CBSE 11TH BIOLOGY - Online Test
Q1. Which of the following is responsible for peat formation?
Answer : Option D
Explaination / Solution:
Sphagnum mosses not only dominate large areas of the boreal peatlands, but they have also formed these habitats by their growth and production of decay-resistant litter. As they invade, they can quickly transform a high-pH fen with little peat accumulation to a bog where large amounts of carbon is stored. They are also responsible for the many types of surface patterns observed in peatlands. Their ability to shape and transform mires can to a large extent be understood from the peculiar anatomy and biochemistry, a fact which makes the links between species’ traits and ecosystem functions in peatlands very strong.
Q2. Arrangement of ciliary microtubules is
Answer : Option A
Explaination / Solution:
Cilia present in prokaryotic organisms consist of microtubules. These microtubules are arranged in 9+2 order in which 2 forms the center and 9 are arranged at periphery.
Q3. Paper chromatography is technique to separate
Answer : Option D
Explaination / Solution:
Separation of leaf pigments of any green plant through paper chromatography. A chromatographic separation of the leaf pigments shows that the colour that we see in leaves is not due to a single pigment but due to four pigments: Chlorophyll a (bright or blue greenin the chromatogram), chlorophyll b (yellow-green), xanthophylls (yellow) and carotenoids.
Q4. First step in the process of inspiration is :
Answer : Option A
Explaination / Solution:
Inspiration is the process of intake of oxygen from the surrounding. This is achieved by increasing the volume of thoracic cavity. Contraction of diaphragm relax the sternum that increae the thoracic cavity.
Q5. Shekhar is 3 years old and he lives in hilly areas. He has swollen neck :
i. He is suffering from goitre caused due to iodine deficiency which may lead to cretinism.
ii. Goitre may lead him to myxoedema and Grave’s disease in future.
i. He is suffering from goitre caused due to iodine deficiency which may lead to cretinism.
ii. Goitre may lead him to myxoedema and Grave’s disease in future.
Answer : Option B
Explaination / Solution:
The persons living in hilly areas generally suffer from goiter disease. Goiter is caused due to iodine deficiency which may leads to cretinism. Goiter never leads to myxedemaor hypothyroidism.
Q6. Animals which possess cleidoic egg exhibit
Answer : Option D
Explaination / Solution:
The cleidoic egg is the type of egg which reptiles and birds lays. These eggs exhibit internal fertilization and external development.
Q7. Arachidonic acid has
Answer : Option A
Explaination / Solution:
Arachidonic acid has 20 carbon atoms including the carboxyl carbon. Molecular formula- C20H32O2.
Q8. In animal cells, the first stage of glucose break down is
Answer : Option A
Explaination / Solution:
In animal cells, like muscles during exercise, when oxygen is inadequate for cellular respiration pyruvic acid is reduced to lactic acid by lactate dehydrogenase. The reducing agent is NADH+ and H+ which is reoxidised to NAD+ in both the processes.
Q9. The layer of heart pericardium which checks its overstretching and overfilling as well as also protects heart from mechanical injury is :
Answer : Option C
Explaination / Solution:
Pericardium is protective covering of heart. Pericardium is made of different layers to perform different functions. The layer of heart pericardium which checks its overstretching and overfilling as well as protects heart from mechanical injury is fibrous pericardium.
Q10. Which is not a function of leaves?
Answer : Option A
Explaination / Solution:
Leaves perform the function of photosynthesis, exchange of gases and transpiration to loose excess of water. Formation of new buds is not a function of leaves.
