Human Health and Disease — BIOLOGY STD 12 Science — Question

How does the sperm penetrate through the zona pellucida in human ovum?

List two factors that determine the vegetation and soil type of an ecosystem.

On which method the ELISA test is based.

What is the function of trophoblast in human embryo?

Give an example of a sex-linked recessive disorder in humans.

Write the possible genotypes, Mendel got when he crossed F₁ tall pea plants with a dwarf pea plant.

Write the role of histone protein in packaging of DNA in eukaryotes.

State a reason for the increased population of dark coloured moths coinciding with the loss of lichens (on tree barks) during industrialisation period in England.

State one reason why breast feeding the baby acts as a natural contraceptive, for the mother?

Name the stage of cell division where segregation of an independent pair of chromosomes occurs.