Topic 3 - Genetics Flashcards Preview

GCSE Combined Biology (Edexcel) > Topic 3 - Genetics > Flashcards

Flashcards in Topic 3 - Genetics Deck (48)
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1

Which structures are found inside the nucleus?

chromsomes

2

Which substance forms a long strand in each chromosome?

DNA

3

How do body cells make copies of themselves?

cell division, mitosis

4

How many chromosomes are there in a human body cell nucleus?

46

5

What happens in fertilisation?

two gametes fuse

6

What is the name of the cell formed in fertilisation?

zygote, fertilised egg cell

7

Which term means producing more of the same kind of organism?

reproduction

8

What is the name of the human male gamete?

sperm cell

9

The DNA strand in a chromosome contains sections that carry instructions for characteristics. What are these sections called?

genes

10

What molecule forms the genome of an organism?

DNA

11

Where are genes found?

[in sections of DNA] on chromosomes

12

What does a gene carry the instructions for?

making a protein

13

A protein is made by linking together smaller molecules. What are these smaller molecules called?

amino acids

14

What is any molecule made of repeating units called?

a polymer

15

A human cell contains 46 strands of DNA. Is it diploid or haploid?

diploid

16

Are the cells produced by meiosis haploid or diploid?

haploid

17

Are the cells produced by mitosis haploid or diploid?

diploid

18

What shape is DNA?

a double helix

19

What is a chromosome made out of?

DNA and proteins [to package the DNA]

20

What shape is a DNA molecule?

double helix

21

What part of a DNA strand contains the instructions for a protein?

gene

22

What are the letters of the bases that form the DNA code?

A,C,T and G

23

How do these bases pair up in DNA?

A with T, C with G

24

Apart from bases, what other parts are needed in a DNA molecule?

phosphate group, sugar

25

What is one phosphate group, one sugar and one base called?

nucleotide

26

Why is DNA a polymer?

It is made of many nucleotides joined in a chain.

27

Give an example of a protein.

any example. E.g. an enzyme

28

How is the active site of an enzyme formed?

by folding of protein/polypeptide/amino acid chains

29

Why are proteins polymers?

They are made of many amino acids joined in a chain.

30

How many bases does a codon contain?

three