Lecture Exam 3 - plants and fungi

After fertilization

When do ovules become seeds

Embryo (sporophyte) and stored food

What does the seed contain

Seed coat

The protective layer around the seed made up of integuments

True

T/F - seeds are completely desiccated and can be dormant, yet alive, for many years

Cones

In seedless plants its strobili, in gymnosperms its _________

Sporophylls

Structure that bears sporangia which is where spores are produced

protection, store food, able to stay dormant

benefits of seeds

Heterosporus

Are seed plants homo or heterosporous

Wind and animals

2 main ways in which sperm gets to the egg in gymnosperms

Cones

Where are spores produced in gymnosperms

In the seed which are formed on teh scales of the ovulate cones

Where are embryos formed in gymnosperms

Within the ovule

Where do megaspores form in gymnosperms

Megaspore

A spore from a heterosporous plant species that develops into a female gametophyte.

Megasporangia (2n) - megaspore (n) - megagametophyte (n)

what does megasporangia ultimately develop (include ploidy)

Pollen

What do microspores produce

Microsporangia (2n) - microspore (n) - microgametophyte (n)

what does microsporangia ultimately develop (include ploidy)

False

T/F - Pollen is a fully developed gametophyte

Doesn't require water and can be transferred passively

What is the benefit of pollen i

Formation of the pollen tube that delivers the sperm to the egg

What happens when pollen is considered the fully developed gametophyte

nucellus

The megasporangium in seed plants

Seed

What does the ovule develop into after fertilization

Micropyle

A pore in the integuments of an ovule where pollen grains enter for fertilzation

1

How many integuments do gymnosperms have surrounding the nucellus

2

How many integuments do angiosperms have surrounding the nucellus

Micropyle

1

Integument

2

Megaspore

3

Megasporangium/nucellus

4

Retention of the megaspore

During the evolution of the ovule, what formed the nucellus

1

How many megaspore mother cells (2n) per megasporangium in gymnosperms

1

In gymnosperms, how many megaspores per sporangia survive

inside the megaspore

In gymnosperms, where does the female gametophyte form

Endosporic development

the gametophytes develop within the spore wall

In the female gametophyte within the maternal sporophyte

Where does the embryo develop

Fusion of integumentary lobes

What is the very general trend that caused the evolution of seeds

Progymnosperms

extinct fossilized remnants of the ancestors of gymnosperms

Progymnosperms

First woody plants, reproduced by spores, first evidence of eustele

Bifacial vascular cambium

What type of vascular cambium did progymnosperms have that allowed them to produce wood

True

T/F - all gymnosperms and angiosperms are able to undergo secondary growth

Paraphyletic group

What type of phylogenetic relationship do gymnosperms, progymnosperms, pteridophytes, and bryophytes have

Naked seed

What does gymnosperm literally mean

During the dinosaurs

When did gymnosperms dominate the earth

Coniferophyta, Cycadophyta, Ginkgophyta, Gnetophyta

4 extant phyla of gymnosperms

Cycads

Palm like plants found in the tropics, have seperate ovulate and staminate cones, most evoltuionary ancient

Gingko

Have fan shaped decidious leaves, preserved in temple grounds in asia, seperate male and female plants, pollen tube can grow to be parasitic

Gnetophytes

Similar to angiosperms but still considered gymnosperms, have strobili similar to inflorescences, contain vessels, and double fertilzation

Coniferophyta

The most numerous, widespread, and ecologically important gymnosperm phyla

Fascicles

Bundles of pine needles that take about 2 years of growth

Determinate meristem

What type of meristems do pines have in their fasicles

Damage

When does the determinate meristem of a pine needle become indeterminate again

Small surface area on leaves, prevention of accumulation of snow, thick cuticle

What are some adaptations that pines have that allow them to live in cold or dry environments

Soft wood

What type of wood do conifers have that differ from angiosperms

xylem only has tracheids and phloem only have sieve elements

What differs with xylem and phloem of pines compared to angiosperms

Resin ducts

In pines, found in the ground or vascular tissue and contains a sticky phenolic compound to deter herbivores

Monoecious

having male and female reproductive organs in the same plant

Megasporangia and microsporangia are found on seperate cones but the same tree

What makes pines monoecious

To encourage outcrossing

Why are male cones typically on lower branches while female cones are on lower branches

Microsporangiate cones

Where are microsporangia?

Microspore mother cell

What does each microsporangium contain

4 haploid microspores

What does the microspore mother cell produce via meiosis

Winged pollen grain

What does each microspore develop into

2 prothallial cells, a generative cell, and a tube cell

The cells of a winged pollen grain

Remnants of gametophyte generation

Prothallial cell

Divides to make sperm

Generative cell

Forms pollen tube during fertilization

Tube cell

modified determinate branches called seed-scale complexes

If ovuliferous scales are not just simple megasporophylls, what are they?

Ovule on the top and sterile bract below

What is the structure of a pine scale

4 megaspores (3 will degenerate)

What does the megaspore mother cell (megasporocyte) produce after meiosis

endosporically

How does the megaspore mother cell develop into the megagametophyte in pines

The sporophyte tissue of nucellus and integument

What will surround the megaspore of a pine

Within the archegonia at the micropylar end

Where do the eggs/ova form

Far apart

In what orientation are ovulate scales to ensure they are open to accept pollen and exude pollen drops

Pollen drops

In pines, after pollen grains settle on a scale, this helps carry the pollen grain through the micropyle in contact with the nucellus

the pollen grain germinates to form the pollen tube

What happens after the pollen grain gets to the nucellus

One month

At what point in the pine timeline are megaspores produced in the pine

2 or 3 archegonia differentiate at the micropylar end

After about 15 months after pollination, what happens in pines

The generative cell divides to to give rise to a sterile cell and a spermatogenous cell which makes sperm

After one year, what happens that makes the microgametophyte mature

15 months

About how many months after pollination does fertilization occur in pines by rupturing the pollen tube and releasing sperm

True

T/F - its possible for there to be 2-3 archegonia and polyembryony in pines

2 sporophyte generations and a gametophyte generation (sporophyte in gametophyte in sporophyte)

What generations are present in the conifer seeds and in what order

Gametophyte tissues

What serves are a food reserve for the developing embryo in conifer seeds

Wollemi pine

What is the rarest plant in the world that happens to be a conifer

Seqouias and fire reproduction

What is a cool example of an adaptation that conifers have for reproduction

Redwoods

Example of a huge conifer

Embryo

1 - Identify the parts of the gymnosperm seed

Gametophyte

2- Identify the parts of the gymnosperm seed

Previous sporophyte generation

3 - Identify the parts of the gymnosperm seed

Stamen

1

Anther

2

Filament

3

Petal

4

Sepal

5

Receptacle

6

Ovary

7

Pistil/carpel

8

Style

9

Stigma

10

Parietal

Placentation type

Axile

Placentation type

Free central

Placentation type