Plant Reproduction - Structure + pollination

Question 1

Structure of insect pollinated flower (non-reproductive organ)

Answer 1

Receptacle - stem that connects flower to plant
Sepal - set of leafs cover + protect flower when still developing (dull colour, strong)
Petal - brightly coloured leaf to attract insect for pollination

Nectary - produce nectar with scent to attract pollinators

Question 2

Structure of insect pollinated flower (reproductive organ)

Answer 2

Stamen
-Anther: produce spore with male gamete via mitosis + meiosis - burst to release pollen
-filament: stalk provide structural support to anther, deliver food + water via vascular bundle

Carpel
-stigma: sticky surface allowing pollen to stick on
-style: allow access for male gametes to ovule
-ovary: membrane containing ovule
-ovule: contain egg cell for fertilisation

Question 3

Why is insect pollinated flower effective

Answer 3

Bright colour leaf to attract insect
Nectar underneath flower - insect craw lower to get more pollen on them
When pressure applied to petal - push anther + stigma up to pollination
Another + stigma enclosed

Question 4

Structure of wind pollinated flower

Answer 4

No petal + dull colour lead
No nectar + scent

Stigma + anther hang outside to catch wind
Stigma feathery = more SA
Anther loosely attached = shake more easily

Question 5

Why wind pollinated flower effective

Answer 5

Hang outside of plant =
Release + recieve pollen from wind better

Nothing blocking pollen

Question 6

Diagram of insect pollinated flower

Answer 6

https://resource.download.wjec.co.uk/vtc/2020-21/el20-21_1-2/4.2-plant-reproduction-image-1-en.jpg

Question 7

Diagram of wind pollinated flower

Answer 7

https://resource.download.wjec.co.uk/vtc/2020-21/el20-21_1-2/4.2-plant-reproduction-image-2-en.jpg

Question 8

Difference in pollen

Answer 8

Insect:
Produce small amount of pollen
Sticky
Large + heavy

Wind
Produce large amount of pollen - more chance of fertilisation
Has air sacs to float in air
Small + light

Question 9

Cross pollination

Answer 9

Reproduction between different plants of same species

Adv:
-genetics variation: lots of flowers to mate- adaption more likely for external factor
-less reliant on self reproduction system

Disadv:
-Dilute genetic stability if already adapted well
-rely on external factors or pollinator

Question 10

Self pollination

Answer 10

Self reproduction - own pollen to stigma

Adv:
-maintain genetic stability
-don’t rely on external factor to carry pollen

Disadv:
Less genetic diversity
If any reproductive organ damaged = can’t reproduce

Question 11

Plant adaptation to promote cross pollination

Answer 11

Chemical incompatibility- chemical generated by own stigma do not activate own pollen

Development of sex organ - develop anther first then die off and develop stigma or vice versa

Separate gender - one plant cant produce both male + female gametes

Question 12

Structure of anther

Answer 12

Vascular bundle - phloem nutrient, xylem water
Tapetum - membrane encapsulating pollen
-providing nutrient + water proof prevent pollen drying out
Pollen sac - sac containing pollen + membrane
Epidermis - layer surprising anther

Question 13

Anther diagram picture

Answer 13

https://media.sciencephoto.com/f0/41/97/55/f0419755-800px-wm.jpg