CBSE 12TH BIOLOGY - Online Test
Q1. In our society women are blamed for producing female children as the growth and development of child occurs inside the mother womb. This statement is
Answer : Option B
Explaination / Solution:
Women are not responsible for sex of child because they produce only one kind of gamete containing X-sex chromosome, on the other hand male produce two kinds of sperms half containing X and half Y sex chromosome.
Q2. Human insulin is being commercially produced from a transgenic species of
Answer : Option C
Explaination / Solution:
Human insulin is artificially prepared chemicals used by diabetic patients. This hormone is obtained from genetically engineered Escherichia bacterium that can reproduce rapidly.
Q3. In which conference held in 1997, the rich nations have agreed to limit the emission of green house gases.
Answer : Option C
Explaination / Solution:
The Kyoto Protocol was adopted in Kyoto, Japan, on 11 December 1997
The Kyoto Protocol is an international agreement linked to the United Nations Framework Convention on Climate Change, which commits its Parties by setting internationally binding emission reduction targets.
Recognizing that developed countries are principally responsible for the current high levels of GHG emissions in the atmosphere as a result of more than 150 years of industrial activity, the Protocol places a heavier burden on developed nations under the principle of "common but differentiated responsibilities."
Q4. EtBr is a mutagen as
Answer : Option A
Explaination / Solution:
EtBR or Ethidium Bromide is widely used nucleic acid stain and very strong mutagen and carcinogen. It causes mutation that cause variation or introduction of new traits.
Q5. The animals of cold countries have relatively shorter and poorly developed ear, eyes, hair and other phenotypic characters. This is known by which law?
Answer : Option B
Explaination / Solution:
Allen's rule. The principle holding that in a warm-blooded animal species having distinct geographic populations, the limbs, ears, and other appendages of the animals living in cold climates tend to be shorter than in animals of the same species living in warm climates.
The animals of cold countries have relatively shorter and poorly developed ear, eyes, hair and other phenotypic characters to avoid cold condition.
Q6. The metabolic process which causes a reduction in gross primary production:
Answer : Option A
Explaination / Solution:
Respiration causes a reduction in gross primary productivity of an ecosystem. Gross primary productivity – Respiration = Net primary productivity.
Q7. Viral infection can be treated by
Answer : Option D
Explaination / Solution:
Interferons can be sued to treat viral infection as interferon are proteins made and released by host cells in response to presence of pathogen as viruses, bacteria or tumor cells.
Q8. Identify the figure of the contraceptive used for birth control
Answer : Option C
Explaination / Solution:
The birth control implant is a thin, flexible plastic implant about the size of a cardboard matchstick. It is inserted under the skin of upper arm. It protects against pregnancy for up to three years.
Q9. Statement I: Seed is the basis of agriculture.
Statement II: Dehydration and dormancy of mature seed is crucial for storage of seeds.
Statement III: Seeds of rice and wheat remain viable for several years at normal condition.
Statement II: Dehydration and dormancy of mature seed is crucial for storage of seeds.
Statement III: Seeds of rice and wheat remain viable for several years at normal condition.
Answer : Option A
Explaination / Solution:
Seed is the basis of agriculture. Before storage, seeds are dehydrated in sunlight. Seeds remain dormant till the favorable condition is present. Seeds of wheat and rice remain viable only few years.
Q10. In deep lakes;littoral,limnetic and profundal zones represent:
Answer : Option C
Explaination / Solution:
In deep lakes differenet zones are formed according to availabilityof light, food and temperature. These zones are called littoral, limnetic and profundal zone. It is a kind of community stratification or separation.
