MODEL PAPER 10 — BIOLOGY STD 12 Science — Question

Name and explain the types of barriers of innate immunity which involve histamine and prostaglandins.

The male fruit fly and female fowl are heterogametic while the female fruit fly and the male fowl are homogametic. Why are they called so?

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.

Draw a neat labelled sketch of a replicating fork of DNA.

Write name of group of bacteria that converts milk into curd. Explain the process. Write one other useful activity of this type of bacteria.

What is a test cross? How can it decipher the heterozygosity of a plant?

Who postulated an adapter molecule to link the genetic code and the amino acids? What are its functions?

Lantana and Eichhornia are examples of two weeds. How do they affect the ecosystem?

Write the function of adenosine deaminase enzyme. State the cause of ADA deficiency in humans. Mention a possible permanent cure for an ADA deficiency patient.