Important food plants like tomato, banana, and ________ have been produced on a commercial scale using micro-propagation.

[Biotechnology-and-its-Applications] [class-xii ]

• potato
• apple
• wheat
• rice
Correct Option: B  [ apple ]

Remark: Tomato, banana, and apple are examples of plants produced commercially via micro-propagation.

Scientists have successfully cultured meristems of banana, sugarcane, and ________ to obtain virus-free plants.

[Biotechnology-and-its-Applications] [class-xii ]

• tomato
• maize
• potato
• cotton
Correct Option: C  [ potato ]

Remark: Meristems of banana, sugarcane, and potato have been cultured successfully.

The binding of activated Bt toxin to midgut epithelial cells causes cell swelling and ________, leading to insect death.

[Biotechnology-and-its-Applications] [class-xii ]

• calcification
• migration
• lysis
• fusion
Correct Option: C  [ lysis ]

Remark: The activated toxin creates pores causing cell swelling and lysis.

The complementary dsRNA molecule in RNAi binds to mRNA, preventing its ________.

[Biotechnology-and-its-Applications] [class-xii ]

• replication
• transcription
• translation
• degradation
Correct Option: C  [ translation ]

Remark: dsRNA binds to mRNA, preventing its translation (silencing).

One source of the complementary RNA for RNAi could be an infection by viruses having ________ genomes.

[Biotechnology-and-its-Applications] [class-xii ]

• DNA
• RNA
• protein
• lipid
Correct Option: B  [ RNA ]

Remark: Viruses having RNA genomes can be a source of dsRNA that initiates RNAi.

Another source of complementary RNA for RNAi are mobile genetic elements (transposons) that replicate via an ________ intermediate.

[Biotechnology-and-its-Applications] [class-xii ]

• DNA
• RNA
• protein
• plasmid
Correct Option: B  [ RNA ]

Remark: Transposons replicate via an RNA intermediate, which can be a source of complementary RNA.

Transgenic animals are used to study the biological role of factors involved in growth, such as ________-like growth factor.

[Biotechnology-and-its-Applications] [class-xii ]

• estrogen
• insulin
• thyroxine
• adrenaline
Correct Option: B  [ insulin ]

Remark: An example provided is the study of insulin-like growth factor.

Transgenic animals are specially made to serve as ________ for human diseases to investigate new treatments.

[Biotechnology-and-its-Applications] [class-xii ]

• antigens
• models
• vectors
• reagents
Correct Option: B  [ models ]

Remark: Transgenic animals serve as models for human diseases.

Transgenic animals are made more ________ to toxic substances than non-transgenic animals for faster chemical safety testing.

[Biotechnology-and-its-Applications] [class-xii ]

• resistant
• insensitive
• sensitive
• tolerant
Correct Option: C  [ sensitive ]

Remark: They are made more sensitive to toxic substances for rapid results in chemical safety testing.

Some ________ standards are required to evaluate the morality of all human activities that might help or harm living organisms.

[Biotechnology-and-its-Applications] [class-xii ]

• legal
• economic
• ethical
• philosophical
Correct Option: C  [ ethical ]

Remark: Ethical standards are required to evaluate the morality of human activities regarding living organisms.