Organisation of Life

Samacheer Book Back Questions And Answers For Science Standard 8 “Organisation of Life“

I. Choose the best answer:
1. _____ is tough and thick white sheath that protects the inner parts of the eye.
a) Sclera
b) Conjunctiva
c) Cornea
d) Iris

2. _____ cells are specialised cells that can be transformed into any kind of cells.
a) Nerve
b) Stem
c) Heart
d) Bone

3. Maintenance of constant internal environment of the body is known as
a) homeostasis
b) homeophytes
c) homeokinesis
d) homeophilics

4. In the absence of oxygen, glucose is broken down in to _____.
a) lactic acid
b) citric acid
c) acetic acid
d) nitric acid

5. The process of air passing in and out the lungs is called _____.
a) inhalation
b) exhalation
c) breathing 
d) None of these

6. Osmosis is the movement of water molecules from
a) higher concentration to a region of lower concentration.
b) lower concentration to a region of higher concentration.
c) Both of these
d) None of these

7. The erythrocyte is placed in _____ solution which has lesser concentration of solutes and greater concentration of water than in the cytoplasm.
a) hypotonic
b) hypertonic
c) neutral
d) acidic

II. Fill in the blanks:
1. _____ is the structural and functional unit of living organisms.
2. The largest cell is egg of an _____.
3. _____ is a good example for anaerobic respiration.
4. _____ nerve is located at the end of the eyes behind the retina.
5. The size of the cells are measured in units of _____.

Answers:
1. Cell
2. ostrich
3. Fermentation
4. Optic
5. microns

III. Match the following:
1. Carbohydrates     A. CO₂, Water and Heat
2. Glucose                B. Amino acid
3. Protein                 C. Glucose
4. Amino acids         D. Cholesterol and other steroid
5. Fatty acids            E. Enzymes, hormone, protein

Answers:
1. C
2. A
3. B
4. E
5. D

IV. State true or false. If false, correct the statement:
1. In hypotonic condition, concentration of the external and the internal solution of the organism are same.
2. Diffusion is the movement of particles from an area of lower concentration to higher concentration.
3. Human beings are warm blooded in nature.
4. The larynx has fold of tissue which vibrate with the passage of air to produce sound.
5. Aqueous humour plays an important role in maintaining the shape of the eye.

Answers:
1. False (The concentration of external solution is less compared to concentration of internal solution of the organism)
2. False (Diffusion is the movement of particles from an area of higher concentration to lower concentration)
3. True
4. True
5. True

Visit Our YouTube Channel For More Free Videos: Click Here