Class 12 Biology Model Paper 2 MCQs Test

1. A sea slug normally responds to being poked by curling up. After being poked repeatedly the slug no longer curls up. This is an example of:

2. The diagram shows a synapse. Heroin affects neurons. Which labeled part does the heroin directly affect?

3. Recalling your knowledge of epistasis based on the coat colour in Labrador retriever; find out the coat colour with genoptype Bbee.

4. Virologists have discovered how to put together a bacteriophage with protein coat of phage T2 and DNA of phage T4. If this composite phage were allowed to infect a bacterium, the phages produced in the host cell would have:

5. A paleontologist has recovered a bit of tissue from 500 years old preserved skin of an extinct bird. The researcher would like to compare DNA from the sample with DNA from a living bird. Suggest the technique that would be more useful for increasing the amount of DNA available for testing.

6. Shorter than average height, infertility, webbed neck, low hair line at the back of neck, abnormal bone development, larger than normal number of moles on skin and edema indicates:

7. The primary organizer during embryonic development:

8. A biochemist isolated and purified molecules needed for DNA replication. When he added some DNA, replication occurred, but the DNA molecules formed were defective. Each consisted of normal DNA strand paired with numerous segments of DNA, a few hundred nucleotides long. What had the scientist probably left out of the mixture?

9. Skeletal disease which cause immobility and fusion of vertebral joints is called:

10. Which one of the following events is likely to take place, if the nuclei from an 8-celled stage of an embryo are transplanted into enucleated eggs?

11. In a population that is in Hardy-Weinberg equilibrium, 16% of the individuals show recessive trait. The frequency of dominant allele in the population is:

12. Nitrogen cycle in nature is depicted in the following flowing flow chart.

13. Using product rule, what proportion of offspring from the genetic cross AaBbCc x AaBbcc are expected to be heterozygous at all three genetic loci, assuming that loci are unlinked?

14. How many different trinucleotides can be made using the DNA nucleotides?

15. According to the semi-conservative model of DNA replication, two DNA molecules result:

16. The table show different endocrine glands with their hormones, target organs and brief functions. Identify the mismatched row.

17. Following graph show the concentration changes of different hormones during menstrual cycle. Name the hormone represented by “X”.