Biotechnology and its Applications — BIOLOGY STD 12 Science — Question

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 : Dendritic cells originate in the bone marrow.
Reason: Dendritic cells are found in neuron.

Assertion (A): Yeasts such as Saccharomyces cerevisiae are used in baking industry.
Reason (R): Carbon dioxide produced during fermentation causes bread dough to rise by thermal expansion.

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.

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: A bacterial cell with no restriction enzymes will be easily infected and lysed by bacteriophages.
Reason: Restriction enzymes catalyse synthesis of protective coat around bacterial cell that prevents bacteriophage attack.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion.
3. Assertion is correct but Reason is incorrect.
4. Both Assertion and Reason are incorrect.

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: Dodo, Passenger pigeon, Stellers sea cow have become extinct due to over exploitation.
Reason: Excessive exploitation of a species, whether animal or plants reduces size of its population so that it becomes vulnerable to extinction.

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: Restriction endonuclease recognises palindromic sequence in DNA and cuts them.
Reason: Palindromic sequence has two unique recognition sites Pst I and Pvu I recognised by restriction endonuclease.

Assertion (A): Decomposition process is slower if detritus is rich in lignin and cutin.
Reason (R): Decomposition is largely an oxygen requiring process.

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.

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: Head of sperm consists of acrosome and mitochondria.
Reason: Acrosome contains spiral row of mitochondria.

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: Man does not urinate and ejaculate at the same time.
Reason: Membranous and penile part of urethra forms the outflow pathway for the urine and for the seminal fluid.