CBSE 12TH BIOLOGY - Online Test
Q1. Which ratio is constant for DNA
Answer : Option D
Explaination / Solution:
In DNA, adenine bind with thymine and guanine binds with cytosine. So, sum of adenine and guanine is equal to sum of thymine and cytosine.
Q2. Which of the following is not an ecological parameter:
Answer : Option D
Explaination / Solution:
ecological parameter is a variable, measurable property whose value is a determinant of the characteristics of an ecosystem.
Ecological parameter includes, biomass, energy and number of individual in the ecosystem. Stratification is not a part of ecological parameter because it can not be quantified.
Q3. Which of the following scientist’s name is not correctly matched with the theory by them?
Answer : Option C
Explaination / Solution:
The theory of inheritance of acquired traits is given by Weismann. Mendel gave the theories of inheritance that includes law of dominance, law of segregation and law of independent assortment.
Q4. If a sample area comprises of more number of taxonomically unrelated species, this will indicate
Answer : Option C
Explaination / Solution:
Richness is a measure of the number of different kinds of organisms present in a particular area.
A diverse sample area having more number of taxonomically unrelated species will indicate a more diverse sample area.
A sample area is used to know the diversity of a geographical area.
Q5. Pollen grains are formed inside the
Answer : Option D
Explaination / Solution:
Pollen grains are formed inside the anther. Stamen contains filament and anther. Inside the anther microsporogenesis process takes place to produce haploid pollen grains that forms male gametes.
Q6. The opening of vagina is often covered partially by a membrane called
Answer : Option B
Explaination / Solution:
Vagina is partially covered by a membrane called hymen. The hymen is generally torn during first coitus. It may be also broken due to active participation in sports like cycling and horse riding.
Q7. The physical expression or appearance of a character is called as
Answer : Option D
Explaination / Solution:
The physical appearance of a character is called as phenotype. The genetic make of individual is called genotype. Tallness, round, wrinkled, yellow etc. are physical appearance.
Q8. Which of the followings is also called sac fungi that live parasitically and in various habitats?
Answer : Option A
Explaination / Solution:
Ascomycetes is called as sac fungi that live parasitically and in various habitats. They are responsible for a number of fungal disease in plants.
Q9. Smog which doesn’t contain any secondary pollutants is
Answer : Option D
Explaination / Solution:
Classical smog does not contain any secondary pollutants. It is a mixture of fog, sulfur dioxide and coal smoke particulates. Photochemical smog is formed by chemical reactions of sunlight, nitrogen oxide and voltalic organic compounds in the atmosphere to form secondary pollutants.
Q10. Most of animals are unisexual but a few are bisexual too as
Answer : Option B
Explaination / Solution:
Most of animals possess either male or female reproductive organs, so unisexual except a few organisms like earthworm that contain both male and female reproductive parts in same individual.
