Unit 16 reproduction

Question 1

what is asexual reproduction

Answer 1

the process resulting in genetically identical offspring

Question 2

advantages of asexual reproduction

Answer 2

only one parent is needed which saves time and energy
reproduction is very quick
if there are desirable features, offspring will inherit them

Question 3

disadvantages of asexual reproduction

Answer 3

vulnerable to environmental changes such as disease

Question 4

what is fertilization

Answer 4

the fusion of the nuclei of two gametes that form a zygote

Question 5

what are the nucleus of the gamete

Answer 5

haploid because they have a single set of unpaired chromosomes

Question 6

what are the nucleus of the zygote

Answer 6

diploid and contains two sets of chromosomes

Question 7

advantages of sexual reproduction

Answer 7

variation making it resistant to environmental change
farmers can produce crops that have the best characteristics. This is known as selective breeding

Question 8

disadvantages of sexual reproduction

Answer 8

must spend time and energy looking for a mate
much slower to reproduce

Question 9

what is pollination

Answer 9

the transfer of pollen from the male part of the flower to the female part

Question 10

what is the features of the male part of the plant

Answer 10

called the stamen, made of the anther and the filament

Question 11

what are the features of the female part of the plant

Answer 11

called the carpel, has a stigma with a style connecting it to the ovary

Question 12

where is pollen produced

Answer 12

in the anthers

Question 13

where do the seeds develop

Answer 13

in the ovary

Question 14

what is the function of the sepal

Answer 14

to protect the growing flower and keep it from drying out

Question 15

what is the function of the petal

Answer 15

to attract insects to carry out pollination

Question 16

what is the function of the anther

Answer 16

produce pollen grains which contains male gametes

Question 17

what is the function of the stigma

Answer 17

to trap pollen from other flowers

Question 18

what is the function of the ovary in plants

Answer 18

contains ovules which develop into seeds after fertilization

Question 19

what are features of pollen that is transferred by insects

Answer 19

have a spiky outer layer

Question 20

what are features of pollen that is transferred by wind

Answer 20

lighter and smoother with more being produced

Question 21

what is self pollination

Answer 21

the transfer of pollen grains from an anther to the stigma of the same flower or a different flower on the same plant

Question 22

what is cross pollination

Answer 22

the transfer of pollen grains from the anther of a flower to the stigma of a flower on a different plant

Question 23

features of wind pollinated flower

Answer 23

petals are small and dull
anthers are loosely attached and dangle outside the flower to reach wind
stigma is loosely attached and outside the flower to catch pollen

Question 24

features of insect pollinated flowers

Answer 24

petals large and brightly colored
anther located inside flower to touch insects
stigma located inside flower to touch insects

Question 25

what happens in plants after pollination

Answer 25

a pollen tube begins to grow towards the ovary and sperm moves through the tube

Question 26

what do seeds need to germinate

Answer 26

water oxygen suitable temperature

Question 27

what is the function of the testes

Answer 27

produce sperm cells and testosterone

Question 28

what is the function of the scrotum

Answer 28

contains the testes to keep them at lower temperatures

Question 29

what is the function of the prostate gland

Answer 29

secretes fluid that nourishes and protects the sperm mixture of this liquid known as semen alkaline in nature

Question 30

what is the function of the sperm duct

Answer 30

tube that connects the urethra to the testes

Question 31

what is the function of the urethra

Answer 31

allows semen and urine through the centre of the penis

Question 32

what is the function of the penis

Answer 32

inserted into vagina so that sperm can be transferred into the womans body

Question 33

what is the function of the ovary

Answer 33

produce egg cells and the hormones estrogen and progesterone

Question 34

what is the function of the oviduct

Answer 34

tube connecting an ovary to the uterus

Question 35

what is the function of the uterus

Answer 35

organ in which embryo develops

Question 36

what is the function of the cervix

Answer 36

ring of muscle between vagina and uterus

Question 37

what is the function of the vagina

Answer 37

elastic muscular canal where penis is inserted

Question 38

adaptations of sperm cells

Answer 38

tip of the head(acrosome) secretes digestive enzymes that dissolve the surface of the egg cell flagellum that moves like a tail for movement contains lots of mitochrondria to release energy

Question 39

what do egg cells contain

Answer 39

nucleus surrounded by cytoplasm containing energy stores jelly coating that changes after fertilisation

Question 40

difference between egg cells and sperm cells

Answer 40

egg cells are much longer than sperm cells 40 million- 300 million sperm cells produced per ejaculation but only one egg per month egg cells cannot move on their own but sperm can

Question 41

what happens in early development of they zygote

Answer 41

forms an embryo which is a ball of cells

Question 42

what is the amniotic sac

Answer 42

protective layer that surrounds the fetus

Question 43

what is amniotic fluid

Answer 43

contains nutrients and protects the fetus

Question 44

what is the placenta and its functions

Answer 44

grows and attaches to the wall of the fetus transfers substances from the mother to the fetus transfers waste substances from the fetus to the mother provides a barrier to many toxins and pathogens

Question 44

what isthe main male sex hormone

Answer 44

testosterone

Question 45

what is the main female sex hormone

Answer 45

estrogen

Question 46

what is ovulation

Answer 46

when an egg is released every 4 weeks

Question 47

what is phase one of the menstrual cycle

Answer 47

MENSTRUATION(day 1-5) unfertilized egg,lining of the uterus and blood exit through the vagina

Question 48

what is phase 2 of the menstrual cycle

Answer 48

REPAIR PHASE(day 6-12) blood flow stops lining of uterus thickens and becomes stable changes are triggered by FSH which causes rise in estrogen levels

Question 49

What happens on day 14 of the menstrual cycle

Answer 49

egg is released into the oviduct level of estrogen peaks and stimulates Luteinising hormone which causes ovulation since estrogen is high FSH goes down formation of a corpeus luteum

Question 50

what is day 22-28 of the menstrual cycle

Answer 50

PRE-MENSTRUATION PHASE uterus lining degenerates

Question 51

what hormones are produced by the pituitary gland

Answer 51

Follicle Stimulating Hormones Luteinising Hormone

Question 52

what happens when progesterone levels go higher

Answer 52

FSH and LH go down

Question 53

what is the interaction of the hormones

Answer 53

in beginning FSH is released which causes release of estrogen as estrogen rises FSH is limited LH is stimulated which causes egg to be released progesterone is then produced which inhibits FSH and LH.

Question 54

what does progesterone do

Answer 54

maintains the lining of the uterus

Question 55

what are Sexually Transmitted Infections

Answer 55

infections that are transmitted through sexual contact

Question 56

what is human immunodeficiency virus

Answer 56

HIV is a pathogen that causes an STI which can lead to AIDs

Question 57

how can STIs be stopped

Answer 57

avoid sexual contact contraception

Question 58

what does AIDs do

Answer 58

acquired immune deficiency virus which destroys the bodys immune system