Genetics, Populations, Evolution And Ecosystems

Question 1

Define genotype

Answer 1

An organisms genetic composition

Question 2

Define phenotype

Answer 2

An organisms characteristics, which occurs as a result of both its genotype and the impact of the environment

Question 3

What is an allele?

Answer 3

Alternative forms of a particular gene with different base sequences and therefore different codes

Question 4

What are the four types of alleles?

Answer 4

Dominant
Recessive
Co-dominant
Multiple alleles

Question 5

What is the difference between diploid and haploid cells?

Answer 5

Haploid cells contain only one set of chromosomes (half set -23) and diploid cells chromosomes occur in pairs (full set -46)

Question 6

What are heterozygous cells?

Answer 6

Organisms in which paired alleles are different
E.G- Bb

Question 7

What are homozygous cells?

Answer 7

Organisms in which paired alleles are the same.
E.G- BB or bb

Question 8

Define monohybrid inheritance

Answer 8

Inheritance of a single pair of alleles- only one from each gamete (due to meiosis)

Question 9

Define dihybrid inheritance

Answer 9

Inheritance of two different characteristics simultaneously

Question 10

What is an autosome?

Answer 10

Chromosomes numbered (1-22) which are known as body cells not sex cells

Question 11

State the difference between sex-linkage and autosomal linkage

Answer 11

Sex linkage occurs when there is a gene on the X chromosome, not present on the Y chromosome.
Whereas autosomal linkage occurs if two or more genes are located on the same autosome(non-sex chromosomes)

Question 12

What is a species?

Answer 12

A group of organisms that can successfully interbreed

Question 13

Define population

Answer 13

Members of the same species living in one habitat

Question 14

Define gene pool

Answer 14

Complete range of alleles in a population

Question 15

Define allele frequency

Answer 15

Relative frequency of a particular allele in a population

Question 16

What is the hardy-Weinberg principle?

Question 17

Explain the hardy-Weinberg equation for calculating allele frequency

Question 18

Explain the hardy-weinberg equation to calculating genotype frequency

Question 19

What are the conditions under which the Hardy- Weinberg principle equation applies?

Question 20

What two factors affect variation?

Question 21

What is the primary source of genetic variation?

Question 22

What is natural selection?

Question 23

What is stabilising selection?

Question 24

What is directional selection?

Question 25

What is disruptive selection?

Question 26

What is evolution?

Question 27

Define genetic drift

Question 28

Now does natural selection cause a change in a populations gene pool?

Question 29

Why does genetic drift affect smaller populations more than larger ones?

Question 30

Define community

Question 31

Define ecosystem

Question 32

Define biotic and give examples

Question 33

Define abiotic and give examples

Question 34

Define niche

Question 35

Define habitat

Question 36

What is meant by 'carrying capacity’?

Question 37

List four abiotic factors that affect population growth

Question 38

What is meant by intraspecific and interspecific competition?

Question 39

What are the two ways in which size of a population can be estimated?

Question 40

How can quadrants be used for estimating population size?

Question 41

How is mark-release- recapture used for estimating population size?

Question 42

What is the equation for mark -release -recapture?

Question 43

What are the assumptions made by the mark-release-recapture method?

Question 44

Why are ecosystem described as being ‘dynamic'?

Question 45

What is primary succession?

Question 46

Summarise the process of primary succession

Question 47

Define conservation

Question 48

How might succession be managed in order to help conservation?

Question 49

What is a dominant allele?

Question 50

What is a recessive allele?

Question 51

What are co-dominant alleles?