pollination

Question 1

describe how pollen grains are produced

Answer 1

a young anther had 4 spaces inside it called pollen sacs before the flower bud opens

some cells around the edges of the pollen sacs divide to make pollen grains

when flower bud opens, anthers split and open and pollen grains fly out

Question 2

what do pollen grains look like?

Answer 2

fine, often yellow powder

under microscope - some are spiky and some smooth

each grain surrounded by hard coat for harsh conditions

coat protects male gametes inside grains as they are carried from one flower to another

Question 3

describe female gametes in plants

Answer 3

inside ovules in the ovary

each ovule has a nucleus

fertilisation occurs when an ovule nucleus fuses with a pollen grain nucleus (like in humans!)

Question 4

define pollination

Answer 4

the transfer of pollen grains from the male part of the plant (staMEN) to the female part of the plant (stigma)

Question 5

define self-pollination

Answer 5

the transfer of pollen grains to the stigma of the same flower (or different flower but same plant)

so pollen grain doesn’t have to travel far

Question 6

define cross-pollination

Answer 6

transfer of pollen to the stigma of a different plant of the same species

Question 7

what do the petals do?

Answer 7

they are colourful structures that attract pollinators

Question 8

what is the stamen?

Answer 8

the entire male part of the flower

Question 9

what is the anther?

Answer 9

the male part of the flower where pollen grains are made

Question 10

what does the filament do?

Answer 10

holds up the anther

Question 11

what is the carpel?

Answer 11

the entire female part of the flower

Question 12

what does the stigma do?

Answer 12

it is sticky and receives the pollen

Question 13

what does the style do?

Answer 13

holds up the stigma

Question 14

what does the ovary do?

Answer 14

holds the ovules

Question 15

what is the ovule?

Answer 15

it is located inside the ovary and contains the female gametes

Question 16

describe the process of insect pollination

Answer 16

insects attracted by flower colour and scent

bee follows guidelines to nectaries brushing past anthers so pollen sticks to its body

when bee goes to another flower it transfers some pollen onto its stigma

Question 17

describe the process of wind pollination

Answer 17

wind pollinated flowers produce more pollen usually since most goes into the air

wind blows pollen from anthers to stigma of flowers

Question 18

describe adaptations of insect pollinated flowers

Answer 18

• large petals with guidelines often
• strongly scented
• nectaries at base of petals
• anthers inside flower so insect has to brush past them to reach nectar
• stigma inside flower so insect has to brush past to reach nectar
• sticky/spiky pollen grains, sticks to insects
• quite large quantities of pollen, some will be eaten/delivered to wrong type of flower

Question 19

describe the adaptations of wind pollinated flowers

Answer 19

• small petals or none at all
• no scent
• no nectaries
• anthers dangle outside flower where they can catch wind
• stigmas large and feathery and dangle outside flower, pollen can land on it
• smooth, light pollen, can be blown in wind
• very large quantities of pollen, most will blow away/get be lost