Meiosis And Variation

Question 1

Homologous chromosomes

Answer 1

The two chromosomes in a pair.

Same centromere position, same length, genes for same characteristics

Question 2

Genes that are found on the same chromosome are called

Answer 2

Linked genes

Question 3

How are homologous pairs made

Answer 3

One copy of the chromosome has come from the female parent and the other copy from male parent

Question 4

Each gamete is

Answer 4

Haploid And has a single set of Chromosomes

Question 5

A cell with full double set of homologous chromosomes is

Answer 5

Diploid

Question 6

Meiosis produces

Answer 6

Genetically variable haploid cells which develop into gametes

Question 7

Mitosis produces

Answer 7

Genetically identical diploid cells to make a multicellular organism

Question 8

Meiosis

During Interphase, the homologous chromosomes duplicate so each is now made up of two _____

Answer 8

sister chromatids

Question 9

At the start of meiosis 1 ___

Answer 9

Homologous chromosomes pair up so that they are aligned gene by gene

Question 10

The homologous pairs when they are aligned link to form a

Answer 10

Bivalent

Question 11

Genetic makeup is unique due to two processes during meiosis-

Answer 11

Crossing over

Independent assortment

Question 12

Crossing over

Answer 12

During meiosis 1 homologous pairs of chromosomes swap part of genetic material

Question 13

Independent assortment

Answer 13

Chromosomes from each pair are randomly allotted to the daughter cells irrespective of their maternal and paternal origin

Question 14

Chiasma

Answer 14

Formed at crossing over position between homologous pairs

Question 15

How many chiasma do human chromosomes usually have

Answer 15

Two or three

Question 16

What do chiasmata do

Answer 16

Allow exchange of sections of dna between homologous chromosomes

Question 17

Cytokinesis

Answer 17

Separates two cells

Question 18

Mieosis 1 summary

Answer 18

• crossing over
• number of chromosomes halved, going diploid to haploid
• one cell splits to produce two genetically different cells
• each chromosome present in both cells has Teo sister chromatids which are no longer identical

Question 19

Linked genes

Answer 19

Found on the same chromosome and therefore passed on together

Question 20

Meiosis 2

Answer 20

Each of the two cells produces in meiosis 1 undergoes a further division during which the sister chromatids of each chromosome are separates

Question 21

In mammals what gene controls the development of male caharcteristics

Answer 21

SRY sex determining region of Y chromosome

Question 22

Heterogametic

Answer 22

Makes- XY

Question 23

Homogametic

Answer 23

Females XX

Question 24

Use linkage map to

Answer 24

find distance between linked genes and their frequency of recombination

Question 25

Gamete mother cell

Answer 25

Gametocyte

Question 26

X chromosome inactivation

Answer 26

Most of the X chromosome is permanently switched off

Question 27

What advantage does x chromosome inactivation have

Answer 27

In female cells prevents a double dose of gene products which could be harmful to cells

Question 28

How to find the number of different combinations of chromosomes

Answer 28

2 to power of haploid number