Human Reproduction — BIOLOGY STD 12 Science — Question

Explain the increase in the numbers of melanic (dark winged) moths in the urban areas of post-industrialisation period in England.

Explain co-evolution with reference to parasites and their hosts. Mention any four special adaptive features evolved in parasites for their parasitic mode of life.

Describe three manners in which fertilisation of human ovum by a sperm can be prevented.

List the changes that the primary ooctye undergoes in the tertiary follicular stage in the human ovary.

Name the thin clear coat surrounding mammalian egg.

State Mendel’s principle of segregation.

Differentiate between:
Genetic diversity and species diversity.

Taking the example of white-winged moths and dark-winged moths of England in pre and postindustrialised era, explain evolution by natural selection.

OR

How can evolution by natural selection be explained by melanised moths before and after industrialisation in England?

OR

How did industrialisation play a role in Natural Selection of light and dark-coloured moth in England?

OR

What do these pictures (a) and (b) illustrate with reference to evolution? Explain.

Given below are the sequences of nucleotides in a particular mRNA and amino acids coded by it.
UUU AUG UUC GAG UUA GUG UAA
Phe - Met - Phe - Glu - Leu – Val
Write the properties of genetic code that can be and that cannot be correlated from the above given data.