Plants Study Set 2

What is the CO2-water trade off?

When stomata open and close for gas exchange, water passively diffuses out creating a liability

Evolutionary, what were the first plants that appeared?

Green algae

What plants evolved after algae?

Bryophytes

What plants evolved after bryophytes?

Ferns

What plants evolved after ferns?

Gymnosperms

What plants evolved after the gymnosperms?

Angiosperms

What are algae?

Early aquatic organism, sisters to land plants, resemble the ancestor of land plants, few adaptations to survive

What are lichens?

Fungus that have symbiotic relationships with algae, covering the algae preventing it from drying, receiving nutrients from its photosynthesis

What are the 3 kinds of bryophytes?

Liverworts, mosses, and hornworts

What are the 4 challenges plants must face when going on land?

Retaining moisture, competing for light, dispersing their gametes/offspring, and protecting their offspring

What are liverworts?

Earliest plants on land, type of bryophytes, very small

How have bryophytes evolved to retain moisture?

They grow very low and spread out in moist places to keep their water

How have bryophytes adapted to completing for light?

Specially adapted to take advantage of the low intensity light that filters through forest canopies

What does mitosis result in?

Two daughter cells with the same number of chromosomes as the mother cell

What does meiosis result in?

Four daughter cells with half the number of chromosomes as the mother cell

What is an archegonium?

Female structure of a plant

What is an antheridium?

Male structure of a plant

What is a gametophyte?

Haploid phase of a plant that produces the gametes

What is a sporophyte?

Diploid phase of a plants life cycle that produces spores

What phase of a bryophytes life cycle is dominant?

Gametophyte and Haploid

In bryophytes, what process creates spores?

Meiosis

In bryophytes, what process creates sperm & egg?

Mitosis

What part of a liverworts life cycle is diploid?

Only the embryo & zygote, as soon as it develops into a spore it becomes haploid again

What part of the liverworts life cycle life cycle is haploid?

Everything but the embryo; the spore, the grown plants (archegonium & antheridium), and the gametes

How do bryophytes disperse their gametes?

Sperm swims through the moisture and water around them to find an egg

How do bryophytes disperse their spores?

Spores germinate in the thallus and begins growing right away, dropped near the original plant

How do bryophytes protect their offspring from dryness and heat?

They don’t

What part of mosses is the sporophyte?

The top stalk, the seta and the capsule

What part of mosses is the gametophyte?

The bottom leafy part

What is the key adaptation that ferns have?

Vasculature

What are xylem?

Vasculature in plants that transport water

What are phloem?

Vasculature in plants that transports sugar

How do ferns adapt to retain moisture?

By transporting moisture and nutrients through Vasculature (veins) that run throughout the plant

How do ferns adapt to compete for light?

Their Vasculature allows them to grow further upright towards the sky reaching out with their leaves

What part of the life cycle is dominant for ferns?

The sporophyte (diploid) phase

How do ferns disperse their spores?

They fall from the leaves, travel by wind, not very far

How do fern protect their offspring?

They don’t

What 2 key adaptations developed at gymnosperms?

Wood and seeds

What is homospory?

One kind of spore is produced that can germinate into male/female or bisexual (bryophytes & ferns)

What is heterospory?

Two different types of spores, male and female, that provide outcrossing and greater genetic diversity (gymnosperms & angiosperms)

In gymnosperms what is an ovulate cone?

The female cone that produces megaspores and grows into megagameotphytes

In gymnosperms what is a pollen cone?

The male cones that produce microspores that grow into microgametophytes

What phase of the life cycle is dominant in gymnosperms?

Sporophyte and diploid

What is advantageous about a seed?

Protects the offspring, embryo can remain dormant inside until conditions are right for germination, specialized structures all them to travel further

What does alternation of generations mean?

Like ferns, the gametophyte lives freely from the sporophyte and dies when the sporophyte develops