Seedless F11JC

8/3/2019 Seedless F11JC

1/13

2/5/2012

Investigative Discovery of

Seedless Plants


2/13

2/5/2012

This lab will investigate slides and live specimens inthe following groups of organisms

Pterophyta

Hepatophyta Bryophyta

Non-vascular

plantsLycophyta

Vascular

Plants

Chlorophyta(green algae)


3/13

2/5/2012

Green Algae

Most species found in freshwater

Some unicellular, some colonial, othersmulti-cellular

Some green algae live on shorelinesand are able to survive periodic drying

Protection of gametes (eggs and sperm) veryimportant

The descendents of ancient green algae thatsurvived and reproduced in such environmentscould extend their range into a newenvironment with few competitors


4/13

2/5/2012

Some green algae are thought to

be closely related to plants.

Mostly aquatic

Mostly terrestrial

- Complex,

multicellular

growth forms- Produce

gametangia

that aresimilar to

plantsFigure 17.1 Dolphin manual (modified)


5/13

2/5/2012

Adaptations Required to Survive and

Reproduce on Land

Minimize water loss

Obtain water and mineral nutrients from soil

Transport water and nutrients Support body

Dispersal mechanisms not dependent on water

Mechanisms to allow fertilization in the terrestrialenvironment

Gametangia

Promote out-crossing


6/13

2/5/2012

Alternation of Generations

Life Cycle


7/13

Ploidy Ploidy = number of copies of each

chromosome per cell.

I.e., diploid (2N) organisms have two

copies of each chromosome per cell,

haploid (1N) organisms have one copy

of each chromosome per cell

2/5/2012


8/13

8

Life Cycles and Cell Division

Two types of cell division occur in the lifecycles of eukaryotes: Mitosis and Meiosis

TheBottom-Line

Mitosis produces two genetically identicaldaughter cells that may be haploid or diploid butare always the same as parent cell

Meiosis produces four genetically distinct daughtercells that are always haploid (half the number of

chromosomes in the parent cell)


9/13

2/5/2012

PlantsDo It Differently

Sexual reproduction in ALL plants involvesTWO multi-cellular stages:

Sporophyte stage (2N)

produce spores (1N) by meiosisSpores start the gametophyte stage (1N)

Gametophyte stage (1N)

produce gametes (1N) by mitosis

Gametes fuse to form zygotes the startof the sporophyte stage (2N)


10/13

2/5/2012

Figure 29.6 Alternation of generations (sporic life cycle)


11/13

Seedless Non-vascularplants TheBryophytes

Hornworts (Anthocerophyta), liverworts (Hepatophyta), and mosses(Bryophyta)

All lack true vascular tissues Gametophyte phase (1N) predominant

fertilization requires water to produce zygote (2N)

Sporophyte (2N) nutritionally-dependent on

the gametophyte, 1N spores for dispersal,


12/13

Seedless VascularPlants

Pterophyta (ferns, whisk ferns, and horsetails); Lycophyta (club mosses, etc.)

Sporophyte (2N) is

predominant

1N spores for dispersal

Gametophyte (1N) is small(but nutritionally-

independent)

fertilization requires water

All producelignin in the

walls of some cells

All have true vascular tissues

(xylem andphloem)


13/13

2/5/2012

Begin discovering seedless

plants1. Look at all of the specimens indicated on the

Topic Card. Learn to recognize the groups of

organisms and various stages in their lifecycles.

2. Determine which specimens/structures youre

assigned to take pictures of and label. Take

those images.3. Take pictures of, and label, any

specimens/structures that you wish to help you

study for the lab practical.

Seedless F11JC

Documents