16: 1.2.3

Question 1

what is assexual reproduction?

Answer 1

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

Question 2

advantages and disadvantages of assexual reproduction

Answer 2

advantages- only one parent is needed, saving energy
-quicker reproduction
-easier reproduction

disadvantages- as all parents and offsprings are the same, they become more vulnerable to environmental changes

Question 3

examples of things that reproduce assexually.

Answer 3

starfish, bacteria, many plants

Question 4

what is sexual reproduction

Answer 4

process involving the fusion of the nuclei of two gametes to form a zygote and the production of offspring that are genetically different from each other

Question 5

what is fertilisation

Answer 5

the fusion of the nuclei of gametes

Question 6

advantages and disadvantages of sexual reproduction

Answer 6

advantages- introduces variation in population
-in wild variation makes it more resistent to environmental changes and to disease
-farmers can chose best characteristics from two different stains to produce new varities of plants, selective breeding

disadvantages- time and energy needed
-much slower than assexual

Question 7

function and description of sepal

Answer 7

green part at the top of the stem, underneath the petals
to protect the growing flower and help to stop it drying out

Question 8

function and description of petal

Answer 8

brightly coloured part of the flower
to attract insects, birds or mammals to carry out pollination

Question 9

function and description of stamen

Answer 9

the male part of the flower consisting of the filament and the anther
to produce male gametes (pollen) and provide the correct structures and conditions necessary for the transfer of pollen

Question 10

function and description of filament

Answer 10

the stalk that supports the anther
to hold the anther in a position where it is able to transfer its pollen to an insect, mammal or bird

Question 11

function and description of anther

Answer 11

coloured, usually with a powdery appearance
to produce pollen grains, which contain the plant’s male gametes

Question 12

function and description of stigma

Answer 12

usually green and the tallest part of the inside of the flower, and with a sticky, waxy layer
to trap pollen from other flowers

Question 13

function and description of style

Answer 13

the thin structure that supports the stigma and is above the ovary
to support and present the stigma in a position where it can receive pollen from an insect, bird or mammal

Question 14

function and description of carpel

Answer 14

the female part of the flower that contains the stigma, style and ovary
to produce female gametes and provide the correct structures and conditions necessary for fertilisation

Question 15

function and description of ovary

Answer 15

green, bulb-shaped part near the bottom of the flower
contains ovules (which contain the female gametes) which will develop into seeds after fertilisation

Question 16

function and description of ovule

Answer 16

structures within the ovary
female gametes are produced and contained within the ovules. Upon fertilisation, these ovules will develop into seeds

Question 17

function and description of petal (wind pollination)

Answer 17

small and usually dull in colour because they do not need to attract insects

Question 18

function and description of anther (wind pollination)

Answer 18

loosely attached and dangle outside the flower so its pollen can be blown easily by the wind

Question 19

function and description of stigma (wind pollination)

Answer 19

loosely attached and dangle outside the flower so they can catch wind-borne pollen from other plants; often appear feathery

Question 20

what is pollination?

Answer 20

transfer of pollen grains from the anther to the stigma.

Question 21

description for pollen transported by insects

Answer 21

has a spiky outer layer, which hooks onto insects so that the pollen can be transported from one flower to another

Question 22

description for pollen transported by wind

Answer 22

smaller, lighter, and smoother allows flower grain to be blown from one flower to another

Question 23

what is self pollination?

Answer 23

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

Question 24

what is cross pollination?

Answer 24

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

Question 25

advantage and disadvantage of self pollination

Answer 25

do not need to rely on pollinators, can grow in areas which pollinators dont live

reduces variation, and ability for plants to respond to changes in enviorment eg disease and change in climate

Question 26

advantage and disadvantage of cross pollination

Answer 26

variation increases within a population of plants
relies on pollinators to transport pollen

Question 27

when does fertilisation occur

Answer 27

when a pollen nucleus fuses with a nucleus in an ovule

Question 28

describe the growth of the pollen tube and fertilisation

Answer 28

after pollination, pollen tube grows through the style towards the ovary, male gametes move through this tube eventually this tube reaches ovule. Nucleus of one of the sperm cells fuses with egg cell nucleus (fertilisation), forming a zygote, develops into an embryo which then develops into a plant.

Question 29

what is germination

Answer 29

seeds will be dispersed away from the parent plant. In the right conditions, they will begin to open

Question 30

what is needed for germination (conditions)

Answer 30

right temperature, warmth
right amount of water
and oxygen