Principles of Inheritance and Variation — BIOLOGY STD 12 Science — Question

Given alongside is an enlarged view of one microsporangium of a mature anther.
Name ‘a’, ‘b’ and ‘c’ wall layers.

An orchid plant is growing on the branch of mango tree. How do you describe this interaction between the orchid and the imango tree?

A true breeding tall plant is crossed with a true breeding dwarf plant. F, progeny is 100% tall and F, has tall : dwarf in the ratio 3 : 1.

1. Explain why F, shows only one type of parental phenotype.
2. Name the patterns of inheritance in which the ratio deviates from above. Also mention the deviated phenotypic ratio.

Intensely lactating mothers do not generally conceive. Is it true? If yes, explain the reason.

Collect 5 examples of palindromic DNA sequences by consulting your teacher. Better try to create a palindromic sequence by following base pairs rules.

What is amplification with reference to DNA fingerprinting?

A, B and D are three independently assorting genes with their recessive alleles a, b and d, respectively. A cross was made between individuals of AabbDD genotype and aabbdd. Explain the type of genotypes of the offspring produced.

Name a genus of baculovirus. Why are they considered good biocontrol agents?

"Genes contain the information that is required to express a particular trait." Explain.

Treatment of wastewater is done in a sewage treatment plant to make it less polluting. Explain the following with reference to this treatment process:
a. Primary sludge
b. Activated sludge
c. Anaerobic sludge digesters