Bio 30 Final review Unit D

Question 1

What is Natural selection

Answer 1

The processes through which populations of living organisms adapt and change

Question 2

What is genetic drift

Answer 2

A mechanism of evolution in which allele frequencies of a population change over generations due to chance

Question 3

What is gene flow

Answer 3

“gene migration” or “allele flow” is the transfer of genetic material from one population to another

Question 4

What is non-random mating

Answer 4

occurs when the probability that two individuals in a population will mate is not the same for all possible pairs

Question 5

What is the bottleneck effect

Answer 5

“genetic bottleneck” is a sharp reduction in the size of a population due to environmental events like natural disasters, or human activities. This reduces the genetic variation of a population

Question 6

What is the Founder effect

Answer 6

The loss of genetic variation that occurs when a population is established by a very small number of individuals from a larger population

Question 7

What is Migration and how does it affect the gene pool

Answer 7

Migration is when a population of a species moves from one populated area to another. The larger the number of migrant individuals and the greater the difference in allele frequencies the greater the effect the migrants will have on changing the genetic constitution of the resident population

Question 8

What are Mutations and what effect do they have on the gene pool

Answer 8

Mutations are a genetic defect resulting from an error in DNA replication. They are a strong force for introducing new alleles and a weak force for changing allele frequencies

Question 9

What is geographic isolation

Answer 9

This is when members of the same species are separated geographically

Question 10

What is reproductive isolation

Answer 10

This is when populations of the same species experience Drastically different changes in allele frequencies resulting in them no longer being able to reproduce

Question 11

How can geographic isolation lead to reproductive isolation

Answer 11

When populations of the same species are separated geographically, The environmental pressures of the two populations will be different. This means that natural selection will favour different traits based on the location of the population; this causes the gene frequencies of the populations to change over time. Eventually, the gene pools of the populations will change enough that members of each respective location can no longer mate.

Question 12

How do mutations result in a changing gene pool?

Answer 12

If a mutation provides a benefit, natural selection will begin to favour the mutated trait and it will become more commonplace in the gene pool.

Question 13

What are the types of competition

Answer 13

-Interspecific competition: competition between different species
intraspecific competition: competition between the same species

Question 14

What is Gause’s principle

Answer 14

Gause’s principle is founded on the idea that if two species that occupy the same ecological niche are in one ecosystem, one species will be “dominant” over the other and the less fit species will be outcompeted

Question 15

What is symbiosis and the different types

Answer 15

An interaction or “relationship” between two species

-commensalism: a biological relationship between two species in which one organism benefits and the other is neither harmed nor benefits
-Mutualism: A relationship between two species where both will benefit in some way
-Parasitism: A relationship between species where one organism, the parasite(who benefits) lives on or inside another organism(the host) and harms it in the process

Question 16

What are the Defense mechanisms

Answer 16

Mimicry: evolved resemblance to another organism or object, can involve morphological, physiological and behavioural traits
Camouflage: a tactic used to disguise their appearance, usually to blend into their surroundings. used to mask location, movement and identity
Protective toxins: some organisms are able to release and inject toxic chemicals to defend themselves from danger

Question 17

What is the difference between mimicery and camouflage

Answer 17

If an organism uses mimicry, it is trying to be perceived as something else. If an organism uses camouflage, it is trying to not be perceived at all

Question 18

What are the two kinds of succession and the difference between them

Answer 18

Primary Sucession: The changing of an environment with no life to a complex community
Secondary Sucession: the return in stages to a stable climax community in an area that’s lost its vegetation but not its soil

Question 19

What is a population

Answer 19

A group of organisms of the same species that live in the same habitat at the same time.

Question 20

What is a community

Answer 20

all organisms of various species that share a habitat at the same time

Question 21

What is an ecological niche

Answer 21

An organism’s role in an ecosystem (place in the food web, breeding area, time of day when most active)

Question 22

What are the different kinds of population distributions

Answer 22

Clumped: individuals in a population are more concentrated in certain parts of the habitat
Random: Individuals are spread throughout a habitat in an unpredictable and patternless matter
uniform: Individuals are equally spaced throughout the habitat

Question 23

What are the biotic factors that affect population growth

Answer 23

Gender ratio
Mate avalibity
gestation period
estrous period
clutch or litter size
fecundity

Question 24

What are the abiotic factors that affect population growth

Answer 24

-food supply
-availability of shelter
-water supply
-law of the minimum: growth of a population is controlled by its least available resource
-sheldfords law of tolerance: some species can only thrive in a certain range of abiotic factors
-density dependant factors
-density-independent factors

Question 25

What is a dynamic equilibrium

Answer 25

A population is in dynamic equilibrium when the number of deaths and births is the same resulting in no significant population change

Question 26

what is carrying capacity

Answer 26

Carrying capacity refers to the maximum number of individuals that can be supported by an ecosystem’s finite resources. if the carrying capacity is exceeded, competition will happen and a population crash is imminent

Question 27

What is Environmental resistance

Answer 27

The collective name given to all environmental factors that can limit a populations ability to grow

Question 28

What is the difference between open and closed populations

Answer 28

Open: a population in which change in number and density is determined by natality, immigration, mortality, and emigration
Closed: a population in which change in number and density is determined only by morality and natality

Question 29

What is exponential growth, its graph shape and the requirements for it

Answer 29

Exponential growth describes the rapid uptick in population size of a closed population, it’s characterized by a j shaped graph curve

Question 30

What is logistic growth and its graph shape

Answer 30

S-shaped graph representing normal population growth

Question 31

What are density vs density-independent factors

Answer 31

Density-dependent factors only affect dense populations of organisms such as diseases. Density-independent factors are factors that affect a population equally regardless of size like natural disasters

Question 32

What is fecundity

Answer 32

An organism’s ability to produce healthy offspring

Question 33

What is a gene pool

Answer 33

A gene pool refers to all the genes available to an individual in a particular species

Question 34

What is the Hardy-Weinberg principle

Answer 34

The Hardy-Weinberg principle states that allele and genotype frequencies in a population will remain constant and applies to populations where genotype and allele frequencies can be calculated. The factors that affect this equilibrium are: population size, migration, mutations, natural selection, non-random mating,

Question 35

How do adaptations occur as a result of natural selection?

Answer 35

Individuals who are not suited to their environment will not live to reproduce and pass on their genes. As a result over time, the population of a species will adapt to become better suited to its environment

Question 36

What is a r-selected species?

Answer 36

A species that lives in rapidly changing environments, is short-lived, has a highly varying population size, has a density-independent mortality rate, has low competition, reproduces once at a young age, does not care for its offspring, produces high numbers of offspring, has a j-shaped population curve, has a smaller body. Ex insects, salmon

Question 37

What is a K-selected species?

Answer 37

A species that lives in a stable and pridectibal environment, is often long-lived, has high competition, has density-dependent mortality, reproduces multiple times later in life, cares for young, has a lower number of offspring, has a Large body size, and has an s-shaped graph.Ex humans, elephants

Question 38

What is the difference between pioneer and climax species

Answer 38

A pioneer species is the first species to emerge after succession like moss, whereas a climax species is a more complex species supported by a fully recovered ecosystem

Question 39

What is the formula for the growth rate?

Answer 39

gr=ΔN/T

Question 40

What is the population for population density

Answer 40

Dp=N/A
Dp=N/V

Question 41

What is the formula for per capita growth rate?

Answer 41

cgr=ΔN/NO

Question 42

What are the formulas for gene and allele frequency

Answer 42

Gene frequency: p^2(AA) + 2pq(Aa)+q^2(aa)=1
Allele frequency: p(A)+q(a)=1

Question 43

What is the difference between gene and allele frequency

Answer 43

Gene frequency is a measure of the genotypes and allele frequency is a measure of the rarity of alleles within a populations gene pool