Meiosis

Question 1

Chromosomes contain the genetic information which is passed from

Answer 1

generation to generation as genes

Question 2

Each gene is a short length of a

Answer 2

chromosome

Question 3

A gene is a

Answer 3

short length of a chromosome

Question 4

A gene has an effect on the cell by

Answer 4

having the information to cause a protein to be made

Question 5

What effect does the gene have on a cell

Answer 5

It provides the cell with information to make a protein

Question 6

How many chromosomes do humans have?

Answer 6

46

Question 7

Chromosomes can be ordered in pairs by

Answer 7

size and shape

Question 8

ordered pairs of chromosomes are called

Answer 8

homologous pairs

Question 9

Homologous pairs of chromosomes are called this because

Answer 9

they both have genes for the same characteristic

Question 10

Pair 23 does what?

Answer 10

Determines the sex of the person

Question 11

Pair 23 is called the

Answer 11

Sex chromosomes

Question 12

If a person has two X chromosomes they are

Answer 12

female

Question 13

If a person has an X and a Y chromosome they are a

Answer 13

male

Question 14

The other 22 chromosome pairs that aren’t sex chromosomes are called

Answer 14

autosomes

Question 15

Mitosis: Before a cell division every chromosome

Answer 15

replicates to give two chromosomes which are identical

Question 16

Mitosis: Replication before mitosis ensures that

Answer 16

both daughter cells get a copy of every gene

Question 17

Mitosis: Replication begins by unzipping the DNA molecule by

Answer 17

breaking the hydrogen bonds between the bases

Question 18

This process of breaking the hydrogen bonds requires

Answer 18

Enzymes and Energy from ATP

Question 19

Mitosis: Free DNA nucleotides join to the

Answer 19

exposed bases on both strands

Question 20

Mitosis: The new nucleotides join with each other by

Answer 20

phosphate to deoxyribose sugar

Question 21

Mitosis: This process produces two chromosomes that are

Answer 21

identical to each other

Question 22

Meiosis is a type of cell division in which a gamete mother cell with 46 chromosomes produces

Answer 22

four cells with 23 chromosomes

Question 23

Cells with only 23 chromosomes are called

Answer 23

haploid cells

Question 24

When a haploid sperm fertilizes a haploid ova resulting in a

Answer 24

diploid zygote

Question 25

Before meiosis each chromosome replicates to give

Answer 25

two identical chromatids joined by centromere

Question 26

At the start of the first meiotic division the nuclear membrane

Answer 26

disappears to allow easy chromosome movement

Question 27

At the same time the chromatids

Answer 27

shorten by coiling to prevent tangling

Question 28

The spindle arranges the chromosomes along the

Answer 28

equator in homologous pairs

Question 29

The homologous pairs may cross over points this is called

Answer 29

chiasmata

Question 30

The spindle pulls one member of each homologous pair to

Answer 30

each pole at random

Question 31

The random way in which 23 pairs of chromosomes are pulled to the poles is known as

Answer 31

independent assortment

Question 32

Independent assortment leads to

Answer 32

great variation in the gametes produced

Question 33

The cytoplasm is divided by a membrane giving two cells with

Answer 33

23 chromosomes, each made up of two chromatids

Question 34

In the second meiotic division the chromosomes in both cells are lined up singly along the

Answer 34

equator by the spindle fibers

Question 35

The chromatids are separated by the spindle fibres and

Answer 35

pulled to the poles of the cells

Question 36

Cytoplasmic division by membranes gives

Answer 36

4 cells

Question 37

Variation in gametes results from

Answer 37

the independent assortment of homologous chromosome pairs in the 1st division

Question 38

Extra variation in gametes results from

Answer 38

chromosomes breaking at chiasmata and rejoining with a different chromosome

Question 39

What processes ensure that every gamete used in conception is genetically unique?

Answer 39

Independent assortment and crossing over