L19 - Gymnosperms

Why don't gymnosperms have fruits?

They lack ovaries

Types of cones

Seed (female) and Pollen (male)

Nutritive Tissue

the remains of the megagametophyte

Subgroups of Gymnosperms

Cycads

Ginkgo

Gnetophytes

Conifers

Cycads

have large, compound leaves

dioecious

dioecious

separate male and female plants

monoecious

having both the male and female reproductive organs in the same individual

How are cycads pollinated?

insects

How are other gymnosperms pollinated?

wind

Ginkgo

two lobes (biloba)

dioecious

motile sperm

produces seeds with fleshy covering (NOT FRUIT)

Gnetophytes

includes welwitschia, ephedra, gnetum

What characteristics of Gnetophytes are similar but are not homologous to angiosperms?

vessel elements and double fertilization

Welwitschia

live in fog deserts

leaves are indeterminate

Conifers

trees

produce cones of varying sizes

needle-like leaves

monoecious

(T/F) The taiga is dominated by conifers

True

Taiga

Biome in which the winters are cold but summers are mild enough to allow the ground to thaw

Serotiny

an adaptation in plants where seeds are only released when there is an environmental trigger

Endemism

ecological state of a species being unique to a defined geographic location

Coast Redwood

tallest trees in the world

Growth Rings

secondary growth varies by the season and results in rings

How do growth rings look during the spring?

larger diameter, relatively thinner cells, lighter in color

How do growth rings look during the summer?

smaller diameter, thicker cells, darker in color