Plant Development
BACK TO BIOLOGY
A. Fruits and Seeds
1. Types
of Fruits (ripened ovaries of flowers)
a. simple dry - single ovary. (nuts, soybean)
b. simple fleshy - single ovary. (cherries, tomatoes,
apples)
c. aggregate - several ovaries in one flower. (strawberries,
raspberries)
d. multiple fruit - ovaries from different flowers join.
(pineapple)
2. Seeds
- ripened ovules
a. seed coat - tough, protective layer that develops
from the wall of the ovule.
b. embryo - develops from the fertilized egg.
- epicotyl - gives rise to the top part of the stem and leaves
- hypocotyl - gives rise to the lower part of the stem
- radicle - gives rise to the root
c. endosperm - food storage tissue.
d. cotyledons - seed leaves
3. Two
classes of angiosperms:
a. monocots - one cotyledon, parallel veins in leaf,
vascular tissue scattered in stem, flower petals in 3s.
b. dicots - two cotyledons, branched veins in leaf, vascular
tissue in rings, flower petals in 4s or 5s.
- endosperm nutrients are absorbed into the cotyledons (2 halves of a peanut)
4. Germination
- the sprouting of a seed.
a. water
b. oxygen
c. warm temperature
d. some need light