HSC Science Class 12 - Tamil Nadu Board of Secondary Education Question Bank Solutions for Biology (Botany and Zoology)

What is the vaccine? What are its types?

First cell of male gametophyte in angiosperm is

Arrange the layers of another wall from locus to periphery

Choose the correct statement(s) about tenuinucellate ovule

List any two strategy adopted by bisexual flowers to prevent self-pollination.

Discuss the steps involved in Microsporogenesis.

Restriction enzymes are

Consider the following statements:

1. Recombinant DNA technology is popularly known as genetic engineering is a stream of biotechnology which deals with the manipulation of genetic materials by man invitro
2. pBR322 is the first artificial cloning vector developed in 1977 by Boliver and Rodriguez from E.coli plasmid
3. Restriction enzymes belong to a class
   of enzymes called nucleases. Choose the correct option regarding the above statements

Which one of the following palindromic base sequences in DNA can be easily cut at about the middle by some particular restriction enzymes?

What are the enzymes you can use to cut the terminal end and internal phospho di ester bond of nucleotide sequence?

Name the chemicals used in gene transfer.

What is a restriction enzyme? Mention their type with a role in Biotechnology.

How will you identify a vectors?

Read the given statements and select the correct option.

1. Hydrophytes possess aerenchyma to support themselves in water.
2. Seeds of Viscum are positively photoblastic as they germinate only in presence of light.
3. Hygroscopic water is the only soil water available to roots of plants growing in soil as it is present inside the micropores.
4. High temperature reduces use of water and solute absorption by roots.

Read the given statements and select the correct option.

1. Loamy soil is best suited for plant growth as it contains a mixture of silt, sand, and clay.
2. The process of humification is slow in the case of organic remains containing a large amount of lignin and cellulose.
3. Capillary water is the only water available to plant roots as it is present inside the micropores.
4. Leaves of shade plant have more total chlorophyll per reaction centre, low ratio of chl a and chl b are usually thinner leaves.

Read the given statements and select the correct option.

Statement A: Cattle do not graze on weeds of Calotropis.

Statement B: Calotropis have thorns and spines, as a defense against herbivores.

In soil water available for plants is

The plant of this group are adapted to live partly in water and partly above substratum and free from water

Ophrys an orchid resembling the female of an insect so as to able to get pollinated is due to phenomenon of

A free-living nitrogen-fixing cyanobacterium which can also form a symbiotic association with the water fern Azolla