CBSE 12TH BIOLOGY - Online Test
Q1. Biogas is produced by
Answer : Option A
Explaination / Solution:
Biogas is mixture of gases like methane, hydrogen and oxygen. It is produced by anaerobic breakdown of biomass like animal dung, animal wastes etc. It is used as fuel in rural areas.
Q2. Which of the following is a wrong matched pair
Answer : Option B
Explaination / Solution:
Dystrophic lake have too low accumulation of dissolved nutrients to support abundant plant life so, they have very low productivity.
Q3. Apomixis means
Answer : Option D
Explaination / Solution:
Apomixis is modified form of reproduction in plants in which seeds are formed without fusion of gametes. The diploid cell of nucellus develops into an embryo giving a diploid seeds.
Q4. The first restriction endonuclease discovered was
Answer : Option C
Explaination / Solution:
The first restriction endonuclease discovered was Hind II. Hind II always cut DNA molecules at a particular point by recognizing a specific sequence of six base pairs. This specific base sequence is known as the recognition sequence of Hind II.
Q5. Which of the following bird will be called most successfully evolved?
Answer : Option A
Explaination / Solution:
An organism that lays 5 eggs, hatch the 5 eggs to reproduce 5 offspring can be considered as most evolved out of the other given condition. Least evolved organism lays more egg but produce only a few offspring.
Q6. Expand RIA
Answer : Option C
Explaination / Solution:
Radioimmunoassay (RIA) is a very sensitive in vitro assay technique used to measure concentrations of antigens (for example, hormone levels in blood) by use of antibodies. As such, it can be seen as the inverse of a radiobinding assay, which quantifies an antibody by use of corresponding antigens
Q7. The maximum growth rate occur in
Answer : Option A
Explaination / Solution:
Maximum growth of individuals occurs during exponential phase of growth. This phase is followed by stationary phase of growth.
Q8. Match the following:
column I
(i) Migrate
(ii) Suspend
(iii) Regulate
(iv) Conform
Column II
(a) hibernation and aestivation
(b) sweat it out
(c) inability to maintain a constant internal environment
(d) people going from Rajasthan to Kashmir during summer
(i) Migrate
(ii) Suspend
(iii) Regulate
(iv) Conform
Column II
(a) hibernation and aestivation
(b) sweat it out
(c) inability to maintain a constant internal environment
(d) people going from Rajasthan to Kashmir during summer
Answer : Option D
Explaination / Solution:
People going from Rajasthan to Kashmir during summer is a kind of migration. During hibernation and aestivation organism suspends life proceeses to minimum levels. To regulate the body temperature sweating occurs and inability to maintain consistent internal environment is called conformation.
Q9. Antibodies in our body are complex
Answer : Option B
Explaination / Solution:
Antibodies in our body are present in the blood in form of glycoproteins. They produce antigens in response to foreign particles to provide immunity against the pathogen.
Q10. DNA has equal number of adenine and thymine residues (A = T) and equal number of guanine and cytosine (G = C). These relationships are known as
Answer : Option A
Explaination / Solution:
Chargaff's rules states that DNA from any cell of all organisms should have a 1:1 ratio (base Pair Rule) of pyrimidine and purine bases and, more specifically, that the amount of guanine is equal to cytosine and the amount of adenine is equal to thymine.
