Gymnosperms

Question 1

Transition from pteridophytes to gymnosperms? What was the big picture?

Answer 1

Big picture was the evolution of the seed
PTERIDOPHYTE
-establish extreme heterospory
-reduction in number of megasporocytes and megaspores
*-retention of megaspore IN megasporangium
-megagametophyte develops into megasporangium
-Developement of integument=seed coat
-developement of microphyte= opening
GYMNOSPERMS

Question 2

What are the four major phyla of gymnosperms?

Answer 2

Gnetophyta
Cycadophyta
Ginkgophyta
Coniferophyta

Question 3

Gnetophyta

Answer 3

-immature seed with fleshy seed coat
-not a fruit
-exposed ovules develop seeds

Question 4

Cycadophyta

Answer 4

-Sporophylls
- Exposed ovules on megasporophylls
-Male and female “cones” (strobili)

Question 5

Ginkgophyta

Answer 5

-Only one species: Ginkgo biloba (maidenhair tree)
* Highly resistant to pollution – common
urban landscape tree
* Exposed ovules
* Fleshy seed coat
* Are NOT fruits
* Smell really bad
when ripe

Question 6

What do ginkgophyta leaves shaped like?

Answer 6

fan shaped

Question 7

Sporophyte parent tissue cycle (also look at picture in notebook)

Answer 7

Megasporophyte —> goes through meiosis —-> megaspore —-> megasporopyte —-> EGG