Gymnosperms - Lecture 8

Gymnosperms & Angiosperms both had evolution of ________ _____, allowing for wood and cork growth laterally.

Secondary growth

Secondary growth occurs in the ________ _________, occuring in a ring shape in Eudicots

Vascular cambium

The vascular cambium divides producing _______ to the inside and _______ outside

Xylem, Phloem

The ______ is responsible for WOOD

Xylem

The _______ ___________ divides producing cork cells or bark.

Cork cambium

__________ are seeded vascular plants

Spermatophytes

Evolution of the seed occurred in both __________ and ________

Gymnosperms, Angiosperms

Early seed evolution resulted from a ________ droplet, liquid secreted by young ovule. Earliest pollination mechanisms

Pollination

Steps in seed evolution

1. Heterospory (2 sexes and sizes of haploid spores)

2. Endospory (development of female gametophyte)

3. Reduction to 1 megaspore (other 4 aborted)

4. Retention of megaspore (within microsporangium)

5. Evolution of the integument and micropyle (envelopment of megasporangium)

____ sporangium produce female spores

MEGA

_____spore produce male spores

MICRO

_________ is where plant had 1 spore size with 1 sex

Homospory

Gymnosperms have ___ integument, attached (INCOMPLETE)

1

Angiosperms have ___ integuments, attached within a modified leaf (carpel)

2

Gneteles contain _ families.

3

Gneteles are a unusual group because…

Considered to be close to angiosperms by some, but not related to others.

Contain traits from Gymnosperm lineage

3 families in Gneteles

1. Ephadraceae (Mormon Tea Family)

2. Welwitshiaceae (Desert plant)

3. Gnetaceae (Tropical vines)

Ginkgoaceae are the last ________ member of the order Ginkgoales

Living

________ is what most people think of when they say gymnosperms

Conifers

Families in Conifera

1. Pinaceae (Pines, 4 native to TX)

2. Cupressaceae (Cypress)

3. Podocarpaceae (yellow-wood)

Pine family has needle like leaves joined together in ______ (shown in bottom right of image)

Fascicles

Is this a male or female pine cone?

Female

Is this a male or female pine cone?

Male

How can we tell how old a tree is?

Counting the rings