8th Science Guide Lesson 17 Plant Kingdom

8th Std Science Guide Lesson 17 Plant Kingdom | English Medium

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8th Science Guide Lesson 17 Plant Kingdom

I Fill in the blanks:

1. The word ‘Taxonomy’ is derived from ____________ Ans : Greek
2. Binomial Nomenclature was first introduced by ____________Ans : Gaspard Bauhin
3. The book “Genera Plantarum” was written by ____________ Ans : Bentham and Hooker
4. Monocotyledon seeds bear only ____________cotyledon. Ans : One
5. Brown algae belongs to ____________class. Ans : Phaeophyceae
6. Agar Agar is obtained from ____________ algae. Ans : Red
7. The reserve food material of fungi are ____________ and ____________ Ans : Glycogen and oil
8. The first true land plant is ____________ Ans : Pteridophyte
9. Xylem and phloem are absent in____________ plants. Ans : Bryophyte
10. Reticulate venation is present in ____________ plants. Ans : Dicot

II.Choose the correct answers:

1. Solanum trilobatum is the binomial name of Thoothuvalai. Here the word ‘Solanum’ refers to

1. Species
2. Genus
3. Class
4. Orders

Ans : Genus

2. ____________ is an example for colonial form of algae.

1. Oscillatoria
2. Nostac
3. Volvox
4. Chlorella

Ans : Volvox

3. Floridian starch is a reserve food material of ____________

1. Chloroplyceae
2. Phaeophyceae
3. Rhodophyceae
4. Cyanophyceae

Ans : Rhodophyceae

4. The edible mushroom is ____________

1. Polyporus
2. Agaricus
3. Pennicillium
4. Aspergillus

Ans : Agaricus

5. Soil erosion is prevented by____________ plants.

1. Algae
2. Fungi
3. Bryophytes
4. Pteridophytes

Ans : Bryophytes

6. The first vascular cryptogams in land plants are ____________

1. Bryophytes
2. Pteridophytes
3. Gymnosperm
4. Angiosperm

Ans : Pteridophytes

7. The well-developed sporophytic plant body is seen in

1. Bryophytes
2. Pteridophytes
3. Gymnosperms
4. Angiosperms

Ans : Pteridophytes

8. Binominal Nomenclature was first introduced in the year of ____________

1. 1970
2. 1975
3. 1978
4. 1623

Ans : 1623

 

9. Penicillin is an antibiotic, which is extracted from____________

1. Algae
2. Fungi
3. Bryophytes
4. Pteridophytes

Ans : Fungi

III True of False

1. In polypetalae, the petals are free.Ans : True
2. Binomial name should contains more than two words.Ans : False

Cu. st. : Binomial name should contain two words.

3. Artificial system of classification is based on the vegetative characters of the plant.Ans : False

Cu. st. : Artificial system of classification is based on the morphological characters of the plant.

4. Cell wall of fungi is made up of chitin.Ans : True
5. Pinus is a closed seeded plant.Ans : False

Cu. st. : Pinus is a naked seeded plant.

6. All bryophytes are hydrophytes.Ans : False

Cu. st. : All bryophytes are amphibians.

7. Dicotyledons have well developed characters than the monocotyledons.Ans : False

Cu. st. : Monocotyledons have well developed characters than the dicotyledons.

8. Mosses are the well developed plant in bryophytes.Ans :True
9. The dominant phase of the bryophytes is sporophytes.Ans : False

Cu. st. : The dominant phase of the bryophytes is gametophyte.

10. The dominant phase of the pteridophytes is diploid(2n).Ans : True
11. Seeds of angiosperm are produced inside the ovary.Ans : True
12. In gymnosperms ovules are developed from the flowers.Ans : False

Cu. st. : In gymnosperms ovules are developed from the cones

IV. Match the following

1. Which of the following pairs are in correct?

1. Laminaria – Iodins
2.  Nostoc – N2 fixation
3. Polysiphonia – Green algae
4. Rhodophyceae – Fucoxanthin

a) a, b, c

b) c, d

c) a, c, d

d) a ,b ,c, d

Ans : c, d

2. Find out the correct pairs:

1. Phyllanthus amarus – Euphorbiaceae b. Solomum trilobatum – Solanaceae
2. Acalypha indica – Malvaceae d. Aegle marmelos – Rutaceac
3. a, b
4. c, d
5. a, b, c
6. a, b, d

Ans : a, b, d

3. Which of the following characters are not suitable to angiosperm?

1. a) Reticulate / parallel venation, closed seeded plants, sieve tubes are present in phloem.
2. b) Seeds are open, ovary is not present, gametes are produced in coneS.
3. c) Tracheids are the conducting cells, companion cells not are present in phloem.
4. d) Trimerous or tetramerous, closed seed, seed with seed coat, bears fruit.
5. a, b
6. b, c
7. e, d
8. a, d

Ans : b, c

4. Which of the following sequences are correct

1. a) In Bryophytes – Gametophytes – Sex organ – Gamete fusion – Zygote – Spore mother cell – spore – Thallus.

b ) In Angiosperm – pollination – fertilization – zygote – new plant.

1. c) In Gymnosperm – male cone, and female cone – microspore and megaspore – Zygote – new sporophytes plant.
2. d) In pteridophytes – pollination by wind, fertilization in the presence of water – zygote prothallus, new plant.
3. a, b, c
4. a, b
5. c, d
6. b, d

Ans : a, b, c

5. Match column I with coloumn II

1. Penicillium chrysogenum – Blast disease of paddy.
2. Ginko biloba – Ornamental plants
3. Araucaria bidwilli – Athlet foot
4. Tinea pedis – Penicillin
5. Pyricularia oryzae – Living fossil

Ans : 1 – d, 2 – e, 3 – b , 4 – c, 5 – a

V Assertion and Reason

1. Assertion (A) : Penicillin is an antibiotic extracted from Penicillium notatum.

Reason (R) : It can kill (or) inhibits the growth of the other micro organism.

1. Both A and R True, R explains A
2. A only correct, R doesn’t explain A
3. A True, R explains A
4. Both A and R False.

Ans : Both A and R True, R explains A

2. Assertion(A) : Artificial system of classification is otherwise called sexual system of classification.

Reason(R) : Artificial system of classification is based on the nature of the vegetative characters.

1. Both A and R correct
2. Both A and R incorrect
3. A is correct R is incorrect
4. A is incorrect and R is correct

Ans : A is incorrect and R is correct

3. Assertion(A) : Bryophytes are called Amphibians of the plant kingdom.

Reason(R) : Bryophytes are land plants but they need water for the completion of their

life cycle.

1. Both A and R correct
2. Both A and R incorrect
3. A is correct R is incorrect
4. A is incorrect and R is correct

Ans : A is correct R is incorrect

VI. Answer the following questions shortly

1. Define Thallus.

• The Plant body of algae are called thallus. i.e the plant body is not differentiated into root, stem and leaf.

2. What is mean by Binomial Nomenclature? Give example.

• The naming of an organisms with two words are known as Binomial Nomenclature. For
• example, the binomial name of mango is Mangifera indica. Here the first word Mangifera refers to the genus name and the second word indica to the species name.

3. Write any two points of dicotyledons.

• Seed has two cotyledons.
• Plants have tap root system, leaves with reticulate venation.

4. Seeds of gymnosperm plants are naked. Why?

• In gymnosperms, ovules are borne on megasporophylls and no flowers are produced. Therefore the seeds are described as naked. They are open seed bearing plants.

5. Write any two economic importance of fungi.

Antibiotic

• Pencillin (pencillium notatum) Neomycin, Gentamycin, Erythromycin are some antibiotics obtained from fungi, which are variable diseases.

Food

• Mushroom contains rich protein and minerals. The most common edible mushroom is Agaricus. (Button mushroom)

 

VI. Answers the following questions in brief

1. Write short notes about natural system of classification.

• In this system, plants are classified on the basis of several characters. Bentham and Hooker’s classification is an example of Natural System of Classification.
• This system of classification is based on morphological.
• This classification is widely used in many Herbaria and botanical gardens all over the world.
• Bentham and Hooker published their Natural system of Classification in their book named Genera Plantarum in 3 volumes.

2. Write any three economic importance of algae.

Agriculture

Some of the blue green algae are essential for the fixing of atmospheric nitrogen into the soil, which increases the fertility of the soil,

example Nostoc, Anabaena.

Agar Agar

Agar Agar is extracted from some red algae, namely Gelidium, Gracillaria, etc., which is used to prepare growth medium in laboratories.

Iodine :

Iodine is obtained from brown algae like Laminaria (kelp).

3. Write the differences between algae and fungi.

Algae:	Fungi
1. Algae are autotrophs.	Fungi are heterotrophs.
2. It has pigments.	It has no pigments
3. Reserve food material is starch.	Reserve food materials are glycogen and oil.
4. Some algae are prokaryotic in nature,	All are eukaryotic nature,
example: Cyanobacteria (Nostac, Anabenae)	example: Agaricus

4. How many classes are there in Bryophytes? What are they?

Bryophytes are classified into 3 classes.

1. Class I:

• Hepaticae (Liverworts) Example: Riccia.

2. Class II:

• Anthocerotae (Homworts) Example : Anthoceros

3. Class III :

• Musci (Mosses) Example: Funaria

5. Write any four characters of pteridophytes.

• The main plant body is sporophytes, which is the dominant phase, differentiated into true root, stem and leaves.
• Sporophytes reproduce by means of spores. Spores are produced in sporangium.
• The sporangia bearing leaves are called sporophyll.
• Most of the plants produce only one type of spore, it may be either microspore or megaspore (homosporous).

8th Science Guide Lesson 17 Plant Kingdom

VII. Answers the following questions in detail

1. Draw the outline of Bentham and Hookers system classification.

Outline of Bentham and Hooker’s system of classification:

Seeded plants (Division):

1. Dicotyledonae (Class I)

Polypetalae (Sub class I)

• Thalamiflorae
• Disciflorae
• Caliciflorae

Synpetalae (Sub class II)

• Inferae
• Heteromerae
• Bicarpellatae

Monochlamydeae (Sub class III)

• Series 8 Family 36)

2. Gymnospermae (Class II) (3 families)

3.Monocotyledonae (Class III) (Series 8 Family 36)

2. Write any five differences between monocot and dicot plants.

Monocots	Dicots
1. Seeds have a single cotyledon.	Seeds have two cotyledons.
2. Leaves show parallel venation	Leaves show reticulate venation.
3. They have fibrous root system.	They have tap root system.
4. Flowers are trimerous.	Flowers are tetra or pentamerous.
Example : Paddy	Example : Mango

3. Write differences between Gymnosperm and Angiosperm.

Gymnosperm	Angiosperm
1. They reproduce by production of cones.	They produce flowers.
2. Pollination is by wind.	Pollination takes place by wind, water, insects etc.
3. They are naked seed bearing plants.	They are closed seed bearing plants.
4. The xylem lacks vessels and phloem lacks sieve tubes.	Xylem and phloem and well developed.
5. They have two phases in its life cycle. (Sporophyte & Gametophyte).	The sporophyte is the dominant phase. Gametophytic phase is much reduced in angiosperms.

4. Write the economic importance of Gymnosperms.

• Woods of many conifers are used in the paper industries, example Pinus, Agathis.
• Conifers are the sources of soft wood for construction, packing and plywood industry example Cedrus, Agathis.
• Turpentine is an essential oil used for paint preparation extracted from the resin of Pinus. It is also used medicinally for relief from pain and bronchitis etc.
• Seeds of Pinus gerardiana are edible.
• Ephedrine is an alkaloid extracted from Ephedra. It cures asthma and respiratory problems.
• Araucaria bidwillii is an ornamental plant.

5. Write the names of medicinal plants and explain their uses.

Kuppaimeni:

• The paste obtained from the leaves of this plant is used to cure the bums on the skin.
• The juice of this plant leaves is mixed with lemon juice to cure ringworm.

Vilvam:

• The unripe fruit of this tree is used to treat indigestion.
• It is used to cure chronic, diarrhoea and dysentery.

Thoodhuvalai:

• It belongs to the family solanaceae.
• The leaves and fruits of this plant cure cough and cold.
• It is widely used in the treatment of tuberculosis and bronchial asthma.

Keezhanelli

• The entire plant is used for the treatment of jaundice.
• It gives additional strength to human liver and used to treat other liver disorders.

Sothu katrazhai

• Leaves of this plant is used to cure piles and inflammations on the skin.
• It cures peptic ulcer.