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Living World | Botany - Answer the following questions | 11th Botany : Chapter 1 : Living World

Chapter: 11th Botany : Chapter 1 : Living World

Answer the following questions

Botany : Living World - Book Back and Important Questions Answers - Brief Questions Answers, Short Questions Answers

Diversity of Living World

Living World 

 

6. Differentiate Homoiomerous and Heteromerous lichens.

Homoiomerous

1. Here algae cells evenly distributed in the thallus

Heteromerous

1. Heteromerous-a distinct layer of alga and fungi present.


7. Write the distinguishing features of Monera.

Monera include - I. Archaebacteria II. Eubacteria.

I. Archarbacteria - It is primitive they are adapted to thrive in extreme environmental conditions

• Hot springs

• High salinity condition

• Absence of oxygen

• Low pH (high acidic condition)

• Their cell membrane is made up of lipids like glycerol and isopropylethers so resist high temperature and antibiotics.

II. Eubacteria - All other bacterial types are kept under the category. Eg. Pseudomonas

a. They are generally, prokaryotic, genetic material is called Nucleoid or genophore or incipient nucleaus -Unicellulaar

b. Cellwall is made up of polysaccharide & protein

c. Based on nutrition

i. Heterotrophic - 1. Saprophylic - E.g. Agrobacterium

2. Parasitic - E.g. Vibrio cholera

ii. Autotrophic - Have bacteria with Bacterio chlorophyll- e.g. chromatium.

d. Motility - Motile or non motile


8. Why do farmers plant leguminous crops in crop rotations/mixed cropping?

Rhizobium- Nitrogen fixing bacteria,

Living in the root modules of leguminous plants has symbiotic association with it, fix atmospheric nitrogen and convert it in to nitrates, there by increases the fertility of the soil.

Growing legumes alternatively with paddy can help paddy to give high yield- This method of growing paddy, alternatively with leguminous plants is known as crop rotation.

Mixed cropping:

Amidst, other crops. Leguminous crop are also raised as mixed crop - so that it enriches the soil and increases the yield by fixing atmospheric nitrogen.


9. Briefly discuss on five Kingdom classification. Add a note on merits and demerits.

a. Proposed by R.H. Whittaker (American taxonomist)

b. Criteria considered - cell structure, Thallus Organization, Mode of Nutrition, Reproduction, and Phytogenitic Relations.

5 kingdom classifications include: -

a. Monera

b. Protista

c. Fungi

d. Plantae

e. Animalia


Merits:

1. Based on complexity of cell structure & organization of thallus

2. Based on mode of nutrition.

3. Fungi-kept in a separate category from plants

4. It shows the phylogeny of the organisms

Demerits:

1. Monera & Protista - Include both autotrophic & hetrotropic organisms

2. Include cell wall lacking & cellwall

3. Bearing organisms.

4. So the group is more heterogeneous


10. Give a general account on lichens.

a. Definition: A symbolic association of algae and Fungi helping each other & living together known as lichens.

b. Partners: Algal partner known as Phycobiont & Fungal partner known as Mycobiont

c. Role of Algal partner - Autotrophic prepare food - give nutrition to fungal partner also

d. Role of fungal partner - gives protection- helps in fixing to the substratum by rhizinae. 

Classification:

1. Character of Asexual reproduction

Phycobiont : Akinetes, hormogonia, Aplanospore etc.

Mycobiont : fragmentation soredia, and isidia

2. Character of Sexual reproduction

Phycobiont : absent

Mycobiont : sexual reproduction by ascocarp & ascospores

1. Character : Habitat

Classification of lichens:

Corticolous - growing on bark

Lichnicolous - growing on wood

Saxicolous - growing on rock

Terricolous - growing on ground

Marine - siliceous rock sea

Fresh water - siliceous rocks (fresh water habitat).

2. Character : Morphology of thallus

Classification of lichens:

Leprose - distinct fungal layer absent

Crustose - crust like

Foliose - Leaf like

Fruticose-branched pendulous shrub like

3. Character : On the basis of distribution of algae cells

Classification of lichens:

Homoiomerous - Algae cells evenly distributed

Heteromerous - A distinct layer of Algae and Fungi present

4. Character :  On the basis of fungal partner

Classification of lichens:

If it is Asomycetes - Ascolichen

If it is basidiomycetes- Basidiolichen

Economic importance:

I. Secretion of acids of lichens

1. Oxalic acid Uses: Weathering of rocks Pioneers in xerosere

2. Usnic acid Uses: Antibacterial

II. a. Pollution Indicators - Lichens sensitive to air pollutants- (pollution indicators)

b. Rocella montagnei - Produces a dye used in litmus paper (acid base indicator)

c. Cladonia rangiferina - Food for animals in tundra regions


11. Explain the asexual reproduction in Rhizopus.

12. Mention the steps involved in the sexual reproduction of Rhizopus.

13. Write outline the life cycle of Agaricus.

14. What is Sterigma?

15. Name the types of mycelium found in Agaricus.

16. Differentiate oidium and Chlamydospore.

17. Name the fungal group which possess dolipore septum.

18. Mention the diseases caused by fungi in plants.

19. Give two examples for mycorrhizae forming fungi.

20. Differentiate Gram positive and Gram negative bacteria.


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