Seed Plants Lab

Gymnosperm seeds

“naked”, do not have an ovary that becomes fruit

Angiosperm seeds

covered seeds, do have a covering that becomes a fruit.

Advantages of seeds and pollen

remove need for water in reproduction, outer covering allows it to persist in harsher conditions, stored food helps growth following germination, 

Homosporous

male and female spores appear to be the same

Heterosporous

male and female spores are different

Microspores

produced in microsporangia of pollen cones, turn into male gametophyte (pollen)

Megaspores

developed in the megasporangium, become the female gametophyte, remains in megasporangium of the seed cone. 

Pollen

microgametophyte, produces sperm

Seed parts

Seed coat, food source, embryo

Seed coat

(2n) tissue from the old sporophyte that increases survivability

Food source

(n) tissue from the megagametophyte used by the embryo, (in angiosperms it’s called the endosperm)

Embryo

(2n) grows into the new sporophyte

Primary Growth

Vertical growth

Secondary Growth

Lateral Growth

Ovule

megasporangium (2n) + megaspore (n) + outer layer (2n)

Ovary

vessel or covering that contains the ovule, becomes a fruit

Flowers

For pollination and seed dispersal

Fruit

Seed dispersal

Carpel

female, stigma, style and ovary