Key Area 4: Variation and Inheritance

Question 1

Combining genes from two parents contribute to

Answer 1

Variation within a species

Question 2

When one gene controls a characteristic?

Answer 2

It produces a different number of different phenotypes

Question 3

A discrete variation is where

Answer 3

Measurements fall into distinct groups

Question 4

A discrete variation is usually represented on?

Answer 4

Bar charts

Question 5

Most features on individual phenotypes are?

Answer 5

Polygenic (controlled by many genes) and show continuous variation

Question 6

Continuous variation shows a range of values between a

Answer 6

Minium and a maximum

Question 7

Continuous variation is usually represented on?

Answer 7

Histograms

Question 8

Discrete variation are characteristics that

Answer 8

Characteristics controlled by a single gene (one copy inherited from each parent) tend to have phenotypes that fall into separate categories

Question 9

A phenotype is an

Answer 9

an individual’s observable traits, such as height, eye color and blood type

Question 10

Genotype is

Answer 10

a statement of the alleles it has for a characteristic

Question 11

The final appearance of an organism (phenotype) is the result of?

Answer 11

It’s genes (genotype) and the effect of the environment

Question 12

If organisms form identical genotypes are subject to different environmental condition they can?

Answer 12

Show considerable variation

Question 13

Environmentally influenced changes have minor

Answer 13

Evolutionary significance as they are not passed from one generation to another

Question 14

Gene is

Answer 14

A strand of DNA coding for a protein

Question 15

A gene will

Answer 15

Affect the organisms appearance

Question 16

Allele is

Answer 16

The forms a gene can take

eg. Pea height gene has alleles for tall and dwarf

Question 17

Dominant alleles will?

Answer 17

Always show in the phenotype, it hide other allele(s) of the same gene

Question 18

Recessive alleles are

Answer 18

Hidden by the dominant allele

Question 19

The genotype is

Answer 19

The list of actual alleles present in an organism

Eg. AA or aa

Question 20

Homozygous are?

Answer 20

Alleles that are the same

Eg. AA or aa

Question 21

Heterozygous are

Answer 21

Alleles that are different

Eg. Aa or Bb

Question 22

Phenotype is

Answer 22

The visible/detectable effect of the genotype

Eg. Tall or dwarf peas

an individual’s observable traits, such as height, eye color and blood type

Question 23

The parental genotypes is the?

Answer 23

P generation

Question 24

You can work out the p generations offspring by reading questions carefully. The offspring are referred to as

Answer 24

The F1 generation

Question 25

The grandchildren or offspring of F1 are referred to as the

Answer 25

F2 generation

Question 26

The crosses can be worked out using a

Answer 26

Punett square

Question 27

The predicted phenotype ratio among offspring are not always

Answer 27

Achieved

Question 28

The ratio is not always achieved because fertilisation is

Answer 28

A random process

Question 29

polygenic inheritance?

Answer 29

where a characteristic is controlled by more than one gene

Question 30

Most features of an individual pheotype are?

Answer 30

Polygenic and show continuous variation

Question 31

Discrete variation is?

Answer 31

when a characteristic can only fall into a certain number of distinct categories, with no intermediate forms. eg. You either have detached earlobes or attached ones.

Question 32

Continuous variation is?

Answer 32

Continuous variation is a gradual change in a characteristic across a population. For example, a person's height is a continuous variation because it can be any value between the shortest and tallest person in the world