Unit D

Question 1

allele frequency

Answer 1

proportion of each allele in a populations gene pool

Question 2

evolution

Answer 2

the change in genetics over time, not the change in traits in an individuals lifetime.

Question 3

gene pool

Answer 3

total of all alleles in a population

Question 4

Hardy-weinberg equilibrium

Answer 4

describes a population in which allele frequencies do not change over time. no microevolution is happening

Question 5

Hardy-Weinberg Principle

Answer 5

allele frequencies in a gene pool will remain at equilibrium in each generation of a sexually reproducing population if 5 of the following conditions are met:
1. No selection
2. No mutation
3. No migration
4. No small populations
5. Random mating

Question 6

microevolution

Answer 6

the change in allele frequencies in a population over time

Question 7

p+q=1

Answer 7

sum of allele frequencies in a population for any gene of any diploid organism.

Question 8

p^2 + 2pq + q^2 = 1

Answer 8

equation used to describe genotypic frequencies

Question 9

population

Answer 9

all members of one species occupying a particular area at the same time and that interbreed

Question 10

Bottleneck effect

Answer 10

extreme example of genetic drift that happens when the size of a population is severely reduced (natural disasters, etc)

Question 11

directional selection

Answer 11

type of natural selection where one extreme phenotype is favoured, causing the average trait in a population to shift in one direction over time.

Question 12

disruptive selection

Answer 12

type of natural selection where 2 or more extreme phenotypes are favoured. 2 or more different habitats

Question 13

founder effect

Answer 13

occurs when a few individuals form a new colony and their collective genes represent only a fraction of the original gene pool

Question 14

gene flow

Answer 14

the movement of alleles between populations
- individuals migrate from one population to another

Question 15

genetic drift

Answer 15

occurs when populations are drastically reduced in size.

Question 16

heterozygote advantage

Answer 16

only alleles that are expressed are subject to natural selection. the heterozygote is a potential protector of recessive alleles

Question 17

mutation

Answer 17

genetic changes that are the only source of new variation in a population

Question 18

natural selection

Answer 18

process that allows some individuals with an advantage over others to survive and produce more offspring. it acts on phenotypes and results in adaptation

Question 19

nonrandom mating

Answer 19

occurs when individuals are selective about choosing a mate.

Question 20

stabilizing selection

Answer 20

extreme phenotypes are selected against. a constant environment

Question 21

biosphere

Answer 21

the portion of the earth where living organisms exist

Question 22

community

Answer 22

consists of all the various populations at a particular location

Question 23

ecology

Answer 23

The study of the interactions of organisms with each other and with their physical environment

Question 24

ecosystem

Answer 24

encompasses a community of populations, as well as the nonliving environment

Question 25

extrinsic factors

Answer 25

External environmental influences. Predation Climate/weather Food/water availability Habitat loss Natural disasters

Question 26

intrinsic factors

Answer 26

Internal, biological factors affecting a population. Reproductive rate Genetic diversity Intraspecific competition Social behavior Age structure

Question 27

population (N)

Answer 27

all organisms of the same species interacting with the environment in a particular

Question 28

population density (Dp)

Answer 28

the number of individuals of a species per unit area or volume

Question 29

biotic potential

Answer 29

the highest possible per capita rate of increase for a population

Question 30

carrying capacity

Answer 30

the number of individuals of a species that a given environment can support

Question 31

exponential growth

Answer 31

📈 Exponential Growth (Ecology) A rapid population increase under ideal, unlimited conditions. J-shaped curve Resources are abundant Birth rate > death rate No limiting factors (temporarily)

Question 32

growth rate (gr)

Answer 32

describes how quickly a population is increasing or decreasing

Question 33

lag phase

Answer 33

growth is slow because of a small population

Question 34

logistic growth

Answer 34

The amount of environmental resistance increases as the population grows. This eventually causes population growth to level off, resulting in logistic growth, an S-shaped curve with four phases: 1. Lag phase 2. exponential growth phasee 3. logistic growth phase 4. stable equilibrium phase

Question 35

per capita growth rate (cgr)

Answer 35

represents the change in population relative to the initial population size

Question 36

population change (N)

Answer 36

∆𝑁 = 𝑛𝑎𝑡𝑎𝑙𝑖𝑡𝑦 + 𝑖𝑚𝑚𝑖𝑔𝑟𝑎𝑡𝑖𝑜𝑛 − 𝑚𝑜𝑟𝑡𝑎𝑙𝑖𝑡𝑦 + 𝑒𝑚𝑖𝑔𝑟𝑎𝑡𝑖𝑜𝑛

Question 37

stable equilibrium

Answer 37

Little growth occurs because births and deaths are equal.

Question 38

abiotic

Answer 38

non living factors like weather and environmental change

Question 39

Batesian mimicry

Answer 39

a prey that is not harmful mimics another species that has a successful antipredator defence

Question 40

biotic

Answer 40

living factors. competition, predation, parasitism, etc.

Question 41

commensalism

Answer 41

One species benefits; the other is neither benefited nor harmed. One species may provide a home or transportation for the other.

Question 42

competition

Answer 42

Competition occurs when members of two species try to use the same limited resource.

Question 43

competitive exclusion

Answer 43

No two species can occupy the same ecological niche at the same time if resources are limited. * One species will eventually out-compete the other.

Question 44

density-dependent

Answer 44

* Effects depend on the size of the population * Biotic factors (competition, predation, parasitism, etc.)

Question 45

density-independent

Answer 45

* Effects are the same for all sizes of populations * Abiotic factors (weather, natural disasters, etc.)

Question 46

ecological niche

Answer 46

An ecological niche is the role a species plays in the community.

Question 47

host

Answer 47

A parasite derives nourishment from another organism called the host.

Question 48

K-strategist

Answer 48

equilibrium pattern Usually, K-strategists exhibit the following traits: * Large in size * Slow to mature * Long life span * Few large offspring * Parental care * Populations tend remain at carrying capacity * Specialists (more vulnerable to extinction) Examples include birds and mammals.

Question 49

Müllerian mimicry

Answer 49

species resemble each other and share the same successful defences

Question 50

mutualism

Answer 50

Both species benefit, although the degree of benefit may not be equal.

Question 51

parasitism

Answer 51

A parasite derives nourishment from another organism called the host. The parasite benefits, and the host is harmed.

Question 52

predation

Answer 52

Predation occurs when one organism, the predator, feeds on another, the prey.

Question 53

resource partitioning

Answer 53

Feeding niches may be divided between species. * Decreases interspecific competition, thereby allowing survival via occupancy of different niches.

Question 54

r-strategist

Answer 54

opportunistic pattern Usually, r-strategists exhibit the following traits: * Small in size * Mature early * Short life span * Many small offspring * Little or no parental care * Populations tend to grow quickly * Generalists (not as vulnerable to extinction) Examples include weeds and insects.

Question 55

symbiosis

Answer 55

Symbiosis refers to close interactions between members of different species.

Question 56

climax-pattern model

Answer 56

particular areas will always lead to specific climax communities. * Based on the fact that climate helps determine whether a desert, a grassland, or a forest results.

Question 57

facilitation model

Answer 57

each community prepares the environment for the next. * Grasses are necessary before shrubs, and then shrubs before trees. It is a sequential process.

Question 58

inhibition model

Answer 58

the colonizing species stays until they die or are damaged. * The colonizing species makes the area less hospitable for new successive species.

Question 59

pioneer species

Answer 59

first to begin process of succession

Question 60

primary succession

Answer 60

Primary Succession: Establishment of a plant community in a newly formed area lacking soil. * This could be due to a major disturbance, such as a volcanic eruption or glacial retreat

Question 61

secondary succession

Answer 61

Secondary Succession: Return of a community to its natural vegetation following a disturbance.

Question 62

tolerance model

Answer 62

different plant types can colonize at the same time. * Random chance determines which arrives first.