Biology Lecture Exam 2

Moss Embryo

Immature sporophyte, nurtured by gametophyte at some point

Liverworts

Has 5200 species, small and inconspicuous, Sporophyte is very tiny compared to large gametophyte

Gemma Cups

Small cuplike structures on surface of gametophytes, responsible for asexual reproduction (fragmentation)

How do plants breath

Through stomata

How do liverworts breathe

Breathe through pores that can’t open or close

Antheridia (sperm) and Archegonia (eggs)

Specialized reproductive structures made by gametophyte in bryophytes, Antheridia produces sperm and Archegonia produces eggs

Elaters

Helical shaped cells that aid in spore dispersal and increase in size when damp

How much can moss absorb

Can absorb 20x it’s dry weight

What are the two types of cells in moss

Dead

Living

Dead moss cells (Hyaline cells)

Absorbs and holds water

Living moss cells

Perform photosynthesis

Why is the fossil record for bryophytes poor

Because bryophytes are soft-bodied and lack vascular tissue

Sphagnum moss spore launch

Sporophyte connected to gametophyte, dries out, pressurizes, and explosively pops open the operculum(cap) releasing spores

How fast can the sphagnum launch spores

60 mph

Who did research on plant movement

Joan Edwards

Moss Gametophyte

Helically arranged leaves, conductive tissue consists of hydroids and leptoids

What are the two types of conductive tissue in moss gametophytes

Hydroids and Leptoids

Hydroid

Carry water

Leptoid

Carry sugars

How many guard cells do Moss have

1 used for the pore

Dung Moss (Splachnum Rubrum)

Moss that grows where dung is

Disjunct Distribution

Occurs when the same species is found in two or more widely separated geographic areas.

Who proposed that dung moss species was separated by birds

Lily Lewis

Why did Winona Welch study moss

She felt bad for them

Longest cryogenic suspension for plants

20 years

Longest cryogenic suspension for animals

10 years (Tardigrade)

Can you freeze bryophytes and reanimate it

Yes bryophytes have amazing regeneration capacity, an example being in Antarctica

Oldest regrowth of moss

1500 years (millennial timescale regeneration)

Amount of Moss species

10,000

Amount of Hornwort species

300 (least diverse bryophyte group)

Why is Hornwort Anthoceros a puzzling group

Has Photosynthetic sporophyte

Basal Meristem

Like a vascular plant

Basal Meristem

Growth tissue at the base that makes new cells

Why are hornworts considered free-living

Stomata ( Does not open or close)

Photosynthesis

Basal Meristem

Has pyrenoid that enhances photosynthesis by concentrating co2

Why are spores in tetrads

They are in tetrads because of meiosis

Pseudo-elaters

cells in hornworts that twist as they dry, helping disperse spores, not true elaters because they develop differently

Closest bryophyte to vascular plants

Hornworts

Most seedless vascular plants are

Ferns

Characteristics of Seedless Vascular Plants

Heteromorphic AOG

Dominant Sporophyte

Xylem Phloem

Roots, Leaves and Stems

Tissue Systems ( Dermal, Vascular, Ground)

Primary and Secondary Growth

Three tissue systems of seedless vascular plants

Dermal

Vascular

Ground

How do we use seedless vascular plants everyday

We use it for energy, the 60% of coal we use is mostly seedless vascular plants

How did plants stand so tall back then

Vascular Tissue System (Xylem, Phloem)

Production of Lignin

Xylem

Moves water and minerals from roots to rest of the plant

Phloem

Moves sugars produced by photosynthesis to other parts of the plant

Why are tree fern cross sections different

For more efficient transport, leaf traces, no secondary growth

Primary Growth

Comes from apical meristem, increases tree height and produces primary tissues, what most seedless vascular plants do, produce herbs

What type of growth does seedless vascular plants do

Primary Growth and Secondary Growth

Secondary Growth

Comes from the cambial meristem,

increases stem root and diameter,

produces secondary tissues and secondary xylem (wood)

Create tree rings,

Tracheids

Transport water and minerals, give plant structure and allows it to not be crushed during transport (apart of xylem)

Heterospory

Adds another layer to AOG, sporophyte produces microspores and megaspores

Microspore

Makes a microgametophyte(pollen) that produces sperm

Megaspores

Makes a megagametophyte that will produce eggs

Homospory

Plant produces only one type of spore

Can seedless vascular plants be either heterospory or homospory

Yes

What happens to antheridia and female gametophyte if plant is heterosporous (seedless vascular plants)

Antheridia disappears, Female gametophyte is reduced(can be found in megaspore wall)

Germination

A spore or seed starts growing

Suspensor

Grows in embryo, pushes the developing embryo into nutrient-rich female gametophyte tissue, helping the embryo obtain nutrients during development.

Whisk Ferns (Psilotum)

Tiny Leaves

No Roots

Rhizome and arial stem
Very Reduced

Psilotum Gametophyte

Subterranean (underground)

Mycorrhizal relationship - Gets help with nutrients by fungi

Fiddleheads

Fern leaves that starts tightly coiled and unravels due to circinate vernation

Sori

Groups of sporangia

1/3 of Ferns are epiphytic meaning?

They grow on trees

What are the 4 extent phyla of Gymnosperms

Conifers (Coniferophyta)

Cycads (Cacadophyta)

Ginkgos (Ginkgophyta)

Welwitchia (Gnetophyta)

Progymosperm Archaeopteris had everything but what

The seed

Gymnosperm

Seed isn’t in ovary, sporophyte produces ovule, extreme heterospory

Structures of an Ovule

Integument (2n) - Seed coat

Nucellus (2n)

Megasporocyte (2n) - creates megaspores(n)

Micropyle - Integument opening

Gymnosperm characteristics

Megaspores remain in the megasporangium

Megagametophyte develops in megaspore(non-free-living)

Development of the embryo inside the megagametophyte

What is a seed

Embryo (sporophyte) (2n)

Megagametophyte(n) - Stored food

Seed Coat (2n) - Old sporophyte

Out of the species we talked about which is the most endangered?

Gymnosperms are the most endangered

Structures of Leaf

Waxy Cuticle

Sunken Somata

Epidermis

Hypodermis - Under epidermis

Endodermis

Mesophyll

The endodermis in a leaf does what

Connects the vascular tissue to the mesophyll

The mesophyll in a leaf does what

Photosynthetic area, also increases surface area

Why needles for gymnosperms?

Low surface area to volume ratio (For water retention and easier maintenance)

Adaptations to cold and drought

Almost every major period of plant growth is followed by what

An Ice age

How are gymnosperms adapted to fire

Serotinous cones (Fire opens them)

Thick Bark

Self Pruning Branches

Center part pine stem and function

Pith, for storage

Why do gymnosperms not require water for fertilization?

because pollen(microspore) transports the microgametophyte to the megaspore, microgametophyte digest a pollen tube that connects to the egg, and the sperm once their generates to fertilize

What does each microspore develop into

One pollen grain

How much sperm is created by generative cell

2 are created

Pollen grains are how many cells

4 cells

Cones take how long to mature

2 years, 12 months for pollen tube to reach egg

How much seeds per scale in a cone

2 seeds per scale

Uses of gymnosperms

Wood building material and paper, Turpentine and Pitch

First thing that is hit by pollen in Gymnosperms

Micropyle

First thing that is hit by pollen in Angiosperms

Stigma on the style

Two types of Agniosperms

Monocot and Dicot

Monocot

Single Cotyledon

Parallel Veins

Flower Parts in multiples of three

Dicot

Two cotyledons

Broad Leaf

Flower parts in multiples of 5 or 4

Types of ways Agniosperms get food

Autotrophs (Main way)

Parasitic

Mycoheterotrophic (Fungi nutrients)

Gionecium part of flower

Female part of flower that consist of Ovary, Stigma, Style

Flower receptacle

Where everything on the flower attaches to

Androecium part of flower

Male part of flower, Consist of multiple appedanges.

Filament and Anther

Inflorescence

A cluster or arrangement of flowers

What type of inflorescence is this

Spike, Flowers are directly attached to main stem

What type of inflorescence is this

Umbel, all flower stalks arise from the same point

What type of inflorescence is this

Panicle, Side branches come of main stem, and those branches bear flowers

What type of inflorescence is this

Head, many tiny flowers packed into one flower-like structure

What type of inflorescence is this

Catkin, look like fuzzy tails hanging from tree

Largest Infloresence

Amorphophallus titanum (Titan Lily)

Largest single flower

Rafflesia Arnoldi (Stinking corpse lily)

Hypogynous flower

Ovary located above flower parts