CBSE 11TH BIOLOGY - Online Test
Q1. Which is the scientific name for wheat?
Answer : Option B
Explaination / Solution:
Wheat is a grass widely cultivated for its seed, a cereal grain which is a worldwide staple food.
There are many species of wheat which together make up the genus Triticum; the most widely grown is common wheat (T. aestivum).
Q2. Guard cells of stomata are thicker
Answer : Option C
Explaination / Solution:
The cells surrounding the stomata are called guard cells. The guard cells of inner side are thicker and that of outer side is comparatively thinner.
Q3. The single cotyledon of cereal grain is
Answer : Option A
Explaination / Solution:
In monocotyledonous seeds single cotyledon is called as scutellum. It is found in cereal grains like rice, wheat, maize and other monocots.
Q4. A farmer grows cucumber plants in his field. He wants to increase the number of female flowers in them. Which plant hormones can be applied to achieve this?
Answer : Option D
Explaination / Solution:
Ethylene promotes female flowers in cucumbers thereby increasing the yield.
Q5. Which disorder is caused due to wild contractions in muscles?
Answer : Option C
Explaination / Solution:
Tetany is caused due to rapid spasms (wild contractions) in muscle due to low Ca++ inbody fluid.
Q6. Both WBC and RBC are formed in the
Answer : Option C
Explaination / Solution:
In adults, both WBC and RBC are formed in the bone marrow that is located in long bones such as thighs.
Q7. Who demonstrated that the extract of the infected plants of tobacco could cause infection in healthy plants?
Answer : Option A
Explaination / Solution:
Beijerinek is considered one of the founders of virology. In 1898, he published results on the filtration experiments demonstrating that tobacco mosaic disease is caused by an infectious agent smaller than a bacterium and called the fluid as Contagiumvivum fluidum(infectious living fluid).
Q8. In diffusion, the movement of molecule across typical plant cell takes about
Answer : Option D
Explaination / Solution:
Long distance transport of substances within a plant cannot be by diffusion alone. Diffusion is a slow process. It can account for only short distance movement of molecules. For example, the movement of a molecule across a typical plant cell (about 50 μm) takes approximately 2.5 s.
Q9. Dark brown amorphous substance formed by degradation of cellulose and lignin in the soil to increase water holding capacity and aeration is
Answer : Option A
Explaination / Solution:
Dark brown amorphous substance formed by degradation of cellulose and lignin in the soil to increase water holding capacity and aeration is humus. It also increase fertility of the soil.
Q10. If an imaginary food contains 5 grams of protein, 4 grams of fat and 10 grams of carbohydrates. Now calculate total calories it would provide ( given 1g protein=4 calories, 1g fat = 10 calories, 1g carbohydrates = 4 calories ) :
Answer : Option B
Explaination / Solution:
Five gram of protein will produce 5 x 4 = 20 calories, 4 g of fat = 4 x 10 = 40 calories and 10 g of carbohydrates = 10 x 4 = 40 calories. So total energy produced is equal to 20 + 40 + 40 = 100 calories.
