Science (English Medium) कक्षा १२ - CBSE Question Bank Solutions for Biology

• Assertion: Ribosomal RNA is synthesized in the nucleus of the cell.
• Reason: It is translated with the enzyme RNA polymerase III.

Some organisms suspend their metabolic activities to survive in unfavourable conditions. Explain with the help of any four examples.

Give an example of a codon having dual function.

Angiosperms bearing unisexual flowers are said to be either monoecious or dioecious. Explain with the help of one example each.

A non biology person is quite shocked to know that apple is a false fruit, mango is a true fruit and banana is a seedless fruit. As a biology student how would you satisfy this person?

Describe the development of endosperm after double fertilisation in an angiosperm.

Draw a labelled mature stage of a dicotyledonous embryo.

Why does endosperm development preceeds that of zygote ?

Describe the development of an endosperm in a viable seed. Why does endosperm development precedes embryo development?

Why does endosperm development precede embryo development in angiosperm seeds?

Write the contributions of the following scientists in deciphering the genetic code.
George Gamow; Hargobind Khorana; Marshall Nirenberg; Severo Ochoa

Answer the following question.
State the importance of a Genetic code in protein biosynthesis.

Differentiate between the genetic codes given below:
Unambiguous and Universal

Differentiate between the genetic codes given below:
Degenerate and Initiator

A diploid female plant and a tetraploid male plant are crossed. The ploidy of endosperm shall be ______.

In angiosperms, triple fusion is required for the formation of ______.

If an angiospermic male plant is diploid and female plant tetraploid, the ploidy level of endosperm will be ______.

The endosperm of gymnosperms is ______.

Double fertilization leading to initiation of endosperm in angiosperms require ______.

One of the following is true with respect to AUG.