Week 4 lecture: Seeds, nuts, fruits, dispersal. Flashcards
Common ground between gymnosperm seeds and angiosperm seeds.
Both have embryo
Both have a food source
both have seed coat.
What is the seed coat made of?
integuments of ovule- parental tissue
What is the nutritive tissue in gymnosperms?
G: gametophyte body grows to become the nutritive source after the sperm come in to the ovule
How does a cone get fertilized?
ovul cone–> sticky liquid traps pollen on female cone –> fertilization –> embryo growth
Downfall of gymnosperm nutritive tissue.
Provisioning before fertilization can be wasteful.
It’s slow-growing (takes several years)
The food supply is the gametophyte tissue remember.
What is the nutritive tissue in angiosperms and how does it develop?
Endosperm:
Via double fertilization (embryo formaiton and nutritive tissue formation)
What are the advantages of double-fertilization in angiosperms?
Development is way faster this way.
Gives female (seed parent) DOUBLE the say over provisioning of nutrition– she can allocate different amounts of food to different seeds whereas the dad just wants to give everythign the same amount.
Monocot v dicot seed
dicot: cotyledon + embryo
monocot: cotyledon + endosperm (most of our food sources) + embryo
What bits of the plant make up most of our diet?
fruits and seeds. (includes nuts, fruits, and all our cereals, rice, pasta groups)
Vegetables don’t make the cut too much except for sotrage roots.
Dry vs. fleshy example
dandelion seeds vs. plum
dehiscent vs. indehiscent
fruit opens vs. doesn’t open
indehiscents are often opened by animals (like squirrels)
Product of 1 ovary vs. 2+ ovaries
1 ovary= peach
2 ovaries or more= tomato
“carp” refers to
things around the seed in the fruit
carpels were all the reproductive bits.
exocarp
skin of a fruit
msocarp
flesh of a fruit
