4.6 Reproduction Flashcards Preview

11B1 - AQA Biology Trilogy > 4.6 Reproduction > Flashcards

Flashcards in 4.6 Reproduction Deck (72)
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1

A cell divides in a series of stages called

the cell cycle

2

What are the initial steps in the cell cycle?

The cell grows and organelle numbers increase, DNA replicates.

3

In the cell cycle after the DNA has replicated what happens next?

The copied chromosomes separate (mitosis) and then the cell divides into two.

4

What are the 2 forms of reproduction?

Asexual and sexual

5

Why is asexual reproduction important?

growth and repair

6

How many parents are involved in asexual reproduction?

1

7

How many parents are involved in sexual reproduction?

2

8

Which form of reproduction involves gametes?

sexual - fusion of egg and sperm

9

Which form of reproduction brings about variation?

sexual

10

Name an organism that reproduces asexually

bacteria, daffodil bulbs, strawberry tubers

11

Name an organism what reproduces sexually

humans

12

What form of cell division produces gametes?

Meiosis

13

Where does meiosis occur?

testes and ovaries

14

Where does mitosis occur?

in all body cells except testes and ovaries

15

In plants what are the sex cells?

pollen and egg cell

16

In animals what are the sex cells?

egg cell and sperm

17

What is another name for a gamete?

sex cell

18

Why does sexual reproduction bring about variation

Involves FUSION of egg and sperm, creating a unique combination of alleles

19

How many chromosome pairs are found in human body cells?

23 pairs

20

How many chromosomes are found in human sex cells

23

21

Chromosomes are found

in the nucleus

22

Chromosomes are made up from

DNA

23

Put the following in order of size starting with the smallest

cell, gene, nucleus, chromosome

gene, chromosome, nucleus, cell

24

What are genes?

Short sections on DNA found on chromosomes - they code for a particular characteristic

25

How are mitosis and meiosis different?

Mitosis is used for growth and repair, meiosis makes gametes

26

How many times does the cell divide in meiosis?

twice

27

How are the cells produced different from the parent cell in meiosis

they have half the chromosome number

28

How many cells are produced at the end of meiosis?

4

29

How many cells are produced at the end of mitosis?

2

30

At fertilisation what happens to the chromosome number?

It doubles and chromosome number is restored.