reproduction Flashcards

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1
Q

what are the advantages of asexual reproduction?

A
  • useful when the environment is stable
  • completed much faster
  • enables an organism to quickly populate
  • more time + energy efficient
  • if it’s well adapted to its environment, successful characteristics are carried on
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2
Q

what are the disadvantages of asexual reproduction?

A
  • disease likely to affect the whole population as there is no genetic variation
  • population is only suited to one habitat
  • population is vulnerable to changes in conditions
  • limited genetic variation in population
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3
Q

what are the two types of cell division?

A

mitosis and meiosis

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4
Q

what is the use of meiosis?

A

to produce gametes for sexual reproduction

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5
Q

what is the use of mitosis?

A

growth and repair

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6
Q

how many daughter cells are made in mitosis?

A

two genetically identical daughter cells

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7
Q

are offsprings from sexual reproduction genetically identical?

A

no, they are genetically different

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8
Q

how many chromosomes do the daughter cells contain and why is this important?

A
  • 23 (a haploid amount)
  • important so zygote has correct number when gametes fuse
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9
Q

how many daughter cells are produced in meiosis?

A

4 genetically different daughter cells

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10
Q

how many cell divisions occur in mitosis and meiosis?

A
  • 2 cell division in meiosis
  • 1 cell division in mitosis
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11
Q

how does sexual reproduction lead to variation in offspring?

A

there are two parent cells, so two sets of genetic information

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12
Q

where does mitosis occur?

A

all body cells, except the gametes

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13
Q

where does meiosis occur?

A

only in the gametes

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14
Q

what is the function of the sepal?

A

to protect the unopened flower

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15
Q

what is the function of the petal?

A

may be brightly coloured to attract insects

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16
Q

what is the function of the stamen?

A

male part of the flower, comprising an anther attached to the filament

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17
Q

what is the function of the anther?

A

produces the male sex cells (pollen)

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18
Q

what is the function of the stigma?

A

the top of the female part go the flower, which collects pollen grains

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19
Q

what is the function of the ovary (plants)?

A

produces the female sex cells (contained in the ovules)

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20
Q

pollination definition.

A

pollination is the transfer from anther to stigma of a plant

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21
Q

position of stamen in insect pollinated plants

A

enclosed so the insect has to make contact

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22
Q

position of stamen in wind pollinated plants

A

exposed so pollen can easily blow away

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23
Q

position of stigma in insect pollinated plants

A

enclosed so insect has to make contact

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24
Q

position of stigma in wind pollinated plants

A

exposed to catch pollen blowing in the wind

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25
Q

type of stigma in insect pollinated plants

A

sticky so pollen grains can attach from insects

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26
Q

type of stigma in wind pollinated plants

A

feathery so it can catch pollen grains blown by

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27
Q

size of petals in insect pollinated plants

A

large and colourful to attract insects

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28
Q

size of petals in wind pollinated plants

A

small because it doesn’t need to attract insects

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29
Q

colour of petals in insect pollinated plants

A

bright and colourful to attract insects

30
Q

colour of petals in wind pollinated plants

A

dull, green mostly

31
Q

nectary’s in insect pollinated plants

A

present - they produce nectar, a sweet liquid containing sugars as a reward for insects

32
Q

nectary’s in wind pollinated plants

A

not present - don’t need to attract insects

33
Q

pollen grains in insect pollinated plants

A

sticky and large

34
Q

pollen grains in wind pollinated plants

A

smaller, smooth, inflated grains to carry in the wind

35
Q

what is self-pollination?

A

when pollen goes from the anther to the stigma of the same plants, this can result in a genetically weaker plant

36
Q

what is cross-pollination

A

when pollen goes from one plant to another of the same type, this results in stronger plants

37
Q

fertilisation definition

A

the fusion of gametes to form a zygote

38
Q

the order of pollination and fertilisation in a plant.

A
  1. a pollen grain on the stigma grows a tiny tube, all the way down the style to the ovary. (pollen tube releases digestive enzymes to digest way through tissue of style into ovary)
  2. the pollen tube carries a male gamete to meet a female gamete in an ovule
  3. the pollen tube curves around the ovule to enter the opening in an ovule
  4. the tip of the tube dissolves and allows the pollen grain nucleus to move out of the tube and into the ovule
  5. the nucleus of the pollen grain MUST fuse with the nucleus of the ovum for fertilisation to occur
  6. the two gametes join and their chromosomes combine, so that the fertilised cell contains a normal complement of chromosomes, with some from each parent flower
  7. after fertilisation, female parts of the flower develop into a fruit seed
  8. the rest of the carpel becomes a fruit
39
Q

name 4 methods of seed dispersal

A
  1. wind dispersal
  2. water dispersal
  3. animal dispersal
  4. bursting
40
Q

what does a seed contain?

A
  • a plant embryo
  • root (radical)
  • shoot (plumule)
  • one or two seed leaves
  • starch
41
Q

what 3 factors are required for successful germination?

A
  • water
  • oxygen
  • warmth
42
Q

what are the male gametes called?

A

sperm cells

43
Q

when are male gametes produced?

A

always, continuously from birth

44
Q

where are the male gametes produced?

A

testes

45
Q

function of the bladder

A

the body’s urine storage tank

46
Q

function of the sperm duct

A

sperm passes through and mixes with fluids containing nutrients

47
Q

function of the testes

A

exocrine gland - produces sperm via meiosis
endocrine gland - produces testosterone

48
Q

function of the seminal vesicle

A

produces a fluid which mixes with the sperm to form semen

49
Q

function of the urethra

A

tube inside penis which carries urine/semen - contains ring of muscle which prevents them mixing

50
Q

function of the penis

A

passes urine out of the body and passes semen into the vagina

51
Q

function of the scrotum

A

pouch which holds the testes - must be held outside body as sperm production requires a lower temperature of 35 degrees

52
Q

function of the prostate gland

A

produces seminal fluid

53
Q

what are the female gametes called

A

egg cell

54
Q

where are the female gametes released from?

A

ovary

55
Q

function of the fallopian tube

A

connects the ovary to the uterus, lined with cilia that waft the egg along and into uterus, site of fertilisation

56
Q

function of the uterus

A

a muscular bag with soft lining, where foetus develops until birth

57
Q

function of the cervix

A

a ring of muscle - keeps foetus inside uterus

58
Q

function of ovaries

A

have hundreds of undeveloped ova - one is released per month

59
Q

function of the vagina

A

muscular tube that leads from the cervix to outside the body

60
Q

what is the purpose of the villi in the placenta?

A
  • increases surface area:volume
    -> increases rate of diffusion
    -> nutrients can be transported faster
61
Q

why should the blood flow in opposite directions in the placenta?

A
  • to stop it mixing
    -> possibility of different blood types
    -> the body will try fight the other blood type
  • maintain concentration gradient across whole blood vessel
62
Q

adaptations of the placenta

A
  • large surface area with villi
  • good blood supply -> maintain concentration gradient
  • keeps harmful molecules out
63
Q

where its produced and function of testosterone

A

testes - to produce sperm

64
Q

where its produced and function of FSH

A

pituitary gland - stimulates egg development and ovulation

65
Q

where its produced and function of oestrogen

A

ovaries - stimulates thickening of uterus lining

66
Q

where its produced and function of LH

A

pituitary gland - surges to stimulate ovulation, causes egg to mature

67
Q

where its produced and function of progesterone

A

ovaries - maintains uterus lining, stops production of FSH and LH

68
Q

which hormones increase on day 4 of menstruation

A

FSH and ovulation

69
Q

which hormones increase of day 14 of ovulation

A

LH and progesterone

70
Q

how can plants reproduce asexually

A

BUDDING
- process in which a new plant grows out of the bud on the parent plant

RUNNERS
- grow side shoots called runners via mitosis

71
Q

role of the amniotic fluid in protecting the foetus

A
  • protects the foetus from jolts and bumps
  • keeps temperature fairly constant
72
Q

how is the foetus protected by amniotic fluid

A
  • a membrane called amnion (amniotic sac) encloses the foetus
  • this secretes a fluid called amniotic fluid