Science

Correct answer: A

I is incorrect: Phloem → Transport of sugars and other organic solutes. It carries products of photosynthesis between plant organs. II is incorrect: Vaccine → Preparation that induces immune memory. It prepares immune responses without requiring the full natural disease.

Correct answer: C

One sperm fuses with the egg and another with the central cell nuclei.

Correct answer: B

I is correct: Binary fission → Asexual division into two daughter organisms. It is common in bacteria and some unicellular eukaryotes. II is correct: Synapse → Junction for communication between neurons or with an effector. Signals commonly pass using neurotransmitters.

Correct answer: D

It processes proteins and lipids for transport.

Correct answer: A

I is correct: Adrenaline → Hormone supporting a rapid stress response. It can increase heart rate and mobilise stored energy. II is incorrect: Alveoli → Gas exchange in lungs. Their thin walls and large total area facilitate diffusion.

Correct answer: B

The membrane regulates entry and exit of substances.

Correct answer: A

I is incorrect: Double fertilisation in flowering plants → Formation of zygote and endosperm through two fusion events. One sperm fuses with the egg and another with the central cell nuclei. II is correct: Pollination → Transfer of pollen to a receptive stigma. It precedes fertilisation in flowering plants.

Correct answer: B

It is common in bacteria and some unicellular eukaryotes.

Correct answer: D

I is correct: Antibody → Protein that binds a specific antigen. It is produced by differentiated B cells. II is incorrect: Thyroxine → Hormone involved in metabolic regulation. Its synthesis requires iodine.

Correct answer: C

They help roots take up water and minerals.

Correct answer: A

I is incorrect: Antibiotic → Drug acting against susceptible bacteria. It does not directly treat ordinary viral infections. II is incorrect: Haemoglobin → Oxygen transport in red blood cells. The iron-containing protein binds oxygen reversibly.

Correct answer: B

It promotes cellular uptake and storage of glucose.

Correct answer: D

I is correct: Golgi apparatus → Modification and packaging of cellular products. It processes proteins and lipids for transport. II is incorrect: Vaccine → Preparation that induces immune memory. It prepares immune responses without requiring the full natural disease.

Correct answer: A

Signals commonly pass using neurotransmitters.

Correct answer: D

I is correct: Plasma membrane → Selective exchange with the surroundings. The membrane regulates entry and exit of substances. II is correct: Root hairs → Increase surface area for absorption. They help roots take up water and minerals.

Correct answer: B

It does not directly treat ordinary viral infections.

Correct answer: C

I is incorrect: Binary fission → Asexual division into two daughter organisms. It is common in bacteria and some unicellular eukaryotes. II is incorrect: Double fertilisation in flowering plants → Formation of zygote and endosperm through two fusion events. One sperm fuses with the egg and another with the central cell nuclei.

Correct answer: A

It is produced by differentiated B cells.

Correct answer: D

I is incorrect: Pollination → Transfer of pollen to a receptive stigma. It precedes fertilisation in flowering plants. II is incorrect: Haemoglobin → Oxygen transport in red blood cells. The iron-containing protein binds oxygen reversibly.

Correct answer: C

Its synthesis requires iodine.

Correct answer: A

I is correct: Synapse → Junction for communication between neurons or with an effector. Signals commonly pass using neurotransmitters. II is correct: Adrenaline → Hormone supporting a rapid stress response. It can increase heart rate and mobilise stored energy.

Correct answer: C

They help form a plug and participate in clotting processes.

Correct answer: A

I is incorrect: Ribosome → Protein synthesis. Ribosomes translate messenger RNA into polypeptides. II is incorrect: Root hairs → Increase surface area for absorption. They help roots take up water and minerals.

Correct answer: B

The iron-containing protein binds oxygen reversibly.

Correct answer: C

I is incorrect: Pollination → Transfer of pollen to a receptive stigma. It precedes fertilisation in flowering plants. II is correct: Vaccine → Preparation that induces immune memory. It prepares immune responses without requiring the full natural disease.