Evolution — BIOLOGY STD 12 Science — Question

What role does pituitary gonadotropins play during follicular and ovulatory phases of menstrual cycle? Explain the shifts in steroidal secretions.

Give a genetic explanation for the following cross. When a tall pea plant with round seeds was crossed with a dwarf pea plant with wrinkled seeds then all the individual of F₁-population were tall with round seeds. However selfing among F₁-population led to a 9:3:3:1 phenotypic ratio.

While living in and on the host species, the animal parasite has evolved certain adaptations. Describe these adaptations with examples.

Describe the species according to their susceptibility to extinction and the IUCN Red List.

In a court of law, two couples X and Y, claim a child Z of blood group O belongs to them. Couple X has man with blood group O and woman with blood group AB. Couple Y has man with blood group A and woman with blood group B. So, a geneticists helped in solving the problem but the judge ordered the= use of more recent and advance techniques and then the child was handed over ultimately to couple Y.

1. Is it a correct judgement regarding the true/ biological parents of the child? Justify with your knowledge of genetics.
2. Name the other technique that the judge has ordered for solving this problem.
3. Indicate the value(s) exhibited by the judge.

Answer the following questions:
Explain Polygenic inheritance and Multiple allelism with the help of suitable examples.

A child has blood group O. If the father has blood group A and mother blood group B, work out the genotypes of the parents and the possible genotypes of the other offsprings.

Fitness is the end result of the ability to adapt and get selected by nature. Explain with suitable example.

Ganga has recently been declared the national river. Discuss the implication with respect to pollution of this river.

What is Implantation? Describe the process of implantation with diagram.