#biology practice question

BOTANY

A pollen grain containing one vegetative ll and one generative ll is described as:

Bicellular pollen grains contain one vegetative ll and one generative ll. The generative ll may later divide to form two sperm lls. This follows from latest NCERT 2026-27 principle explaining the concept clearly for NEET students in simple steps as per rationalized syllabus.

Ref: NCERT Biology Textbook - Latest Edition for Academic Session 2026-27 (Botany section, Rationalized Textbook for Class XI and XII), Chapter: Biology - Botany portion (Latest NCERT Textbooks for Academic Session 2026-27 -

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BOTANY

Which feature of the genetic code ensures that an amino acid can be coded by more than one codon?

Degeneracy of the genetic code means that multiple codons can specify the same amino acid. This follows from NCERT principle where the relation explains the outcome clearly for students in simple steps.

Ref: NCERT Biology Textbook for Class XI and XII (Botany section), Chapter: Morphology and Anatomy of Flowering Plants, Topic: Plant structure and tissue systems.

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ZOOLOGY

Which among the following is NOT a mode of HIV transmission?

HIV is not transmitted through casual contact like shaking hands; it spreads through blood, sexual fluids, and contaminated needles. This follows from NCERT principle where the relation explains the outcome clearly for students in simple steps.

Ref: NCERT Biology Textbook for Class XI and XII (Zoology section), Chapter: Biology - Zoology portion covering relevant system and function.

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Hormones - Protein Hormones and Regulation of Blood Glucose

Which biomolecule acts as a catalyst in biological reactions?

Enzymes, which are proteins, act as biological catalysts, speeding up reactions without being consumed.

Ref: NCERT Class 12 Chemistry > Chapter 14: Biomolecules > Topic: Enzymes - Nomenclature, Properties and Mechanism

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Hormones - Protein Hormones and Regulation of Blood Glucose

Which enzyme is a protein that speeds up hydrolysis of lactose?

Lactase, a protein enzyme, catalyzes the hydrolysis of lactose into glucose and galactose.

Ref: NCERT Class 12 Chemistry > Chapter 14: Biomolecules > Topic: Enzymes - Nomenclature, Properties and Mechanism

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Hormones - Protein Hormones and Regulation of Blood Glucose

Which protein is a hormone?

Insulin is a protein hormone that regulates blood glucose levels by facilitating glucose uptake.

Ref: NCERT Class 12 Chemistry > Chapter 14: Biomolecules > Topic: Hormones - Protein Hormones and Regulation of Blood Glucose

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Hormones - Protein Hormones and Regulation of Blood Glucose

Which hormone is responsible for regulating blood glucose levels by decreasing it?

Insulin lowers blood glucose levels by facilitating glucose uptake into cells.

Ref: NCERT Class 12 Chemistry > Chapter 14: Biomolecules > Topic: Hormones - Protein Hormones and Regulation of Blood Glucose

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Hormones - Protein Hormones and Regulation of Blood Glucose

Which protein regulates blood sugar levels?

Insulin, a protein hormone, lowers blood glucose by promoting its uptake into cells.

Ref: NCERT Class 12 Chemistry > Chapter 14: Biomolecules > Topic: Hormones - Protein Hormones and Regulation of Blood Glucose

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Hormones - Protein Hormones and Regulation of Blood Glucose

Which hormone increases blood glucose levels?

Glucagon raises blood glucose levels by promoting glycogenolysis and gluconeogenesis in the liver.

Ref: NCERT Class 12 Chemistry > Chapter 14: Biomolecules > Topic: Hormones - Protein Hormones and Regulation of Blood Glucose

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VERNALIZATION & FLOWERING+PYQS

The effective temperature range for vernalization generally lies between:

Answer: B) 1–7°C. For VERNALIZATION & FLOWERING, remember the key idea and you’ll land on this option; the distractors usually swap cause and effect or confuse similar terms. Avoid: A) 10–25°C; C) 25–35°C; D) −10–0°C. Name the process first, then pick the option that describes it — don’t reverse cause and effect.

Ref: Best CSIR NET Plant Physiology books: Master Unit 6 with Taiz & Zeiger and Salisbury & Ross. Crack Part C experimental questions with top textbooks.

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VERNALIZATION & FLOWERING+PYQS

Vernalization is an active metabolic process and therefore does NOT occur in:

Correct option is D, Dry seeds. In VERNALIZATION & FLOWERING problems like this, the accurate statement is Dry seeds; the others are common mix-ups. Not these: A) Hydrated seeds; B) Young seedlings; C) Shoot apical meristem. Tissue transport questions usually turn on xylem vs phloem, living vs dead cells, or source vs sink.

Ref: Best CSIR NET Plant Physiology books: Master Unit 6 with Taiz & Zeiger and Salisbury & Ross. Crack Part C experimental questions with top textbooks.

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VERNALIZATION & FLOWERING+PYQS

Vernalization is best defined as:

That points to B: Acceleration of flowering by prolonged cold exposure. Compared with the other options, Acceleration of flowering by prolonged cold exposure is the one that correctly describes the VERNALIZATION & FLOWERING concept. The wrong ones are A) Promotion of flowering by long days; C) Inhibition of flowering by cold; D) Induction of dormancy by cold. If you’re stuck, eliminate anything that contradicts a basic fact you already know for this topic.

Ref: Best CSIR NET Plant Physiology books: Master Unit 6 with Taiz & Zeiger and Salisbury & Ross. Crack Part C experimental questions with top textbooks.

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