AO1 - Unit 7

Question 1

Define genotype

Answer 1

the genetic constitution of an organism

Question 2

What is phenotype?

Answer 2

the expression of genotype and its interaction with the environment

Question 3

Define allele

Answer 3

an alternative form/version of a gene

Question 4

What is a length of DNA that codes for a polypeptide?

Answer 4

a gene

Question 5

What is meant by dominant?

Answer 5

An allele which if present will show itself in the phenotype

Question 6

What is meant by recessive?

Answer 6

An allele that will only show itself in the phenotype if there i9s no dominant allele present. For recessive chgaracteristic to be seen organism must haved 2 copies of the recessive allele

Question 7

What is codominance?

Answer 7

A situation where neither allele is recessive; so if both present in genotype, both are expressed in phenotype

Question 8

What is meant when an organism is described as heterozygous?

Answer 8

It possesses two different alleles e.g. Tt

Question 9

What is meant when an organism is described as homozygous?

Answer 9

Possesses two alleles that are the same e.g. AA or aa. Often described as true/pure breeding

Question 10

What is meant by locus?

Answer 10

Position of a gene/allele on a chromosome

Question 11

What is used to predict the possible outcomes of a genetic cross?

Answer 11

Punnett Square

Question 12

What occurs when 1 gene’s allele masks the phenotypic effects of another gene’s allele?

Answer 12

Epistasis

Question 13

What statistical test would be used to compare observed phenotypic values with expected ratios?

Answer 13

Chi squared

Question 14

The property of genes being inherited together with other genes located on the same chromosome is?

Answer 14

linkage

Question 15

How is a gene described when it is active and making a particular protein/polypeptide?

Answer 15

expressed

Question 16

Any chromosome that is not a sex-determining chromosome is called an ____________

Answer 16

Autosome

Question 17

A dihybrid cross involves how many genes?

Answer 17

2

Question 18

How many copies of each gene in a diploid cell?

Answer 18

2- one from each parent

Question 19

What sex chromosomes are found in a female mammal?

Answer 19

X

Question 20

What sex chromosomes are found in a male mammal?

Answer 20

X and Y

Question 21

Define the term population

Answer 21

A group of organisms of the same species occupying a particular space at a particular time that can potentially interbreed

Question 22

What does the Hardy Weinberg principle predict?

Answer 22

That allele frequencies in a population will remain constant from one generation to the next

Question 23

What conditions must be satisfied for HW to operate?

Answer 23

Random mating/no mutations/ no selection/large population/ no immigration;emigration

Question 24

What are the 4 key features of Darwin?s theory of natural selection?

Answer 24

Always variation/ always competition for resources/those individuals with favourable alleles will have selective advantage- these will survive and reproduce- passing on favourable allele-/allele frequency changes

Question 25

Give 3 types of adaptation to the environment.

Answer 25

Anatomical/physiological/behavioural

Question 26

Give the 2 Hardy Weinberg equations used to calculate allele frequency

Answer 26

p+ q = 1 p2+2pq+q2= 1

Question 27

Name 3 types of selection

Answer 27

Stabilising/ directional/ disruptive

Question 28

What is the primary source of variation?

Answer 28

mutation

Question 29

During sexual reproduction what are the processes that add to genetic variation?

Answer 29

Meiosis/ random fusion of gametes

Question 30

The sum total of the alleles circulating in the interbreeding population is the ___________

Answer 30

gene pool

Question 31

The process of forming new species from existing species is ___________

Answer 31

Speciation

Question 32

What is the type of speciation in which a new species develops when physically separated from the original population?

Answer 32

Allopatric speciation

Question 33

A type of speciation where isolation takes place even though the 2 populations live together.

Answer 33

Sympatric speciation

Question 34

What can members of the same species do?

Answer 34

reproduce successfully- to produce fertile offspring

Question 35

The effects of genetic drift are greater in small or large populations?

Answer 35

Small-as genetic diversity is less/smaller variety of alleles- they do not have an equal chance of being passed on.enables speciation to occur more rapidly

Question 36

What is a community?

Answer 36

All of the organisms of all species in the ecosystem

Question 37

What is an ecosystem?

Answer 37

A natural unit consisting of producers, consumers and decomposers together with the non-living components

Question 38

Define niche.

Answer 38

A concept that explains an organisms place and role within the ecosytem

Question 39

What does the "competitive exclusion principle" state?

Answer 39

It sates that no 2 organisms can occupy the same niche- this means they do not compete for the same resources

Question 40

What are abiotic factors?

Answer 40

Physical/environmental factors

Question 41

Suggest 2 biotic factors.

Answer 41

Competition/predation

Question 42

Competition between individuals of different species is called?

Answer 42

interspecific

Question 43

Competition between members of the same species is called?

Answer 43

Intraspecific

Question 44

How would you estimate the population of non-motile organisms?

Answer 44

Random quadrats

Question 45

How would you estimate the population of motile organisms?

Answer 45

mark release recapture

Question 46

How would you investigate the distribution of organisms?

Answer 46

belt/line transect

Question 47

What assumptions are made when using the MRR technique?

Answer 47

large population/no immigration;emigration/ stable population- no births;deaths/ marking has no effect/marked individual have time to reintegrate themselves

Question 48

How can population be estimated using MRR?

Answer 48

population = MxC/R where M= number captured and marked on 1st visit, C is total number captured on second visit, R is number marked in second sample

Question 49

What is succession?

Answer 49

The development sequence of an ecosystem.

Question 50

What are pioneer species?

Answer 50

species that initially colonise an ecosystem

Question 51

During succession what changes at each stage?

Answer 51

The conditions are made less hostile e.g. deeper richer soil

Question 52

What is the final stage of succession?

Answer 52

The climax community

Question 53

What is biodiversity a measure of?

Answer 53

the number of species living living in a certain area

Question 54

Conservation of habitats frequently involves what?

Answer 54

managing succession

Question 55

Human needs have to be managed to maintain the sustainability of?

Answer 55

Natural resources