NEET Biology Previous Year Questions 2023 with Solutions

Question 51 of 100

🟢 NEET 2023 📘 CLASS XI 🌿 Animal Kingdom

Radial symmetry is NOT found in adults of phylum:

Explanation:

Radial symmetry in the adult stage is not seen in Hemichordata. They are bilaterally symmetrical as adults, with a tripartite body plan (proboscis, collar, trunk). In contrast, Echinodermata show radial symmetry as adults (pentaradial in many). Ctenophora are radially organized, usually with biradial features. Coelenterata (Cnidaria) show radial symmetry in adults (jellyfishes, corals). Hence, the correct option is 3, Hemichordata.

🧠 Did You Know?

Hemichordates are known for their collar-gill slits and protochordate features, linking them to vertebrates in evolutionary discussions.

💡 NCERT Memory Line:

Adults of Echinodermata and Cnidaria show radial symmetry; Hemichordata are bilaterally symmetrical as adults.

Question 52 of 100

🟢 NEET 2023 📘 CLASS XI 🌿 Animal Kingdom

Match List-I with List-II.

List-I	List-II
Taenia	Nephridia
Paramoecium	Contractile vacuole
Periplaneta	Flame cells
Pheretima	Urecose gland

Choose the correct answer from the options give below:

Explanation:

Correct option: 4. A-III

Question 53 of 100

🟢 NEET 2023 📘 CLASS XI 🌿 Structural Organisation In Animals

Given below are two statements:
Statement I: Ligaments are dense irregular tissue
Statement II: Cartilage is dense regular tissue.
In the light of above statements choose the correct answer from the option given below:

Explanation will be generated when opened.

Question 54 of 100

🟢 NEET 2023 📘 CLASS XI 🌿 Cell The Unit Of Life

Which of the following are NOT considered as the part of endomembrane system?
A. Mitochondria
B. Endoplasmic Reticulum
C. Chloroplasts
E. Peroxisomes
D.Golgi complex
Choose the most appropriate answer from the options given below:

Explanation:

The endomembrane system includes the nuclear envelope, endoplasmic reticulum, Golgi apparatus, lysosomes, vacuoles, and the plasma membrane. Mitochondria, chloroplasts, and peroxisomes are not part of this system. Therefore, the correct choice is 3: A, C and E only (mitochondria, chloroplasts, and peroxisomes are not part of endomembrane). Options that include ER or Golgi (B and D) or mix in these with non-endomembrane organelles are not correct.

🧠 Did You Know?

In NCERT, mitochondria and chloroplasts have their own DNA and ribosomes and are not components of the endomembrane system.

💡 NCERT Memory Line:

Endomembrane system: nuclear envelope, ER, Golgi, lysosomes, vacuoles, and plasma membrane.

Question 55 of 100

🟢 NEET 2023 📘 CLASS XI 🌿 Cell The Unit Of Life

Which of the following functions is carried out by cytoskeleton in a cell?

Explanation:

The cytoskeleton provides mechanical support and enables movement of the cell and its parts. It helps in motility, such as movement of the cell itself (e.g., in certain cells with flagella or cilia) and in the movement/positioning of organelles. Among the options, motility is the primary function highlighted by NCERT as a role of the cytoskeleton. Protein synthesis is carried out by ribosomes; nuclear division involves spindle apparatus but is not the main named function of the cytoskeleton in this context; transportation of materials occurs along cytoskeletal elements, but the option that best captures the core idea is motility.

🧠 Did You Know?

Microtubules and actin filaments form tracks along which organelles and vesicles are moved inside the cell.

💡 NCERT Memory Line:

Cytoskeleton helps in movement and support of the cell, aiding motility and organelle transport.

Question 56 of 100

🟢 NEET 2023 📘 CLASS XI 🌿 Biomolecules

Given below are two statements:
Statement I: Low temperature preserves the enzyme in a temporarily inactive state whereas high temperature destroys enzymatic activity because proteins are denatured by heat. Statement II: When the inhibitor closely resembles the substrate in its molecular structure and inhibits the activity of the enzyme, it is known as competitive inhibitor.
In the light of the above statements, choose the correct answer from the options given below:

Explanation will be generated when opened.

Question 57 of 100

🟢 NEET 2023 📘 CLASS XI 🌿 Biomolecules

Given below are two statements:
Statement I: A protein is imagined as a line, the left end represented by first amino acid (C-terminal) and the right end represented by last amino acid (N-terminal)
Statement II: Adult human haemoglobin, consists of 4 subunits (two subunits of α type and two subunits of β type.)
In the light of the above statements, choose the correct answer from the options given below:

Explanation will be generated when opened.

Question 58 of 100

🟢 NEET 2023 📘 CLASS XI 🌿 Digestion And Absorption

Match List-I with List-II.

List-I (Cells)	List-II (Secretion)
(A)Peptic cells	(I)Mucus
(B)Goblet Cells	(II)Bile Juice
(C)Oxyntic Cell	(III)Proenzyme Pepsinogen
(D)Hepatic cells	(IV)HCl and intrinsic factor for absorption of vitamin B₁₂

Choose the correct answer from the options given below:

Explanation will be generated when opened.

Question 59 of 100

🟢 NEET 2023 📘 CLASS XI 🌿 Digestion And Absorption

Once the undigested and unabsorbed substances enter the caecum, their backflow is prevented by:

Explanation will be generated when opened.

Question 60 of 100

🟢 NEET 2023 📘 CLASS XI 🌿 Breathing And Exchange Of Gases

Vital capacity of lung is ________.

Explanation will be generated when opened.

NEET Biology 2023 PYQs