Meiosis Flashcards Preview

Life Sciences > Meiosis > Flashcards

Flashcards in Meiosis Deck (104)
Loading flashcards...
1

What is the control centre for all cellular activities?

The nucleus

2

What happens just before cell division?

The chromatin network contracts and becomes visible as individual chromosomes

3

What does each chromosome consist of?

DNA molecules wrapped around proteins

4

What makes up genes?

DNA molecules

5

Do all organisms have the same number of chromosomes?

No

6

How many chromosomes do humans have?

46

7

What happens during DNA replication?

single-stranded chromosomes replicate to become double stranded

8

What does a double-stranded chromosome consist of?

two chromatids joined by a centromere

9

What joins chromatids?

a centromere

10

What does replication ensure?

that all daughter cells contain the same hereditary information as the parent cells

11

When are chromosomes arrached in pairs called homologous chromosomes?

just before cell division

12

What is similar between each chromosome of the homologous pair?

They are the same length and contain the same genes

13

How many chromatids does one pair of homologous chromosomes contain?

4

14

What are autosomes?

The are chromosomes that control features in males and females

15

What are gonosomes?

They are sex chromosomes that determine the sex of the organism.

16

How many types of gonosomes are there?

2 (X & Y)

17

What are some features that could be controlled by autosomes?

eye colour
blood group

18

What is meiosis?

A special type of cell division necessary for sexual reproduction

19

What type of cell does the process of meiosis begin with?

one diploid (2n) cell

20

What does diploid imply?

That it is a cell containing two copies of each chromosome
One copy from the organism's father; one copy from the organism's mother

21

Define karyotype

The number and appearance of chromosomes in the nucleus of a cell

22

What does the process of meiosis produce?

four haploid cells
These are all genetically different from each other

23

Define fertilisation

When one of the haploid male gametes fuses with one of the haploid female gametes

24

What does fertilisation produce?

a diploid zygote

25

What describes the complete set of chromosomes in a species or in an individual organism?

Karyotype

26

Where does meiosis occur?

In the gonads

27

What are the gonads?

Reproductive organs (testes and ovaries)

28

What are the cells produced by meiosis called?

gametes

29

What can the process of meiosis also be called?

gametogenesis

30

What are the male gametes called?

spermatozoa (sperm cells)