Lab 5: gymnosperms

Gymnospores are:

“naked seeds”. vascular plant with seeds that do not develop within an ovary

Dominant generation of gymnosperms

Sporophyte

What are the 4 phyla of gymnosperms?

1) cycads

2) gnetophyta

3) ginkgoes

4) conifers

Derived trait of gymnosperms (and angiosperms)

seeds

Seeds are:

Multicellular structure with embryo, food reserves, and protective coat

Benefits of seeds over spores

• multicellular

• germinate deeper in soil

• more reserves for growth

What are the types of heterospores?

• microspores: male (smaller)

• megaspores: female (bigger)

Microspores form what?

Pollen (male gametophytes)

What are found inside the female ovule?

megaspore that produces archegonia (female gametophyte)

What carries sperm to the egg?

pollen tube (no swimming)

Adaptations of gymnosperms

• vessels

• vascular cambium (or lateral meristem)

• cone arrangment/structure of gymnosperms

What does the vascular cambium do?

produces wood to allow for bigger/taller growth

Differentiate monoecious and dioecious

• monoecious: one house (one plant has male/female reproductive structures)

• dioecious: two houses (male/female reproductive structures on different plants)

What kind of reproductive structure system do cycads have?

Dioecious

Cycads produce:

cones (gymnosperm)

Identify the organism and the structures indicated

Cycad
a) male cone

b) female cone (with seeds)

What kind of reproductive structure system do ginkgoes have?

dioecious

Leaf structure of ginkgoes

deciduous and dichotomously veined leaves

Why are ginkgoes called the “living fossil”?

Thought to be extinct / only one living species: ginkgo biloba

Identify the species that this leaf comes from 

ginkgo

Identify the organism and the structures indicated

Ginkgo biloba

a) female cones

b) male pollen cones

Gnetophyta reproduction:

gymnospermous

Gnetophyte: welwitschia

mostly underground, but 2 leaves. African deserts, moisture from fog

Gnetophyte: ephedra

photosynthetic stems. Medicinal purposes by Native Americans and settlers

Gnetophyte: Gnetum

Tropical, includes vines and trees

Identify the organism depicted

Ephedra

Identify the organism depicted

Welwischia

Identify the organism depicted

Gnetum

Conifer pines reproductive structures:

• pollen (male) cones small

• seed (female) cones large

Conifer forms of leaves:

1) needle-like

2) scale-like

3) awl-like

Conifer growth kinds:

1) primary growth: growth in height

2) secondary growth: growth in girth (xylem)

Conifer seed breakdown:

embryo (2n) and food (1n gametophyte tissue) inside a seed coat

Identify the leaf form depicted

Needle-like

Identify the leaf form depicted

Scale-like

Identify the leaf form depicted

Awl-like

This cross section is of a(n) _________. Identify the structures

pine needle
a) stoma

b) resin duct

c) xylem

d) phloem

Distinguish the two types of cones depicted:

a) male cone (with pollen)

b) female cone (seeds)

This cross section is of a(n) _________. Identify the structures indicated by the red arrows

male pollen grain

wings (aid in pollen dispersal)

These cross sections are of a ____________ and a _________. Identify the structures indicated by the red arrows

female pine cone, ovule

a) ovule

b) archegonium

c) female gametophyte

d) integument