Unit D Test

Question 1

What is dynamic equilibrium?

Answer 1

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

Question 2

What are density-dependent factors and density-independent factors

Answer 2

Density-dependent factors are factors that 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 3

What is carrying capacity

Answer 3

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 4

Define fecundity

Answer 4

An organisms ability to produce healthy offspring

Question 5

Define non-random mating

Answer 5

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

Question 6

Define natural selection

Answer 6

The processes through which populations of living organisms adapt and change

Question 7

Define gene pool

Answer 7

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

Question 8

Define environmental resistance

Answer 8

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

Question 9

What is migration

Answer 9

The greater the difference in allele frequencies between the resident and the migrant individual, and the greater the number of migrants, the greater the effect the migrants will have in changing the genetic constitution of the resident population

Question 10

What is geographic isolation

Answer 10

When members of the same species are separated geographically

Question 11

What is Gause’s principle?

Answer 11

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 12

How do adaptations occur as a result of natural selection?

Answer 12

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 13

What is symbiosis and what are the three types

Answer 13

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 14

What are the two types of competition and their definitions?

Answer 14

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

Question 15

What is the difference between mimicry and camouflage

Answer 15

Mimicry: Mimicry is an evolved resemblance between an organism and another object, often an organism of another species. This may involve morphological, physical or behavioural traits

Camouflage: A defence mechanism or tactic that organisms use to disguise their appearance, usually to blend in with their surroundings. Organisms use camouflage to mask their location, identity and movement.

Mimicry is a species attempting to pass as another species or object, whereas camouflage is a species attempting to better blend in with their surroundings

Question 16

What shape will the graph of exponential growth be

Answer 16

J shaped: Rapid increase with no limiting factors

Question 17

What shape will the graph of logistical growth be

Answer 17

S curve: lag phase (reproduction is low), growth phase(growth rate spikes), stationary phase(population has reached its carrying capacity and levelled out)

Question 18

What is a r-selected species

Answer 18

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 19

What is a K-selected species

Answer 19

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, lower number of offspring, has a Large body size, and has an s-shaped graph.Ex humans, elephants

Question 20

What is the difference between primary and secondary succession

Answer 20

Primary succession: The changing of an environment from bare rock(no soil) to a complex community( multiple plant/animal species)

Secondary succession: The return of life to an area that has lost its vegetation

Question 21

What is the difference between pioneer and climax species

Answer 21

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 22

What is the formula for growth rate

Answer 22

gr=ΔN/T

Question 23

What is the population for population density

Answer 23

Dp=N/A
Dp=N/V

Question 24

What is the formula for per capita growth rate

Answer 24

cgr=ΔN/NO

Question 25

What five conditions impact the Hardy-Weinberg genetic equilibrium

Answer 25

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 26

What are the formulas for gene and allele frequency

Answer 26

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

Question 27

What is the difference between gene and allele frequency

Answer 27

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