Download App

MODEL PAPER 5 — BIOLOGY STD 12 Science — Question

Rajasthan BoardEnglish MediumSTD 12 ScienceBIOLOGYMODEL PAPER 51 Mark
MCQ
Assertion (A): Decomposition process is slower if detritus is rich in lignin and cutin.
Reason (R): Decomposition is largely an oxygen requiring process.
  • A
    Both (A) and (R) are true and (R) is the correct explanation of (A).
  • B
    Both (A) and (R) are true, but (R) is not the correct explanation of (A).
  • C
    (A) is true, but (R) is false.
  • D
    (A) is false, but (R) is true.
✓

Answer

(b) : Both (A) and (R) are true, but (R) is not the correct explanation of (A).
Explanation: Both (A) and (R) are true, but (R) is not the correct explanation of (A).

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 "Assertion (A) & Reason (B) MCQ" from MODEL PAPER 5→MODEL PAPER 5 — all question types→BIOLOGY STD 12 Science question papers→Rajasthan Board STD 12 Science question papers→Rajasthan Board question paper generator→

Similar questions

Bt cotton is not:
  1. A GM plant.
  2. Insect resistant.
  3. A bacterial gene expressing system.
  4. Resistant to all pesticides.
→
DNA or RNA segment tagged with a radioactive molecule is called _________.
  1. Vector
  2. Probe
  3. Clone
  4. Plasmid
→
For two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.
  1. Both assertion and reason are true, and reason is the correct explanation of assertion.
  2. Both assertion and reason are true, but reason is not the correct explanation of assertion.
  3. Assertion is true, but reason is false.
  4. Both assertion and reason are false.
Assertion: Helobial endosperm is found in monocots.
Reason: Two chambers are formed in this endosperm.
→
Two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.
  1. Both assertion and reason are true and reason is the correct explanation of assertion.
  2. Both assertion and reason are true but reason is not the correct explanation of assertion.
  3. Assertion is true but reason is false.
  4. Both assertion and reason are false.
Assertion: Rhizobium forms nodules on the roots of legume plants.
Reason: Rhizobium fixes atmospheric nitrogen into organic forms which is used by the plant as nutrients.
→
For two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.
  1. Both assertion and reason are true, and reason is the correct explanation of assertion.
  2. Both assertion and reason are true, but reason is not the correct explanation of assertion.
  3. Assertion is true, but reason is false.
  4. Both assertion and reason are false.
Assertion: Cilia lining the fallopian tube helps to pick up and push the released ovum into the oviduct.
Reason: Cilia of fallopian tubes beat towards uterus.
→
For two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.
  1. Both assertion and reason are true, and reason is the correct explanation of assertion.
  2. Both assertion and reason are true, but reason is not the correct explanation of assertion.
  3. Assertion is true, but reason is false.
  4. Both assertion and reason are false.
Assertion: In human male, testis are extra abdominal and lie in scrotal sacs.
Reason: Scrotum acts as thermoregulator and keeps testicular temperature lower by 2ºC for normal spermatogenesis.
→
Two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.
  1. Both assertion and reason are true and reason is the correct explanation of assertion.
  2. Both assertion and reason are true but reason is not the correct explanation of assertion.
  3. Assertion is true but reason is false.
  4. Both assertion and reason are false.
Assertion: An organism which acts as herbicide is called bioherbicide.
Reason: Phytophthora palmivora is a mycoherbicide.
→
Two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.
  1. Both assertion and reason are true and reason is the correct explanation of assertion.
  2. Both assertion and reason are true but reason is not the correct explanation of assertion.
  3. Assertion is true but reason is false.
  4. Both assertion and reason are false.
Assertion: Champagne gives off bubbles.
Reason: Alcoholic content is 12-16% in champagne.
→
Directions: In the following questions, the Assertions (A) and Reason(s) (R) have been put forward. Read both the statements carefully and choose the correct alternative from the following:
Assertion: Phenylketonuria is a recessive hereditary disease caused by body's failure to oxidise an amino acid phenylalanine to tryrosine, because of a defective enzyme.
Reason: It results the presence of phenylalanine acid in urine.
  1. If both the assertion and the reason are true and the reason is a correct explanation of the assertion.
  2. If both the assertion and reason are true but the reason is not a correct explanation of the assertion.
  3. If the assertion is true but the reason is false.
  4. If both the assertion and reason are false.
  5. If the assertion is false but reason is true.
→
For question, two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.
  1. Both assertion and reason are true, and reason is the correct explanation of assertion.
  2. Both assertion and reason are true, but reason is not the correct explanation of assertion.
  3. Assertion is true, but reason is false.
  4. Both assertion and reason are false.
Assertion : Psychotropic drugs affect behaviour and mental activities
Reason: Tranquillizer, a psychotropic drug, decrease tension and anxiety.
→