3. Review the alternation of generations diagram you did last week in discussion

ID: 163281 • Letter: 3

Question

3. Review the alternation of generations diagram you did last week in discussion. Where on this diagram does the angiosperm seed fit? Explain.

4. What 3 basic tissue systems are found in plants? What types of cells make up each of these tissue systems? What is the function of each cell and/or tissue type?

5. Differentiated cells have stopped dividing (passing through the cell cycle) and have become committed to forming a specialized cell type with a specific function. Examples of these in animals are muscle and nerve cells; in plants, petal and hair cells, and conducting cells in the xylem and phloem.

While adult animals generally have very few remaining undifferentiated cells (e.g. stem cells), plants carry "pockets" of undifferentiated material throughout their lifetime.

Where can these "pockets" of undifferentiated cells be found?

3:59 Ooo AT&T; 67% uwmad.courses.wisconsin. edu (I to 130 witn you to aiscussion. 1. Refer to both your text book and your lecture notes and complete the chart of "Land Plant Characteristics" below. CHARACTER PTEROPHYTES: Seedless vascular GYMNOSPERMS ANGIOSPERMS Free swimming microspores and pollen Microspores and pollen Egg protected in YES YES YES Megaspores and embryo sac (8 multicelled cell structure) structure (archegonium) Photosynthesis Gametophyte dominant I life dominant in life gametophyte both Waxy cuticle 2. Use the chart of land plant characteristics you developed to answer the following questions. a. What characteristics are common among all plants? b. What evolutionary changes are evident in plant structure and function as we look across these major groups of plants from Bryophytes (e.g. mosses) to Angiosperms? c. Until the evolution of the seed plants, land plants were dependent on the availability of water for reproduction. Explain why this was true. Explain how seed plants overcame the need for water in reproduction.

Explanation / Answer

Bryophytes

Pteridophytes

Gymnosperms

Angiosperms

Photosynthesis

yes

Pollen

Yes

Ovules

Yes

Ovaries

yes

Seed

Yes

Flower

Yes

Fruit

yes

Alternation generaion

Yes

yes

Yes

Gametophytic :Dominant

yes

Sporophytic: Dominant

Yes

yes

Sporpphytic, Gametophytic independent

Yes

Waxy cuticle

Yes

yes

Vascular tissue

Yes

Lignin

Yes

yes

Yes

ANSWER:

i. Photosynthesis

ii.Alternation of generation :Presence of sporophytic and gametophytic phase

i.Development of vascular tissue to provide mechanical support and as conducting tissue.

ii.Enclosed embryo inside seed.

iii.Better dispersal mechanisms of seed through fruit.

iv.Development of lignin as a chemical for protection and rigidity.

I.Dependency on wind for pollination (Gymnosperms)

II.Dependency on varied pollinating agents (Angiosperms)

3. DIAGRAM NOT SHOWN

4. 3 basic tissues in plants are :

Cells Types and tissue type function:

Function: Photosynthesis, food storage, regeneration, protection

3. Vascular Tissue: Parenchyma, Sclerenchyma and dead tissue

Function: Conduction of material and mechanical support

5. Pockets of unifferentaited cells in plants can be foun in all meristemtaic zones. These are present as:

a. Apical meristem (at tips of shoot nad root)

b. Interalary Meristem

c. Lateral Meristem