Download App

Molecular Basis of Inheritance — BIOLOGY STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 ScienceBIOLOGYMolecular Basis of Inheritance5 Marks
Question
Study the flow chart given below and answer the questions that follow:
  1. S strain into mice mice die.
  2. R strain into mice → mice live.
  3. Heat killed S strain + live R strain into mice → A
  4. Heat killed S strain + DNase + live R strain → into mice B
  1. Name the organism and differentiate between its two strains, R and S, respectively.
  2. Write the results A and B obtained in steps (e) and (d), respectively.
  3. Name the Scientist who performed the steps (a), (b) and (c).
  4. Write the specific conclusion drawn from the step (d).
✓

Answer

  1. Streptococcus pneumoniae:
  1. R-cells are those cells that form rough colonies, without a capsule and are non-virulent, i.e., they did not cause pneumonia.
  2. S-cells are those cells that form smooth colonies, protected by a capsule and are virulent, i.e., they caused the disease, pneumonia.
  3. He showed that DNA is the transforming principle.
  1. A. Mice died of pneumonia. B. Mice lived and did not suffer from pneumonia.
  2. Frederick Griffith performed the steps (a), (b) and (c).
  3. This indicates that DNA is the transforming principle.
When DNase is added to the medium, the DNA of the heat-killed cells gets digested and is unable to carry out the transformation.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "5 Marks Questions" from Molecular Basis of Inheritance→Molecular Basis of Inheritance — all question types→BIOLOGY STD 12 Science question papers→Gujarat Board STD 12 Science question papers→Gujarat Board question paper generator→

Similar questions

Differentiate between incomplete dominance and co-dominance. Substantiate your answer with one example of each.
→
A pregnant woman who have had amniocentesistest was advised to undergo MTP. It was diagnosed by her doctor that the embryo she is carrying has an extra barr body.
  1. Name the syndrome which is likely to be associated with the embryo.
  2. Why was she advised to undergo MTP?
  3. Do you justify the statutory ban on amniocentesis in our country Give reasons.
→
How are Mendelian inheritance, polygenic inheritance and pleiotropy different from each other?
→
  1. State the objectives of animal breeding.
  2. List the importance and limitations of inbreeding. How can the limitations be overcome?
  3. Give an example of a new breed each of cattle and poultry.
→
What are recombinant DNA vaccines? Give two examples of such vaccines. Discuss their advantages.
→
Species diversity decreases as we move away from the equator towards the poles. What could be the possible reasons?
→
a. Where is microsporangium located in an angiosperm? State the functions of tapetum and the other three layers of microsporangium.
b. Describe the structure of the male gametophyte produced as a result of microsporogenesis.
c. State the functions of each part of the male gametophyte.
→
What is endosperm and how is it formed? Describe the various types of endosperm found in angiosperms.
→
Which methodology is used while sequencing the total DNA from a cell? Explain it in detail.
→
The following table shows certain diseases, their causative organisms and symptoms. Fill the gaps.
  Name of the Disease Causative organism Symptoms
i. Ascariasis Ascaris ________
ii. ________ Trichophyton Appearance of dry, scaly lesions on various parts of the body.
iii. Typhoid ________ High fever, weakness, headache, stomach pain, constipation.
iv. Pneumonia Streptococcus pneumoniae ________
v. ________ Rhino viruses Nasal congestion and discharge, sorethroat, cough, headache.
vi. Filariasis ________ Inflammation in lower limbs.
→