CBSE 12TH BIOLOGY - Online Test
Q1. Which of the following will be able to cope with greenhouse effect
Answer : Option A
Explaination / Solution:
Greenhouse effect causes increase in temperature of earth.
Warm-blooded animal species can maintain a body temperature higher than their environment. In particular, homeothermic species maintain a stable body temperature by regulating metabolic processes. The only known homeotherms are birds and mammals.
Homeotherms can tolerate high temperature. So, homeotherms will be able to cope with the effect of green house effect.
Q2. Which of the following is used as selectable marker?
Answer : Option D
Explaination / Solution:
The Ampicillin resistance gene is used as selectable marker as it prevents the growth of non-transformants cells and promotes the growth of transformants only
Q3. Vermiform appendix in man, nictitating membrane and wisdom teeth are
Answer : Option B
Explaination / Solution:
Vermiform appendix in man, nictitating membrane and wisdom teeth are vestigial organs of human beings. These organs are functional in our ancestors but in present human beings they have become functionless and only present as remain.
Q4. Dead parts of plants and animals that fall on the earth surface constitute
Answer : Option D
Explaination / Solution:
Dead parts of plants and animals that fall on earth surface constitute litter. These litter get decomposed due to action of microbes to form humus and release nutrients in soil.
Q5. Gene transfer in biotechnology can be done by
Answer : Option C
Explaination / Solution:
Gene transfer in biotechnology can be done by number of methods. Microinjection is the use of a glass micropipette to inject a liquid substance at a microscopic or borderline macroscopic level. The target is often a living cell but may also include intercellular space.
Microinjection is one of the best methods to transfer desired gene into suitable host.
Q6. Which of the following is mechanical barrier used for birth control
Answer : Option C
Explaination / Solution:
Diaphragm is mechanical barrier used for birth control. It is made up of rubber and prevents meeting of sperm and ovum.
Q7. In which of the following plants fruit contain larger number of seed
Answer : Option C
Explaination / Solution:
The number of ovule present in ovary determine the number of seeds produced inside the fruit. Mango and neem produce single seed in each fruit. Lemon contain a number of seeds but orchid contain many small size seeds.
Q8. Success of an organism in nature can be determined by
Answer : Option D
Explaination / Solution:
Success of an organism in nature can be determined by measuring population size and biomass of the organism. An organism having large number of species is more successful than those with lesser numbers.
Q9. Asexual reproduction is common in
Answer : Option D
Explaination / Solution:
Asexual reproduction is common in Protists and Monera. Both these kinds include organisms having single celled body. Binary and multiple fissions are generally followed for asexual mode of reproduction.
Q10. The incubation period of Hepatitis 'B' virus is
Answer : Option C
Explaination / Solution:
Incubation period is the time elapsed between exposure to a pathogenic organism, a chemical, or radiation, and when symptoms and signs are first apparent.
The incubation period of the hepatitis B virus is 75 days on average, but can vary from 30 to 180 days. The virus may be detected within 30 to 60 days after infection and can persist and develop into chronic hepatitis B.
