Unit 2 : Chapter 11

Question 1

Sexual reproduction

Answer 1

Method of producing offspring in which an egg and sperm fuse to form a zygote

Question 2

Gametes

Answer 2

Eggs or sperm cells

Question 3

Sperm

Answer 3

Male gametes produced in the testes

Question 4

Egg

Answer 4

Female gametes produced in the ovaries

Question 5

Gonads

Answer 5

Organs in which gametes are formed; ovaries or testes

Question 6

Ovaries

Answer 6

Egg producing organ

Question 7

Testes

Answer 7

Male gonad that produces both sperm and male hormones`

Question 8

Hermaphrodites

Answer 8

Has egg producing and sperm-producing organs

Question 9

Chromosomes

Answer 9

Thread-like structure composed of DNA and protein, and visible in cells during mitosis and meiosis

Question 10

Somatic cells

Answer 10

refers to cells of the body other than germline cells

Question 11

Diploid number

Answer 11

refers to organisms or cells having two copies of each specific chromosome, that is, having a paired set of chromosomes

Question 12

Homologous pairs

Answer 12

refers to members of a matching pair of chromosomes

Question 13

How many cells are in a gamete

Answer 13

46

Question 14

Haploid number

Answer 14

Having one copy of each specific chromosome: that is, having a set of unpaired chromosomes

Question 15

Meiosis

Answer 15

Reduction division
Process of cell division that results in the production of new cells, each containing half the number of chromosomes of the original cell

Question 16

Fertilisation

Answer 16

Union of egg and sperm to form a zygote

Question 17

Metaphase 1

Answer 17

Replicated chromosomes form homologous pairs, attached to spindle fibres and lined up in the middle

Question 18

Anaphase 1

Answer 18

Pairs of homologous chromosomes move independently to opposite ends of the cell towards poles
Independent assortment

Question 19

Telophase 1

Answer 19

Cytoplasm begins to divide and the chromosomes are now haploid
The cells are not identical due to crossing over

Question 20

Metaphase 2

Answer 20

Chromosomes in both cells line up on the equator, attached to spindle fibres

Question 21

Anaphase 2

Answer 21

Sister chromatids separate and move to separate poles

Question 22

Telophase 2

Answer 22

Chromosomes are decondensing
The nuclear membrane is reforming
Spindle fibre is breaking down

Question 23

Prophase 1

Answer 23

Homologous pairs line up and non-sister chromatids cross over

Question 24

Prophase 2

Answer 24

Nuclear membrane disintegrates; chromosomes become attached to spindle fibres at centromeres and move toward the centre

Question 25

independent assortment

Answer 25

Non-homologous pairs pulled away at anaphase to create more genetic divirsity

Question 26

Simultaneous hermaphrodism

Answer 26

Is when the species contains both egg and sperm-producing organs

Question 27

Sequential hermaphrodites

Answer 27

When the species can change from having egg-producing organs to sperm-producing organs

Question 28

Reduction division

Answer 28

A cell begins with 46 chromosomes reduces to gametes with 23 chromosomes

Question 29

Reduction division

Answer 29

A cell begins with 46 chromosomes reduces to gametes with 23 chromosomes

Question 30

Meiosis facts

Answer 30

It halves the chromosome number from 46 to 23 Produces random combinations ie; genetic divirsity Crosses over to create new genetic combinations

Question 31

Difference in mitosis and meiosis

Answer 31

Meiosis occurs in germ cells in ovary/testes Meiosis is for the production of gametes, whereas mitosis is for growth and repair Meiosis is 2 divisions, mitosis is one Meiosis has a pair of matching chromosomes, mitosis doesn't Crossing over occurs in meiosis Meiosis produces 4 haploid gametes unidentical and mitosis produces 2 identical daughter cells

Question 32

Nondisjunction

Answer 32

When chromosomes fail to join or separate at anaphase, where there are two copies or a chromosome is missing

Question 33

Advantages of sexual reproduction

Answer 33

Genetic diversity | Better equipped to survive a disease outbreak

Question 34

Disadvantages of sexual reproduction

Answer 34

The energy required for the process and the finding of a suitable partner Cannot reproduce quickly

Question 35

External fertilisation

Answer 35

When animals release their gametes into the external environment to be fertilised outside of the female

Question 36

Internal fertilisation

Answer 36

When males deliver sperm directly into the reproductive system of females so fertilisation occurs inside the body