Answer the following questions

Diversity of Living World

Plant Kingdom 

5. Differentiate halpontic and diplontic life cycle.

6. What is plectostele? give example.

• It is aprotostelic subgroup where xylem surrounded by phloem

• In this condition, xylem plates alternates with phloem plates

 e. g. lycopodium clavatum

7. What do you infer from the term pycnoxylic?

• Secondary growth is also traced in gymnosperms, E.g. Cycas and Pinus.

• The wood may be compact with narrow medullary ray this condition known as Pycnoxlic seen in Pinus.

• It is opposite to Manoxylic condition which is seen in Cycas. 

8. Mention two characters shared by gymnosperms and angiosperms.

Gymnosperms

1. Seed bearing plants

2. Plant body is a sporophyte and it is dominant phase.

3. Stem show secondary growth.

4. Alternation of generation is present.

Angiosperms

1. Seed bearing plants

2. Plant body is a sporophyte and it is also the dominant phase

3. Stem show secondary growth only in dicots not in monocots.

4. Alternation of generation is present.

9. Do you think shape of chloroplast is unique for algae. Justify your answer?

Variation among the shape of the chloroplast is found in members of Algae. All other plants have common structure except chlorophyceal group of algae. Here is a list of shapes of chloroplasts and examples from chlorophycea.

Cup shaped - Chlamydomonas

Discoidal - Chara

Girdle shaped - Ulothrix

Reticulate - Oedogonium

Spiral - Spirogyra

Stellate - Zygnema

Plate like - Mougeoutia

10. Do you agree with the statement ‘Bryophytes need water for fertilization’? Justify your answer.

Being amphibians of plant kingdom they are simplest land inhabiting cryptogams and restricted to moist shady habitats. They need water for the male gametes to reach Archegonia to effect fertilization. So water is needed for completing their fertilization and their life cycle.

11. List the classes of algae.

12. Mention the pigments and storage food of Dinophyceae.

13. What are cap cells?

14. Name the flagellation found in the zoospore of Oedogonium

15. What is Nucule?

16. Differentiate nodal and internodal cells of Chara.

17. What are elaters?

18. What is protonema?

19. Where do we find false indusium?

20. Explain the internal structure of Cycas rachis.

21. Differentiate long and dwarf shoot.