Biodiversity and Conservation — BIOLOGY STD 12 Science — Question

Discuss the relationship between detritus food chain and grazing food chain in a terrestrial ecosystem.

Both haemophilia and thalassemia are blood related disorders in humans. Write their causes and the difference between the two. Name the category of genetic disorder they both come under.

Explain the dual function of AUG codon. Give the sequence of bases it is transcribed from and its anticodon.

Explain how a hereditary disease can be corrected. Give an example of first successful attempt made towards correction of such diseases.

Even if a character shows multiple allelism, an individual will only have two alleles for that character. Why?

How do monocytes modify into macrophages?

Following table gives certain terms associated with ART. Fill in the spaces a, b, c and d.

VF and ET	a
b	Introduction of zygote/ embryo with 8 blastomeres into fallopian tube.
c	Introduction of ova of a donor into the fallopian tube.
d	Introduction of semen from the husband or healthy donor into the uterus.

What is the significance of adding proteases at the time of isolation of genetic material (DNA)?

A3' ............ 5'B
C5’ ........... 3'D.
AB and CD represent two strands of a DNA molecule. When this molecule undergoes replication, forming a replication fork between A and C in the above.

1. Name the templete strand for replication.
2. Using which strand as the templete, will there be continuous synthesis of a complementary DNA strand
3. Complementary to which strand will okazaki segments get synthesised, discontinuous synthesis occurs.
4. What are templete strands and Okazaki pieces?
5. In which direction is a new strand synthesised?