Give one use of biotechnology in industry.
(ii) Micro-organisms can be found growing in a variety of locations.
Describe how the presence of micro-organisms in a sample of soil might be investigated.
Include a diagram of any equipment that might be used.
3. [2007]
The photograph shows a stage in the industrial production of cheese. This is an example
of the use of biotechnology in industry.
Give two other examples of the use of biotechnology in industry or
medicine.
4. [2008]
The photograph shows Amanita Phalloides, a poisonous fungus,
whose common name is ‘Death Cap’. Fungi are decomposers.
Explain the underlined term.
5. [2006]
Decomposers are living things that release useful materials, from the waste products of plants and animals and
from dead plants and animals, for reuse by living organisms. Name two kinds of decomposers found in the soil.
6. [2006 OL]
In ecology micro-organisms play a major role in recycling nutrients.
Name one decomposer from a habitat you have studied.
13