Download A period Final Exam Review

A period Final Exam Review
Ecology
Ecology: The scientific study of the interactions of organisms with their environments (includes
biotic and abiotic factors.
 ecology is the branch of biology that deals with the relations of organisms to one
another and to their physical surroundings.
Biosphere: Contains the combined portions of the planet in which all of life exists including:
1.Land
2.Water
3.Air/Atmosphere
Biotic factors: Living things in an environment (Parasites, predators)
Abiotic factors: Nonliving things in an environment (Climate, fires, sunlight, water)
Factors that affect life in the Biosphere
1.Energy source: Sunlight, chemicals(inorganic), food(organic)
2.Temperature: Affect metabolism
3.Water: How much is needed depends on the organism
4.Nutrients: Nitrogen, Phosphorus
5.Other aquatic factors: Dissolved oxygen, tides, salinity, current
6.Other terrestrial factors: Wind, fire
Levels of Organization
1.Species: Individual living thing
2.Populations: Groups of organisms of the same species in the same area
3.Communities: Many populations or organisms living close enough for interaction
4.Ecosystem: Includes biotic and abiotic factors in the environment
5.Biome: Group of ecosystems that have the same climate
6.Biosphere: All of Earth
Energy Flow in the Biosphere
Without a constant input of energy, living systems cannot function. Sunlight is the main energy
source for life on Earth. Some types of organisms rely on the energy stored in inorganic
chemical compounds.
Autotroph: Organisms that can capture energy from sunlight or chemicals and use that energy
to produce food (primary producers)
Photosynthesis: Autotrophs use light energy to convert carbon dioxide and water into oxygen
and energy rich carbohydrates
Some autotrophs can produce food in the absence of light:
Chemosynthesis: When organisms use chemical energy to produce carbohydrates
Heterotrophs: Organisms that rely on other organisms for their energy and food
supply(consumers)
Herbivores: Eat plants, leaves, fruit
Carnivores: Eat/kill other animals
Omnivores: Eat both plants/animals
Detritivores: Feed on detritus, small pieces of dead, decaying animals/plants
Decomposers: Like bacteria and fungi, break down organic matter, produce detritus
Food chain: Series of steps in which organisms transfer energy by eating and being eaten
Food web: Links all the food chains in an ecosystem together
Trophic level: Each step in a food chain or web
Producers make up the 1st trophic level
Consumers make up the 2nd, 3rd, or higher trophic level
Ecological Pyramid: A diagram that shows the relative amounts of energy or matter contained
within each trophic level in a food chain or web
How Populations Grow
1.Population density: Number of individuals per unit area
2.Geographic distribution/range: Area inhabited by a population
3.Growth rate: Determines if the population is increasing, decreasing, or staying the
same
4.Age structure: The number of males/females of each age a population contains
Factors that can affect population size
1. Number of births
2. Number of deaths
3. Number of individuals that enter/leave the population
Immigration: The movement of individuals into an area
Emigration: The movement of individuals out of an area
Exponential growth: Occurs when the individuals in a population reproduce at a constant rate
Logistic growth: Occurs when a population's growth slows or stops following a period of
exponential growth
Exponential Growth
Logistic Growth
The two types of succession:
Primary succession and secondary succession
Primary succession- no soil to start with. Over 115+ years and every will be back to the way it
was
Secondary succession- occurs faster than primary succession because the soil would have
survived after disturbance striving vegetation regrows rapidly.
Ecological relationships
Predation- one organisms kills and harm another
Commensalism- a relationship between individuals of two species in which one species obtains
food or other benefits from the other without either harming or benefiting the latter.
Mutualism- A mutualistic relationship is when two organisms of different species "work
together," each benefiting from the relationship. One example of a mutualistic relationship is
that of the oxpecker (a kind of bird) and the rhinoceros or zebra.
Parasitism- Parasitism is a non-mutual symbiotic relationship between species, where one
species, the parasite, benefits at the expense of the other, the host.
Evolution Review
Central concepts: Evolution is the result of genetic changes that occur in
constantly changing environments. Over many generations, changes in the the
genetic makeup of population may affect biodiversity through speciation and
extinction
Lyell
Lamarck
explained how geological features are built up/torn down over long periods of time
proposed the idea of USE and DISUSE of organs. By USING or NOT USING
organs, an organism would acquire or lose them in their lifetime. These traits
would then be passed on to their offspring. Over time, this led to change in a
species.
Malthus eventually there would not be enough resources for that species to survive.Forces
that work against growth are war, famine and disease
Darwin
This hypothesis led to the theory of evolution, also known as natural selection1.animals struggle for existence 2. fit animals survive 3. organisms descend with
modifications
Malthus believed that three things work against the growth of a populationFamine,War,Disease
5.1- Fossils are preserved remains or traces of ancient organisms. Fossils provide a
time period on when the organism lived. By comparing fossils from older rock layers with
younger rock layers you can see the change of Earth over time.
5.3- organisms will evolve through natural selection because as they travel to
different regions and become separated from other parts of the same species, then
they will slowly evolve certain things to help them survive in the given ecosystem.
eventually they will be separated and have the same descendents but will look
completely different and become different species. with different species being
created, it will create more variety throughout the world and in ecosystems.
Genes and variations
Mutations- any change in the dna sequence
Gene Shuffling- occurs during the production of gametes
Single gene trait- controlled by single gene with two alleles
Polygenic traits- trait controlled by 2 or more genes
Types of Natural selection graphs
1. Directional Selection- when individuals at one end of the curve have a higher fitness
than individuals in the middle or at the end
2. Disruptive Selection--when individuals at the upper and lower end of the curve have
higher fitness than individuals near the middle
3. Stabilizing Selection- when individuals near the center of the curve have higher
fitness than individuals at either end of the curve
Hardy-Weinberg Principle- five conditions are required to maintain genetic
equilibrium from generation to generation
1. random mating
2. population must be very large
3. no movement into or out of a population
4. no mutation
5. no natural selection
Types of isolation- Gene pools of two populations must become separated for
them to become new species
1. reproductive isolation- when members of two populations cannot
interbreed and produce fertile offspring.
2. behavioral isolation- when two populations are capable of interbreeding but
have differences in courtship or other types of behavior.
3. geographic isolation- when two populations are separated by geographical
barriers.
4. temporal isolation- When two or more species reproduce at different times.
Genetics
Words to know:
 True- breeding: organisms that always pass down a certain trait to
offspring
 Trait: a specific characteristic that varies from one individual to
another
 Hybrid: offspring crossed between two parents with different traits
 Gene: basic physical and functional unit of heredity
 Allel: visible DNA
 Segregation: separating a pair of alleles at meiosis
 Gamete: sex cells
Gregor Mendel Mendel was an austrian monk who studied the inheritance of traits in
pea plants
 he developed the laws of inheritance
 he found that the plant's offspring retained traits of the parents
His theory
Mendel had true-breeding pea plants that allowed to self pollinate, would
produce an identical offspring to themself. Mendel wanted to be able to
control variables and cross-pollinate: he would use two different parents for
pollination to produce a seed.
Each original pair of plants is the: P (parental)generation
The offspring are called: F1 generation
The offspring of crosses between parents with different traits are: hybrids
Mendel's first conclusion: the inheritance is determined by the factors that
are passed from one generation to the next
Today traits are considered your chromosomes
Each of the traits mendel studied was controlled by one gene that occurred
in two contrasting forms that produced different characters for each traitdifferent forms of genes are called: alleles
Mendel’s second conclusion: the principle of dominance: that states that
some alleles are dominant and others are recessive
Example:
More words to know:
 Probability: the likelihood something will happen
 Punnett square: a diagram that is used to predict an outcome of a
particular cross or breeding
 Homozygous: genotype that has two identical alleles
 Heterozygous: genotype that has two nonidentical alleles
 Phenotype: an organism's observable characteristics or traits
 Genotype: the genetic makeup of a cell, and organism, or an
individual
Punnett Squares:
can be used to predict and compare the genetic variation that will result
from a cross
Example:
Capital letter: dominate
Lower case letter: recessive
Organisms that have two identical alleles particular traits are homozygous
Organisms that have two different alleles for the same trait are
heterozygous
Heterozygous= dominant trait
Homozygous organisms are true-breeding for a trait
Heterozygous organisms are hybrids for a particular trait
Depending on the number alleles there could be a 2x2 box or a 4x4 box
Summary of Mendel’s principles
1. the inheritance of biological characteristics is determined by individual
unit called genes(segments of DNA), which are passed from parents
to offsprings
2. Where two or more forms (alleles) of the gene for a single trait exist,
some alleles may be dominate others recessive
3. IN most sexually reproducing organisms each adult has two copies of
each gene- one from each parent, these genes segregate from each
other when gametes are formed
4. alleles for different genes usually segregate independently of each
other
Incomplete dominance: when one allele is not completely dominant over
another.
Example: red flowers crossed with white flowers produce pink flowers
Codominance: both alleles are going to contribute to the phenotype
Example: heterozygous chickens are speckled with both black and white
feathers
Multiple alleles: genes that are controlled by more than two alleles
Example: a rabbit's coat color is determined by a single gene with 4
different alleles
Polygenic traits: traits controlled by two or more genes
Example: skin color
Genetics Study guide
vocab
Genetics
Scientific study of heredity
True- breeding
Produced offspring identical to itself
trait
specific characteristics of individuals
Hybrid
offspring of crosses between parents with different traits
Gene
sequence of DNA that code for a protein and thus determine a trait
Allele
one of a number of different forms of a gene
Segregation
separation of cells
gamete
sex cells
Gregor Mendel
1. studied the inheritance of traits in a pea plant he developed the laws of inheritance
Mendel's first conclusion
1. inheritance is determined by factors that are passed from one generation to the next
(genes)
Each trait Mendel studied was controlled by one gene that occurred in two contrasting forms
that produced different characters for each trait. the different forms of genes are called alleles
ex) freckles or no freckles
Mendel's second conclusion (principle of dominance)
1. the principle of dominance states that some alleles are dominant & others are recessive
Segregation
the reappearance of a trait controlled by the recessive allele indicates that at some point
the allele for shortness has been segregated from the allele.
Genetics and probability
vocab
probability
likelihood that a particular event will occur
punnett
square
diagram that can be used to predict the genotype and phenotype
combinations of genetic cross
homozygous
having two identical alleles for a particular gene
heterozygous
having two different alleles for a particular gene
phenotype
physical characteristics of an organism
the laws of probability can be used to predict the outcome of a genetic crosses
Punnett squares
1.
2.
3.
4.
5.
a capital letter represents the dominant allele
a lower case letter represents the recessive allele
if an organism is heterozygous, that means that they will show the dominant trait
homozygous organisms are True-breeding for a trait
heterozygous organisms are hybrid for a particular trait
Summary of Mendel’s principles
1. the inheritance of biological characteristics is determined by individuals units
called genes which are passed down from parent to offspring
2. where 2 or more (alleles) of the gene for a single trait exists, some alleles may be
dominate others may be recessive
3. in most sexualt reproduction organisms, each adult has 2 copies for each gene.
theses genes segregate from each other when gametes are formed
4. alleles for different genes usually segregate independently of each other
Vocab.
definition
example
when one allele is not
completely dominant over
another
red flowers cross with white
flowers. the flowers will produce
pink flowers
word
Incomplete
Dominance
Codominance
both alleles contribute to the
phenotype
Heterozygous chicken are
speckled with both black and
white feathers
Multiple alleles
Genes that are controlled by
more than two alleles are said
to have multiple alleles
a rabbit's coat colors is
determined by a single gene that
has at least four different alleles
polygenic trait
Traits controlled by two or
more genes
skin color