Human Reproduction — BIOLOGY STD 12 Science — Question

(i) What is called immunity?
(ii) Write the difference between active immunity and passive immunity. (Sr. Sec. Board Exam., 2023)
(iii) Explain passive immunization. (iv) Make a labeled diagram of the stages of life cycle of Plasmodium in mosquito host.

Write about multiple allelism with suitable example.###Describe multiple albinism showing the inheritance pattern of blood groups in human beings.

Discuss the role of healthy ecosystem services as a prerequisite for a wide range of economic, environmental and aesthetic goods and services.

OR

Describe the advantages for keeping the ecosystem healthy.

In case of polyembryony, If one embryo develops from the synergid and another from the nucellus, which one is haploid and which is diploid? Describe polyembryony and also mention how can it be commercially exploited.

You have studied the story of Pepper moths in England. Had the industries been removed, what impact could it have on the moth population? Discuss.

Gene expression can be controlled with the help of RNA. Explain the method with an example.

(i) Write the name of the disease occurring as a result of point mutation.
(ii) Explain the lac operon.
(iii) Draw a labelled diagram of the lac operon.

A true breeding pea plant homozygous for axial violet flowers is crossed with another pea plant with terminal white flowers (aavv).
What would be the phenotype and genotype of F₁ and F₂ generations?

Describe the functions of the following:
Trophoblast.

Explain the process of transcription in prokaryotes.