Biodiversity and Conservation — BIOLOGY STD 12 Science — Question

In peas, tallness is dominant over dwarfness, and red colour of flowers is dominant over the white colour. When a tall plant bearing red flowers was pollinated by a dwarf plant bearing white flowers, the different phenotypic groups were obtained in the progeny.
Tall, Red = 138
Tall, White = 132
Dwarf, Red = 136
Dwarf, White= 128
Mention the genotypes of the two parents and of the types of four off springs. in numbers mentioned against them.

There is only one possible sequence of amino acids when deduced from a given nucleotides. But multiple nucleotides sequence can be deduced from a single amino acid sequence. Explain this phenomena

Mention the effects of smoking on human health

Life originated from the earth's inorganic atmosphere in the past, but this no longer happens today. Give two reasons.

What is the role of baker’s yeast in the production of bread?

From which plants are the following medicines obtained? Just write the name.
(i) LSD, (ii) Caffeine, (iii) Opium, (iv) Cocaine, (v) Charas.

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?

A mRNA strand has a series of codons out of which three are given below:

1. AUG
2. UUU
3. UAG

1. What will these DNA codons be translated into?
2. What are the DNA codons that would have transcribed these RNA codons?

Mention the possible levels of regulation of gene expression in eukaryotes.

How do plants tide over stressful environmental conditions?