Lecture 8 DA Flashcards
What is the lifecycle of an angiosperm like?
It is fast, flower in days and pollinate to produce fruit within weeks.
What is a stamen, and what does it contain?
Is the male part, contains pollen.
What is a stigma, and what does it contain?
Is the female part, leads to the ovary via the pollen tube.
What is the pollen tube?
Pollen enters here, leads to the ovary.
What is found in an angiosperm’s ovary?
Unfertilised ovule.
What is the androecium and gynoecium? Are they diploid?
Androecium - pollen
Gynoecium - Egg
Both haploid.
How is pollen formed?
Starts off as diploid, undergoes meiosis, forming 4 pollen grains or microspores.
Are sporophytes haploid or diploid?
Diploid.
How is an angiosperm egg formed?
Starts as a megaspore, which is diploid, and undergoes meiosis. Produces 4 haploid cells, 3 degenerate (polar bodies), leaving only 1 viable cell. This undergoes mitosis 3 times to have 8 total.
Where are the egg cells of angiosperms found?
Within the embryonic sac. Two polar bodies found in the middle, alongside the other 8 eggs.
Are pollen specific?
Yes, so specific pollinators needed to be viable. Length of the stigma used for specificity.
What happen after pollination?
Pollen tube discharges 2 sperms, one fertilises the egg, another fuses with a polar body.
What is the endosperm? Why is it important?
A triploid bosy formed when a sperm fuses with a polar body after pollination. Allows the seed to tap into nutrients before photosynthetic capability with its cotyledon. Major evolutionary advantage.
What does the seed become?
Seed to fruit.
What does the ovule become?
Ovule to seed.
What does the integument become?
Integument to seed coat/testa.
What does the ovary wall become?
Ovary wall to fruit wall/pericarp/
What does the floral tube become?
Floral tube and perianth - may persist to form fruit wall.
What is a fruit?
Mature ovary-bearing seed.
What are the twomain ways of categorising fruit?
- How it originates - multiple, aggregate or simple.
- Tissue type - fleshy/dry, single/multi-seeded, dehiscent/indehiscent.
What are the three types of carpels, and what do they form?
- Monocarpous - single, most legumes
- Syncarpous - many fused, most flowers
- Apocarpous - many distinct fused
How does a simple fruit form?
2 ways:
- Single carpel, from one ovary of monocarpous flower.
- United carpel, from one ovary of syncarpous flower.
How does an aggregate fruit form?
From a cluster of simple fruits, from apocarpous flower.
Formed from a group of ovaries as a single receptacle.
How does a multiple fruit form?
Develops from many individual flowers.
Fuse together to form a single mass.
What are 3 types of multiple fruits, and where are they derived from?
Strobilis - dry, cone-like fruit.
Synconus - fleshy fruit derived from the capitulum.
Sorosis - fleshy fruit derived from spikes.
What is a drupe? Where does its different layers develop from?
Single seeded fleshy fruit. Hard endocarp, which is a seed. Mesocarp is flesh andd exocarp is skin.
Collectively the pericarp.
What are the four types of simple, multiseeded fleshy fruits?
- Pome
- Berry
- Pepo
- Hesperidium
What does a pome develop from?
Fruit forms from ovary wall and floral tube.
What does a hesperidium develop from?
Ovary wall with leathery rind, skin has oils.
What does a berry develop from?
Fleshy ovary wall.
What does a pepo develop from?
Ovary wall is hard.
What are the two kinds of dry fruit? How do they release seeds?
Dehiscent - opens to release seeds.
Indehiscent - doesnt open to release seeds.
What dehiscent fruits are composed of 1 carpel?
Follicle Legume Capsule Porose Circumscissile Loculicidal Valvate Septicidal
How does a follicle and legume fruit open?
Follicle - splits along one suture
Legume - splits along 2 sutures
How does a capsule and porose fruit open?
Capsule - dehisce through pores, slits or valves
Porose - from pores
How does a circumscissile and loculicidal fruit open?
Circumscissile - transverse split through centre, opens like a lid
Loculicidal - split along carpels or locules
How do valvate and septicidal fruit open?
Valvate - tip of capsule splits
Septicidal - splits along edge of carpels or locules
What dehiscent fruits are composed of more than one carpel? What are they like?
Siliqua - long slender pod
Silicula - short broad pod
What are the three indehiscent fruit types?
Samara
Achene
Nut
What is a samara like?
Pericarp is winglike.
What is an achene like?
Fruit is small with a thin wall.
What is a nut like?
Fruit is large with a thick stony wall.
What are schizocarps? List the three types.
Carpels split at maturity, forming 1 seed unit called mericarp.
Lomentum
Cremocarp
Carcerulus
What is a lomentum like?
Fruit splits transversely
What is a cremocarp like?
Fruit from an inferior ovary, splits vertically into 2 mericarps.
What is a carcerulus like?
Fruit from a superior ovary, splits vertically into 2 mericarps.
What is a caryopsis? Give an example.
Seeds unite to pericarp all around - grains.
What are seeds? Are they diploid or haploid?
Mature ovules, are diploid.
That is the testa?
Seed coat.
Where is the food reserve found? What do dicots and monocots use?
Known as the cotyledon, used mostly by dicots, larger seeds.
Monocots use endosperms.
From seed to plant, what do the following turn into?
Cotyledon
Plumule
Radicle
Cotyledon - leaf
Plumule - shoot
Radicle - root
How do plants undergo asexual reproduction?
Done by budding, or offshoots.
Are identical to the parent.
Name 4 asexual reproduction methods in plants.
- Modified stems
- Parthenogenesis
- Vegetative propagation
- Tissue culture propagation
What are some above ground vegetative propagation types (2)?
Runners
Weed
What are some underground vegetative propagation types (4)?
Rhizomes
Tubers
Corm
Bulbs
What are some forms of natural cloning?
Inbreeding
What are some forms of artificial cloning?
Cuttings, tissue culture, genetic engineering.
What is a disadvantage of cloning?
Lose the ability to flower, or cope with environmental changes.
