2.7 (P2) Genetic Variation Flashcards Preview

AQA GCSE - Biology > 2.7 (P2) Genetic Variation > Flashcards

Flashcards in 2.7 (P2) Genetic Variation Deck (27)
Loading flashcards...
1

What does sexual reproduction lead to?

Variation

2

How many chromosomes are in a human body cell?

46

3

How many pairs are in a human body cell?

23

4

How many chromosomes in a gamete?

23

5

What are the female chromosomes?

XX

6

What are the male chromosomes?

XY

7

What are some characteristics controlled by?

1 gene = 2 alleles

8

What is an allele?

A version of a gene

9

What can the allele do?

Control the development of a characteristic

10

What is a dominant allele?

Always expressed in the phenotype even if another allele if present

11

What is a recessive allele?

Only expressed in the phenotype in the absence of a dominant allele

12

What is the equation used to describe characteristics?

Genotype + environment -> phenotype

13

What is your genotype?

Genes an organism possess

14

What is your phenotype?

Observable characteristics

15

What is heterozygous?

An organism containing cells with 2 different alleles for 1 gene

16

What is homozygous?

An organism containing cells with 2 of the same alleles

17

What is this...?
Aa

Heterozygous

18

What is this...?
AA

Homozygous dominent

19

What is this...?
aa

Homozygous recessive

20

What is polydactyly caused by?

A dominant allele

21

What is Polydactyly?

Having extra fingers or toes

22

What is cystic fibrosis caused by?

A recessive allele

23

What is cystic fibrosis?

A disorder of cell membranes causing thick, sticky mucus

24

What is the process of checking unborn babies for genetic diseases?

Embryonic screening

25

What molecules are chromosomes made up of?

DNA

26

What phrase describes DNA?

Double helix

27

What does a gene code for?

A particular combination of amino acids with make a specific protein