Telangana Board Biology Class 12 Previous Year Papers 2019 with Solutions - Free PDF Download.
Telangana Board Class 12 Biology Previous Year Paper 2019
FAQs on Telangana Board (TSBIE) Previous Year Question Paper for Class 12 Biology 2019
1. Enumerate applications of plant tissue culture.
The method which is used to grow plants out of meristematic tissues, in sterile conditions, on a nutrient culture medium is known as plant tissue culture. It has various applications over traditional practices such as-
It produces exact copies of parent plants or clones which is desirable when we want parental traits in offspring.
Plants produced by this method complete their life cycle in a short period of time.
Plants can be produced even in the absence of seeds or sexual reproduction.
Regeneration of the whole plant from a single cell is possible.
Plants produced and disease free.
It is also a method of in-situ conservation of endangered species.
2. What are the steps involved in recombinant DNA technology?
The joining of DNA molecules from two different species to create a new offspring is a part of recombinant DNA technology. Various steps involved in recombinant DNA technology are-
Isolation of genetic material- it is the first step in recombinant DNA technology to isolate the desired DNA from the host. The DNA obtained should be purely informed free from other organelles of the cell. Various enzymes such as cellulase lysozyme acceptor are used to digest other macromolecules of cells. Finally, chilled ethanol precipitates DNA which is pulled out.
Digestion by restriction enzyme- restriction enzymes are often referred to as molecular scissors which cut DNA at specific locations. After cutting the DNA desired segment is obtained by electrophoresis, which involves movement of negatively charged DNA to positive electrodes. The different sized DNA molecules separate under an electric field.
Amplification using PCR- polymerase chain reaction is used to make multiple copies of the desired fragment in-vitro.
Ligation- the desired fragment of DNA is then ligated with a vector by the help of DNA ligase. It is then turned as recombinant.
Insertion into host- DNA is introduced into the host cell and this process is called transformation.
Isolation of recombinants- this is done by the help of marker genes.
3. What is chyme?
Chyme is the food that passes from stomach to duodenum after continuous churning of food by the action of stomach walls. It comprises food, water, HCL and various other enzymes.
4. Write the important characteristics of Chordata.
Chordates are characterized by the following-
Presence of notochord which provides skeletal support and develops into vertebral columns in vertebrates.
The dorsal hollow nerve cord develops into the brain and spine.
Pharyngeal slits present.
Post anal tail is extension of skeletal system.
