Variation

Question 1

What is a species?

Answer 1

it a group of organisms that are capable of interbreeding to produce fertilities offspring

Question 2

What is variation?

Answer 2

there are differences between members of the same species

Question 3

What are the two types of variation?

Answer 3

• acquired variation

- inherited variation

Question 4

What is acquired variation?

Answer 4

variations that are not inherited but learn

Question 5

What is inherited variation?

Answer 5

variations that are controlled by genes

Question 6

Give an example of acquired variation

Answer 6

knowing how to ride a bike

Question 7

Give an example of inherited variation

Answer 7

having freckles

Question 8

What are the two causes of inherited variation?

Answer 8

sexual reproduction

mutation

Question 9

What are the 3 reasons that sexual reproduction causes genetic variation?

Answer 9

• independent assortment of chromosome at gametes formation during meiosis
• random fertilisation of an egg and sperm ensure no two offspring are the same
• during meiosis a process called crossing over occurs. this allows genes to be exchanged between chromosomes

Question 10

What is the crossing over process?

Answer 10

during meiosis it allows genes to be exchanged between chromosomes

Question 11

When does crossing over occur?

Answer 11

meiosis

Question 12

What is mutation?

Answer 12

a spontaneous change in the number or structure of DNA cause by mutagens

Question 13

What happens to mutations in a gamete?

Answer 13

they are passed on to the next generation

Question 14

What happens to mutations in somatic (body) cells?

Answer 14

they are not passed onto the next generation

Question 15

What may mutations produce?

Answer 15

new alleles, beneficial phenotypes, benign and maligned tumours, genetic defects in offsprings

Question 16

What is the significance of inherited variation in evolution?

Answer 16

mutation is a major method by which new genetic information enters a species. it produces new genotypes and allows natural selection to pick the favourable genotypes and better adapted population evolves

Question 17

What is a mutagen?

Answer 17

an agent that causes mutations

Question 18

Give 3 examples a mutagens

Answer 18

• radiation (X-rays )
• chemicals(cigarette smoke)
• viruses

Question 19

What are the two types of mutation?

Answer 19

gene (point) mutation

chromosome mutation

Question 20

What is gene(or point) mutation?

Answer 20

it is a change in a single gene

Question 21

What is chromosome mutation?

Answer 21

it is the change in number or structure of one or more chromosomes

Question 22

Name and explain an example of gene mutation

Answer 22

sickle cell anaemia

Question 23

Name and explain an example of chromosome mutation

Answer 23

Down syndrome

Question 24

What is classification?

Answer 24

placing objects/organisms in groups based on similar characteristics

Question 25

What is taxonomy?

Answer 25

the study of classifying organisms

Question 26

What are the benefits of classification?

Answer 26

• to simplify the study of organisms

- to allow scientists to communicate with each other