BSC 2011C Exam 3 Review Matthew Tye UCF

Strategies of early plants adapting to land

Live near water, tolerance to desiccation, stay small in size, mechanisms against UV radiation

Adaptations to terrestrial life

1. Alternation of Generations life cycle

2. Apical meristem in roots and shoots

3. Waxy cuticle

4. lignin in vascular tissues

5. Sporopollenin

waxy cuticle

prevents water loss

Apical meristems

Specialized zones of growth found at the tips of plants

Lignin

substance in vascular plants that makes cell walls rigid

sporopollenin

a layer of durable polymer that prevents exposed zygotes from drying out

First terrestrial plant strategies

LIVE NEAR WATER

develop mechanism to protect from UV Rays

develop tolerance to desiccation

humid enviros

stay small

What is the dominant stage of the seedless plant life cycle

Sporophyte stage

Bryophytes

A moss, liverwort, or hornwort; a nonvascular plant that inhabits the land but lacks many of the terrestrial adaptations of vascular plants.

What type of plant is a bryophyte

A non vascular seedless plant

What plant is the closest living relative to earliest terrestrial plants

Bryophytes

Characteristics of bryophytes

No vascular tissues, limited in size, gametophyte stage dominant, homosporous, thallus and rhizoids

gametangia

Sex organ that produces gametes in plants

Where does the gametangia grow from in bryophytes

The thallus

What are the 3 types of bryophytes

mosses, liverworts, hornworts

Thallus

The body of a plant-like organism that is not divided into leaves, roots, or stems.

Rhizoids

A thin, rootlike structure that anchors non vascular plants to the ground and absorbs water and nutrients.

Is non vascular seedless plant fertilization water dependent

Yes because male gametes swim

How does fertilization of non vascular seedless plants occur

Sperm is released from antheridia and swim to the archegonia

Antheridia

Structures in plants that produce male gametes

Archegonia

Structures in plants that produce female gametes

What is the dominant stage of a vascular seedless plant

Sporophyte

Is the fertilization of seedless plants water dependent

Yes

What is the conductive vascular tissue of seedless plants

Xylem, phloem

Xylem

vascular tissue that carries water upward from the roots to every part of a plant (water conducting tissue)

Phloem

Complex tissue which acts as a transport system for soluble organic compounds within vascular plants ( food conducting tissue)

Do non vascular seedless plants have roots, stems or leaves

No

Do vascular seedless plants contain roots stems and leaves

Yes

Why did vascular seedless plants adapt to have leaves

Greater photosynthetic efficiency

Types of leaves

microphylls and megaphylls

microphylls

spine shaped leaf with single strand of vascular tissue, only in lycophytes

megaphylls

larger leaves with a highly branched vascular system

sporophylls

modified leaves that bear sporangia

Where can sporophylls be found

In both microphylls and megaphylls

sori

clusters of sporangia

strobili

cone-like structures formed from groups of sporophylls

sporangia

multicellular organs that produce spores

Are seed plants sporophyte of gametophyte dominant

Sporophyte dominant

What happens to the gametophyte of a seed plants

Gametophyte become microscopic structure inside the sporophyte

ploidy level of sporophyte

diploid (2n)

Ploidy level of gametophyte

haploid (n)

What do sporophytes (zygote) produce?

haploid spores by meiosis

Antheridium produces what?

sperm

Archegonium produces what?

eggs

Are zygote diploid or haploid

Diploid

How do seed plants reproduce without water

The evolution of pollen meant seeds were no longer dependent on water for reproduction because pollen could travel by wind rather than water

What do gametophytes produce?

gametes by mitosis

Disadvantages of terrestrial plants

threat of desiccation, UV rays, need structural support, plant reproduction is water dependent, zygote is water dependent

Advantages of terrestrial plants

•Sunlight is abundant

•Carbon dioxide is abundant

•No competitors for resources

•No predators

Heterospory

produces both microspores (male gametophytes) & megaspores (female gametophytes)

How does heterospory appear in seed plants

Megaspores which develop into female gametophyte and microspores which develop into male gametophyte

How does fertilization work for seed plants

When pollen lands on female gametophyte a pollen tube will grow towards the egg

Gymnosperms

A plant that produces seeds that are exposed rather than seeds enclosed in fruits

examples of gymnosperms

conifers, cycads, and ginkgophytes

What protects the naked seeds (gymnosperms)

Woody leaves called sporophylls

tracheid

hollow plant cell in xylem tissue with thick cell walls that resist pressure

Monoeicious

male and female flowers on the same plant

Diocous

Plants have male flowers (cones) on one plant and female flowers (cones) on a different plant

How are gymnosperms pollinated?

by wind

Angiosperms

flowering plants that produce seeds in fruit

What is the most dominant species of plant on earth

Angiosperms

Adaptations of angiosperms

flowers and fruits

Why did angiosperms adapt to have fruit

For embryo protection and dispersal

Why did angiosperms adapt to have flowers

Pollination and protection

Are angiosperms monoecious or dioecious

both perfect flowers are monoecious and imperfect flowers are dioecious

How are angiosperms pollinated

Vio wind insects and mammals

Function of vessel cells in xylem tissue of angiosperms

Efficient at conducting water

Male sex organ of angiosperms

Stamen (androecium)

What do stamen produce

Microspores which develop into pollen

Female sex organ of angiosperms

Carpel (gynoecium)

Function of carpel

Contains megasporangia

What is the end product of double fertilization of angiosperms

A diploid zygote and triploid endosperm

How does reproductive mutualism work with angiosperms and animals

Pollination and dispersion of seeds