B5.1

Question 1

What is a gamete

Answer 1

A sex cell - egg/sperm

Question 2

What is an allele

Answer 2

Different versions of the same gene

Question 3

What is a phenotype

Answer 3

Visible characteristics of an organism

Question 4

What are the causes of variation

Answer 4

Genetic material

Environmental factors

Question 5

What is a genotype

Answer 5

Collection of alleles that determine characteristics

Question 6

What is a genome

Answer 6

The entire genetic material of an organism

Question 7

What is discontinuous variation

Answer 7

Characteristics that can be put into categories

Question 8

What is an example of a discontinuous variation

Answer 8

Blood group, eye colour, sex

Question 9

What is continuous variation

Answer 9

Variation that shows a wide range of values - can be measured

Question 10

What are some examples of continuous variation

Answer 10

Height, weight, foot length

Question 11

What do genetic and environmental variation combine to produce

Answer 11

Different phenotypes

Question 12

What’s the cause of continuous variation

Answer 12

Genetic and environmental

Question 13

What’s the cause of discontinuous variation

Answer 13

Genetic

Question 14

What is asexual reproduction

Answer 14

A clone of an organism that is genetically identical to its parent

Question 15

What organisms reproduce asexually

Answer 15

Bacteria - E-coli 
Potato plants 
Spider plants
Daffodils 
Star fish

Question 16

What is sexual reproduction

Answer 16

Involves two parents and the joining of male and female gametes during fertilisation

Question 17

Why do plants produce sexually

Answer 17

To create a new seed

Question 18

Advantages of sexual reproduction

Answer 18

• produces genetic material in the offspring
• species can adapt to new environments, due to variation - survival advantages
• disease is less likely to effect all the individuals in a population

Question 19

What is a disadvantage of sexual reproduction

Answer 19

• requires two parents - slower

Question 20

Advantages of asexual reproduction

Answer 20

• population can increase rapidly when conditions are favourable
• one parent needed
• more time and energy efficient
• faster

Question 21

Disadvantages of a sexual reproduction

Answer 21

• no genetic variation
• species may only be suited to one habitat
• disease would effect all individuals in a population

Question 22

What is fertilisation

Answer 22

When the nuclei of a female and make gamete fuse to create a zygote

Question 23

What type of cell are gametes

Answer 23

Haploid - half the dna needed

Question 24

What are the gametes in flowering plants

Answer 24

Pollen - male

Ovules - female

Question 25

How are gametes made

Answer 25

Using meiosis

Question 26

Describe the process of meiosis

Answer 26

• dna is replicated
• chromosomes pair up and line up on midline
• if chromosomes touch - parts of genetic material cross over - genetic variation
• spindle fibres contract - pull each chromosome to different sides
• cell divides in 2

Stage 2

• chromosomes are not copied
• pairs line up along midline
• spindle fibres contract - pull
• cell divides

Question 27

What does meiosis form

Answer 27

Four separate cells with 23 chromosomes - genetically different

Question 28

What’s the differences between meiosis and mitosis

Answer 28

Mitosis

• divides once
• produces 2 cells
• 46 chromosomes each
• used for new body cells
• happens in all parts of body

Meiosis

• divides twice
• produces 4 cells
• 23 chromosomes each
• used to make gametes
• happens in testes/ ovaries