B8. Reproduction

Question 1

define asexual reproduction

Answer 1

process resulting in the production of genetically
identical offspring from one parent.
process → identical offspring

Question 2

define sexual reproduction (full)

Answer 2

process involving the fusion of haploid nuclei to
form a diploid zygote and the production of
genetically dissimilar offspring.

Question 3

define sexual reproduction (simplified)

Answer 3

fusion of haploid nuclei to form diploid zygote and genetically dissimilar offspring

Question 4

what is a zygote

Answer 4

fertilized egg

Question 5

fertilised egg aka…

Answer 5

zygote

Question 6

what is a gamete

Answer 6

sex cell

Question 7

what happens at fertilisation

Answer 7

during sexual reproduction the gametes fuse

Question 8

pros/ cons of sexual reproduction

Answer 8

pros
-produce genetically different offspring

cons

• requires two parents
• take time and energy
• produce fewer offspring
• good characteristic can be lost

Question 9

pros/ cons of asexual reproduction

Answer 9

• fast: no need to find mate

- good characteristic can be kept

Question 10

define pollination

Answer 10

the transfer of pollen grains from the male part of the plant to the female part of the plant

anther or stamen → stigma

Question 11

define pollination

Answer 11

the transfer of pollen grains from the male part of the plant to the female part of the plant

anther or stamen → stigma

Question 12

describe structure of insect-pollinated flower (full

Answer 12

petal - bright/ scented

nectaries - make nectar(sugary)

stamens:
short filaments
inside flower

carpels:
sticky
inside flower

*for insect to rub against

Question 13

describe structure of wind-pollinated flower

Answer 13

anther -
loosely attached
outside flower

pollen -
large qualities of smooth, light

carpels -
large, feathery stigma
to catch pollen grains

Question 14

describe structure of wind-pollinated flower

Answer 14

anther -
loosely attached
outside flower

pollen - large qualities of smooth, light pollen grains

carpels - large, feathery stigma

*can easily be carried by wind

Question 15

stamen of wind-pollinated flower

Answer 15

long filaments so anthers hang outside flower, loosely attached to filaments, so is blown away easily

Question 16

short filaments, anthers attached to filaments, inside flower for insect to rub against

Answer 16

stamen of insect-pollinated flower

Question 17

structure of insect- pollinated flower

Answer 17

stamens:
short filaments
inside flower

carpels:
sticky
inside flower

*for insect to rub against

Question 18

define germination +*requirement

Answer 18

seeds develops into plants controlled by enzymes

• water - lets seed swell + embryo start to grow
• oxygen - needed for aerobic respiration
• warmth - increases growth rate/ enzyme activities

Question 19

describe dispersal activities

Answer 19

wind - light, has extension

explosive - pods burst open when ripe projecting seeds away

animal internal - brightly coloured, fruit, indigestible coat

animal external - hook

water - waterproof, hollow,float

Question 20

Male reproductive system

Answer 20

1.testes :
inside scrotum
male gametes
testerones

2. scrotum
   aka ball sac
   in/out to control temp
3. sperm duct
   connects testies to urethra

4.prostate gland
secretes fluid for swimming
seminal vesicle: sugar

5.urethra
controls so that urine/semen never pass the same time
prevents loss of urine in sex

6.penis
erect in sex

Question 21

Female reproductive system

Answer 21

Ovaries:
contains follicles
produces/stores egg
oestrogen

Oviducts:
carries ovum to uterus
Fallopian tubes = site of fertilisation

Uterus – where fetus develops

Cervix- ring of muscle, separate vagina from uterus

Vagina: receives sperm from erect penis during intercourse

Question 22

Comparing male and female gametes

Answer 22

size : small x larger

                          movement  tail lashes side to side    x     cilia/peristalsis in oviduct

                        energy store very little - sugar for respiration   protein/fat in cytoplasm - enough to last till implantation

                        number produced  milions constantly x 1/month (puberty → menopause)

chromosomes 23(haploid number)

Question 23

Describe fertilisation

Answer 23

joining of nuclei of male gamete (sperm) and female gamete (egg)

Question 24

the function of the placenta

Answer 24

Blood from the fetus passes through the umbilical cord in the umbilical artery to the placenta.
Here it comes close to the mother’s blood.
transport O2 + nutrients (amino acids, glucose…) from mother —> fetus
transport CO2 + wastes (urea… ) from fetus —>mother (through umbilical vein).

• transfers O2 from mother to fetus
  
  • transfers nutrients (of named nutrients) from mother to fetus
  • transfers CO2 from fetus to mother
  • transfers wastes (or named wastes) from fetus to mother
  • allows the transfer of antibodies from mother to fetus
  • prevents mixing of the blood of mother and fetus.

Question 25

the function of the Umbilical cord

Answer 25

joins fetus to placenta; contains:
2 arteries: blood from fetus —> placenta
1 vein: returns blood —> fetus

Question 26

Indicate the functions of the amniotic sac

and amniotic fluid.

Answer 26

Amniotic sac: membrane from embryo cells: encloses fetus, prevents entry of bacteria

Amniotic fluid: supports, protects fetus from mechanical damage; absorbs urine released by fetus.

Question 27

Describe the function of the placenta and umbilical cord

Answer 27

Umbilical cord

• joins fetus to placenta
• artery: fetus —> placenta, waste
• vein: placenta —> fetus, oxygen n food

2. Placenta

Brings blood supply of fetus close to mother’s
-site of gas exchange, nutrients, waste