BIOL 198 KSU Module 6: Plant Biology

How are Lichens formed?

Lichens form from a mutual relation of Algae and Fungus

What is a lichen good for?

Early colonizers of bore rock, organisms eat them, they provide cover for small organisms, and weavers can use them for dye

Where is Red Algae common?

Red algae is more common in water. Has been found 260m deep

Where is Green Algae common?

Green algae is more common on land, and shares plant characteristics

Why are algae important to humans?

Food, additives, medicine

What biochemical and structural evidence supports that plants and green algae are thought to have common ancestors?

They share cellulose, and have rich cell walls, and there is molecular support as well

What does the life cycle of Chara have that is similar to plants?

It has a haploid and diploid stage, and follows a life cycle

What are the main challenges that needed to be overcome in order for plants to live on land?

Desiccation

Gravity

Mating

Air doesn't filter harmful UV rays

What features of the terrestrial environment made it advantageous for plants to invade land?

Sunlight is abundant, less filter for chlorophyll

CO2 is more readily available

No predators early on

What are the adaptations plants have developed to live today?

Defenses

Live close to water, to combat dryness

Colonized communities with high humidity

All algae are __________

Eukaryotes

What are the 4 major types of plants?

Bryophytes, Seedless Vascular Plants, Gymnosperms, and Angiosperms

In the main dispersal phase, bryophytes' spores are in what state? Haploid or Diploid

Haploid spore

What is the dominant stage (the one we see) of Bryophytes?

Gametophyte, haploid

Since bryophytes have swimming sperm, what is a requirement for reproduction?

They must be in water

Bryophytes can't grow really tall because...

They lack lignin

The sporophyte generation in Bryophytes is ______________ on the gametophyte

Dependent

When a generation is dependent on another, what does this mean?

One produces the other

In the main dispersal stage of seedless vascular plants, is the spore haploid or diploid?

Haploid

What is the dominant stage in seedless vascular plants?

Sporophyte, Diploid

Since seedless vascular plants have swimming sperm, what is a requirement for reproduction?

They must be in water

Why can seedless vascular plants grow tall, unlike bryophytes?

They have Lignin

In Gymnosperms, is the main dispersal stage haploid or diploid?

Diploid

What is the dominant stage in Gymnosperms?

Sporophyte, Diploid

What type of spore does the sperm come from and what type of spore does the egg come from in Gymnosperms?

Microspore = sperm

Megasporte = egg

Gymnosperms have different gametophytes. What does that mean?

Gametophytes cannot live without a sporophyte

In the main dispersal stage of Angiosperms, are they haploid or diploid?

Diploid

What is the dominant stage sporophyte or gametophyte in Angiosperms?

Sporophyte, Diploid

What type of spore does the sperm come from and what type of spore does the egg come from? (Angiosperms)

Microspore = sperm

Megaspore = egg

Do angiosperms have swimming sperm, and require water for fertilization?

No

What role does fruit serve

Protects seeds

What do gametophytes produce? Through what process

Gametes, mitosis

When a male and female gamete meet to form a zygote, this is called....

fertilization

Are sporophytes haploid or diploid?

Diploid

What reproductive cells do sporophytes produce? Haploid or Diploid, and through what division process?

Haploid spores through meiosis

Are gametophytes haploid or diploid?

Haploid

Define vegetative reproduction:

Reproduction that is done asexually resulting in genetically identical offspring

What is a meristem?

The regions of the plant where continuous cell division and growth occurs

Apical meristems are...

located at the tips of stems and roots which cause length growth

Lateral meristems...

facilitate growth in thickness or girth in a maturing plant

Dermal tissue

covers and protects the plant

Vascular tissue

transports water

Ground tissue

serves as a site for photosynthesis

Anther in a flower

holds pollen, the male reproductive cell

Ovary

Female reproductive part of a flower

Ovule

Reproductive cell found in the ovary

Is pollen a sporophyte or gametophyte?

Gametophyte

Vascular bundle

A structure formed by xylem and phloem in the stem

Pith

the ground tissue towards the interior of the vascular tissue in a stem or root

Primary vs Secondary Growth

Primary = length

Secondary = girth

What mode of pollination are modified grasses most likely to use?

Wind

Which agent of pollination is a showy flower, like a petunia going to use

Insects; they like colors

Tap Root System

Has a main root that grows down vertically and from which many smaller lateral roots arise. Penetrates deep into the soil

Fibrous root system

A root system that is located closer to the soil surface, and dorms a dense network of roots that also helps prevent soil erosion

Pollination

The transfer of pollen to the stigma of a flower

Fertilization

The union of the haploid gametes to produce a diploid zygote

What is a seed?

The mature ovule plus stored food

What is a fruit?

A mature plant ovary, containing seed

What is seed germination?

The beginning of growth by a dormant seed

Monocots:

Has flower parts in multiples of 3, fibrous roots, random stem vascular bundles, and parallel leaf vains

Eudicots:

Has flower parts in multiples of 4 or 5, tap roots, circular stem vascular bundles, and net-shaped leaf veins

Define tropism:

The response of a plant toward or away from a stimulus

What is phototropism?

A directional response that allows plants to grow towards (positive), or even away from light (negative).

What is gravitropism?

A growth response to gravity negative is up, positive is down.

Role of cohesion:

Water molecules sticking together allows the water column within the xylem to move as a unit. Works because when water is evaporated, it pulls on the water column

Role of adhesion:

Water molecules sticking to something else- helps prevent water from sliding back down the xylem

Root cap

Protects the tip of the root - gets replaced rapidly

Zone of cell division

zone by the root tip. Made of actively dividing cells

What is the xylem?

The tissue that water and nutrients move through

What is the phloem?

The tissue where glucose and sugars move through

Endodermis

Layer of cells that separated the vascular tissue from the ground tissue in the outer portion of the root

Root hairs

Extensions of the roots, meant to add surface area to the root system.

Route of movement of water from soil to leaves:

Through the endodermis, to the xylem, and out through stomata

Upper epidermis:

Upper tough outer layer of the leaf that helps protect, and support

Leaf vein:

Contains the leaf's xylem, and phloem

Stomata:

Openings in the leaf through which the exchange of gases takes place

Palisade mesophyll

Densely packed photosynthetic cells in the upper part of the leaf

Spongy mesophyll

The loosely packed photosyntheic cells in the upper part of the leaf

Plant adaptations for differing water levels:

Waxy cuticles, leaf hairs, and alternate carbon fixation paths

C3 pathway:

Cost: Photorespiration

Benefit: carbon fixation without using ATP

Habitat: cool and moist

No separation of light-dependent reactions and carbon fixation

C4 Pathway:

Cost: costs ATP to fix carbon twice

Benefits: reduced photorespiration and carbon fixation in high temperatures

Habitat: hot

Spatial separation of light-dependent reactions and carbon fixation

CAM Pathway:

Cost: reduced amount of fixed carbon

Benefits: reduced photorespiration and water loss

Habitat: hot and dry

Temporal separation of light-dependent reactions and carbon fixation

Limiting factors on food production

Amount of land available, amount of arable land, which trophic level providing for, adequate rain and nutrients

Biological factors that limit the conversion of solar energy into food

Wavelengths of light, energy needed to grow/reproduce,

Greenhouse effect

Greenhouse gasses such as CO2 and methane trap heat that would have otherwise radiated back

Mycorrhiza

A type of fungus that form symbiotic interactions with plant roots by secreting enzymes that make minerals water-soluble and absorb those minerals from the soil to transport them to the host plant. The host plant provides food.

Symbiotic nitrogen fixation

A mutually beneficial relationship between a plant (which provides food) and a nitrogen fixing organism

What is the function of the casparian strip?

to force water absorbed through the roots into endodermal cells