CBSE 12TH BIOLOGY - Online Test
Q1.
Which of the following statements are correct about origin of earth?
a. There was no atmosphere on early earth.
b. Water vapour, methane, carbon dioxide and ammonia are released from molten mass covered the earth.
c. Oxygen gas is released from plants during photosynthesis.
Answer : Option C
Explaination / Solution:
There was no atmosphere on early earth. Water vapour, methane, carbon dioxide and ammonia are released from molten mass covered the earth. Oxygen and hydrogen gas is formed by splitting of water by UV rays.
Q2. Select the wrong pair of vegetative propoagules from the following pairs?
Answer : Option B
Explaination / Solution:
The wrong pair of vegetative propoagules is rhizome-potato. Potato is grown vegetatively by eyes present on underground modified tubers. Vegetative propagation is a mode of asexual reproduction.
Q3. Transducers is the term used for
Answer : Option A
Explaination / Solution:
Transducers are those organisms that convert one form of energy to another form. Green plants converts solar energy into chemical energy in foods by the process of photosynthesis.
Q4. Mobile genetic elements that replicate an RNA intermediate are called as
Answer : Option A
Explaination / Solution:
Mobile genetic elements that replicate an RNA intermediate are called transposons. It is a small piece of DNA that inserts itself into another place in the genome.
Q5. Identify mechanical contraceptive in figure below
Answer : Option A
Explaination / Solution:
Female condom is a mechanical contraceptive similar to condom used by male. It prevents the meeting of ovum with sperm as well as provide protection against STDs.
Q6. The outer most layer of maize endosperm is
Answer : Option A
Explaination / Solution:
Maize is monocotyledonous seed containing large amount of endosperm as reserve food. It is covered by a thin layer called as alurone layer. This layer is protective in nature.
Q7. Zone of Earth occupied by living organisms is called
Answer : Option B
Explaination / Solution:
The zone of earth occupied by living organism is called biosphere. It includes, lands, water and air where living organisms survive.
Q8. Which of the following drug is very effective sedative and painkiller?
Answer : Option C
Explaination / Solution:
Morphine is a very effective sedative and painkiller, and is very useful in patients who have undergone surgery.
Q9. Operon concept was given by
Answer : Option D
Explaination / Solution:
Jacob and Monod (1961) gave the concept of Operon model to explain the gene regulation in prokaryotes using simple experiments to grow E. coli in petriplates containing histidine, lactose or lactose and glucose in the medium.
Q10. The entire collections of plants/seeds having all diverse alleles for all the genes of a crop is called
Answer : Option B
Explaination / Solution:
The entire collections of plants, seeds, plant parts having all diverse alleles for all the genes of a crop is called germplasm collections. Different parts of plants are kept at different temperature.
