Section 7: Reproduction and Inheritance

Question 1

Where in the cell is the genetic material?

Answer 1

the nucleus

Question 2

what are chromosomes?

Answer 2

long lengths of DNA coiled up

Question 3

what is a gene?

Answer 3

a short section of DNA

Question 4

what does it mean if a cell is diploid?

Answer 4

they have two copies of each chromosome, arranged in pairs

Question 5

what is the diploid number for a human?

Answer 5

46

Question 6

what are alleles?

Answer 6

different versions of the same gene which give different versions of a characteristic, eg blue or brown eyes

Question 7

what are the four different bases which hold together the two DNA strands?

Answer 7

adenine, cytosine, guanine, thymine

Question 8

how are the bases paired?

Answer 8

A-T

C-G

Question 9

what acid is DNA a type of?

Answer 9

nucleic acid

Question 10

what kind of cells does mitosis produce?

Answer 10

genetically identical cells

Question 11

is mitosis involved in asexual or sexual reproduction?

Answer 11

asexual

Question 12

is meiosis involved in asexual or sexual reproduction?

Answer 12

sexual

Question 13

does cloning involve mitosis or meiosis?

Answer 13

mitosis

Question 14

which type of cell division is response for the growth and repair of cells?

Answer 14

mitosis

Question 15

when does meiosis occur?

Answer 15

to produce genetically different cells

Question 16

what is the name for fertilised egg?

Answer 16

a zygote

Question 17

describe tthe structure of DNA

Answer 17

double helix structure. Two strands of DNA are linked by paired bases called adenine, cytosine, guanine and thymine. These bases are paired A-T and C-G. This is called complimentary base pairing

Question 18

what is the relationship between the genes and the characteristics of an organism?

Answer 18

each gene codes for a specific protein, which determines the characteristics an organisms has

Question 19

what does asexual reproduction mean?

Answer 19

a cell replicates itself- only one parent is needed. The offspring will have identical genes to the parent: no variation

Question 20

when a diploid cell divides by mitosis, what do you end up with?

Answer 20

two diploid cells

Question 21

in humans, WHERE is the only place that meiosis occurs?

Answer 21

the reproductive organs: testes and ovaries

Question 22

the gametes contain only 23 chromosomes each. what is the name given to this kind of cell?

Answer 22

haploid

Question 23

when the gametes reproduce by meiosis, what kind of gametes do you end up with?

Answer 23

4 haploid gametes, all genetically different

Question 24

what is the name of the male reproductive part of a flower? what 2 parts does it consist of?

Answer 24

stamen consists of the anther and the filament

Question 25

what does the anther contain?

Answer 25

pollen grains- these produce the male gametes

Question 26

what is the filament?

Answer 26

the stalk that supports the anther

Question 27

what is the name of the female reproductive part of a flower? what 3 parts does it consist of?

Answer 27

the carpel consists of the ovary, style and stigma

Question 28

what is the role of the stigma?

Answer 28

the pollen grains attach to it

Question 29

what does the style do?

Answer 29

it supports the stigma

Question 30

what do the ovaries contain?

Answer 30

the female gametes - eggs

Question 31

what is pollination?

Answer 31

the transfer of pollen from an anther to a stigma, so that the male gametes can fertilise the gametes n sexual reproduction

Question 32

what is cross-pollination?

Answer 32

a type of reproduction in plants where pollen is transferred from the anther of one plant to the stigma of another

Question 33

how do insect pollinated plants' petals differ from wind pollinated ones and why?

Answer 33

insect pollinated: big colourful petals to attract insects as opposed to the small dull ones of wind pollinated plsntd

Question 34

how do the pollen grains of an insect pollinated plant differ from those of a wind pollinated plant and why?

Answer 34

insect pollinated: big, sticky pollen grans to stick to insects as they go from plant to plant wind pollinated: lots of them, small and light to be carried by the wind

Question 35

what is the stigma of a wind pollinated plant like & why? how does this differ from insect pollinated plants?

Answer 35

large and feathery to catch pollen as its carried past by the wind- it also hangs out of the flower. However the insect pollinated plant has a sticky stigma too so that pollen grains picked p by insects stick to it

Question 36

what is the process of fertilisation in plants?

Answer 36

pollen grain lands on stigma pollen tube grows from pollen grain and down the style to the ovary a nucleus from the male gamete moves down the tube to join with a female gamete in the ovary fertilisation is when the two nuclei fuse to make a zygote. this divides by mitosis to form an embryo each fertilised female gamete forms a seed. The ovary develops into a fruit around the seed

Question 37

how do strawberry plants reproduce?

Answer 37

they send out runners- fast growing stems that gro out sideways along the ground the runners take root at various points and new plants start to grow the new plants are clones of the parent strawberry plant, so there's no genetic variation between them

Question 38

where are the sperm made?

Answer 38

the testes

Question 39

sperm mix with a liquid to make what?

Answer 39

semen

Question 40

what is the role of the urethra in the male reproductive system?

Answer 40

carries sperm through the penis during ejaculation (urine leaves the body through here too)

Question 41

what happens to the erectile tissue when the penis becomes erect?

Answer 41

it swells as it is filled with blood

Question 42

what is the role of the glands in the male reproductive system?

Answer 42

produce the liquid to mix with sperm to make semen

Question 43

what is the vas deferens (sperm duct)?

Answer 43

muscular tube carrying sperm from testis towards urethra

Question 44

what does the scrotal sac (scrotum) contain?

Answer 44

the testes

Question 45

how often is an ovum produced?

Answer 45

every 28 days

Question 46

what is the role of the fallopian tube?

Answer 46

a muscular tube that carries the ovum from the ovary to the uterus

Question 47

what 2 things do the ovaries produce?

Answer 47

ova and sex hormones

Question 48

where does the embryo grow?

Answer 48

in the uterus

Question 49

what is the endometrium? & how is it adapted to hold the embryo

Answer 49

the lining of the uterus- has a good blood supply for implantation of an embryo

Question 50

what secondary sexual characteristics does oestrogen cause? (4)

Answer 50

1. pubic hair 2. hips widen 3. breasts develop 4. ovum release- start of periods

Question 51

what secondary sexxual characteristics does testosterone cause in men? (5)

Answer 51

1. hair o face and body (extra) 2. muscles develop 3. penis and testicles enlarge 4. sperm production 5. deeper voice

Question 52

What is the effect of oestrogen?

Answer 52

Causes the uterus lining to thicken and grow, stimulates the release of an ovum (at day 14 of the menstrual cycle)

Question 53

What is the role of progesterone?

Answer 53

Maintains uterus lining- when the level of progesterone falls, the lining breaks down

Question 54

What happens to the levels of progesterone if a fertilised ovum implants in the uterus?

Answer 54

It stays high

Question 55

What are alleles?

Answer 55

Different versions of the same gene that determine a certain characteristic

Question 56

What does it mean if you are homozygous for a trait?

Answer 56

You have two alleles that are the same for that particular gene, eg CC or cc

Question 57

What does it mean if you are heterozygous for a trait?

Answer 57

You have two different alleles for that particular gene, eg Cc