Human Health and Disease — BIOLOGY STD 12 Science — Question

What is the difference between transcription in prokaryotic and eukaryotic cells? Compare.

Answer the following questions:
Give a schematic representation of oogenesis in human female indicating the chromosomal number at each step. Mention at what stage of female life does each phase occur.

State and explain with the help of a cross, the law of segregation as proposed by Mendel.

With a neat, labelled diagram, describe the parts of a typical angiosperm ovule.

Rose plants produce large, attractive bisexual flowers but they seldom produce fruit. On the other hand, Lady’s finger produces plenty of fruits. Analyse the reasons for failure of fruit formation in rose.

Microbes can be used to decrease the use of chemical fertilisers and pesticides. Explain how this can be accomplished.

Enumerate the events in the ovary of a human female during:
Luteal phase of menstrual cycle.

Explain the embryonic development upto blastula formation in human ?###Draw a labelled diagram of blastocyst formation.###Define Cleavage ? Explain the development of the zygote upto blastocyst formation.

A true breeding pea plant homozygous for axial violet flowers is crossed with another pea plant with terminal white flowers (aavv).
List the Mendel’s generalisations that can be derived from the above cross.

How do ecologists estimate the total number of species present in the world?