Genetics, populations, evolution and ecosystems

Question 1

a habitat is

Answer 1

a place where an organism lives

Question 2

a population is

Answer 2

all the organisms of one species in a habitat at the same time

Question 3

a community is

Answer 3

all the populations of different species living in the same place at the same time

Question 4

a niche is

Answer 4

role of a species within its habitat

Question 5

an ecosystem is

Answer 5

a community, plus all abiotic conditions of their environment

Question 6

carrying capacity is

Answer 6

the max stable population an ecosystem can support

Question 7

result of interspecific competition

Answer 7

reduces resources available to both, limits both populations
a better adapted species will out compete the other

Question 8

result of intraspecific competition

Answer 8

smaller population means less competition, which is better for growth and reproduction
larger populations is opposite and leads to smaller population

Question 9

result of predation

Answer 9

increased predator population, more prey eaten, prey population. falls, less food for predators, predator population size falls, prey population rises

Question 10

Randomly placed quadrats

Answer 10

-Split area into squares
-Obtain random coordinates using random number generator- place quadrats
-Count frequency of species in quadrat
-Calculate mean per quadrat
-Multiply mean by number of quadrats that would cover the area

Question 11

Quadrats along a transect

Answer 11

-Lay tape measure from one place to another
-Place quadrants at regular intervals along the line
-Count frequency in cover
-Measures change in distribution

Question 12

How to obtain valid results for capture recapture

Answer 12

-Mark must not be removed
-Mark should not affect survival/predation
-The duration of the sampling should be enough to allow mixing with the population
-NO due births
-No immigration

Question 13

Steps of succession

Answer 13

-Colonisation by pioneer species
-Pioneer species change the abiotic conditions and make the environment less hostile
-Environment becomes more suitable for other species with different adaptations, and may be less suited for previous species
-Biodiversity increases
-Climax community: final, complex, stable community with no further changes

Question 14

Conservation is

Answer 14

Protection and management of species and habitats sustainably

Question 15

Conservation techniques

Answer 15

-Plants are covered using seed banks- seeds are stored
-Fishing quotas- to conserve fish species
-Endangered species are bred in captivity

Question 16

Succession is

Answer 16

The process by which an ecosystem changes over time due to species presence.

Question 17

What is a genotype

Answer 17

Genetic constitution of an organism

Question 18

What is a phenotype

Answer 18

The expression of this genetic constitution and its interaction with the environment

Question 19

What is an allele

Answer 19

Different version of a gene

Question 20

What are forms of alleles in heterozygous state

Answer 20

-Dominant; allele that is expressed
-Recessive; allele that isn’t expressed
-Codominant; both alleles for same gene contribute to the phenotype

Question 21

What is monogenic inheritance

Answer 21

Inheritance of characteristic controlled by a single gene

Question 22

What are dihybrid crosses

Answer 22

Inheritance of two different characteristics controlled by two different genes

Question 23

Dominance hierarchy

Answer 23

There may be more that 2 alleles in a population, however individuals only have 2 alleles of a gene

Question 24

Where do sex linkages arise from and what are they

Answer 24

A gene is sex linked if its locus is on a. sex chromosome, and a specific characteristic is more likely to be inherited in either male or female offspring (genes most likely to be found on X chromosome)

Question 25

Why is it more likely that males show recessive phenotypes than females

Answer 25

Only have one X chromosome, and they often only have one allele for sex linked genes so they express the characteristic of this allele even if its recessive.
Females have two alleles and only express the recessive if its homozygous recessive

Question 26

What is an autosome

Answer 26

Non sex chromosome