Unit 3: Cell Structure and Function — Online MCQ Test
BIOLOGY · NEET (All) · NEET
Practice Unit 3: Cell Structure and Function with a free chapter-wise online MCQ test.
This chapter covers: Cell theory and cell as the basic unit of life; Structure of prokaryotic and eukaryotic cell; Plant cell and animal cell; Cell envelope cell membrane cell wall; Cell organelles-str....
AI-generated questions from basic to board-exam level, with instant results and explanations.
Unit 3: Cell Structure and Function — Important Questions & Answers
Identify the correct statement with regard to G1 phase (Gap 1) of interphase.
- A. Reorganisation of all cell components takes place.
- B. Cell is metabolically active, grows but does not replicate its DNA.
- C. Nuclear Division takes place.
- D. DNA synthesis or replication takes place.
Answer: B. Cell is metabolically active, grows but does not replicate its DNA.
In the G1 phase, the cell is metabolically active and continuously grows, but DNA replication does not occur (it occurs in the S phase).
In the G1 phase, the cell is metabolically active and continuously grows, but DNA replication does not occur (it occurs in the S phase).
Which of the following statements about inclusion bodies is incorrect?
- A. These are involved in ingestion of food particles.
- B. They lie free in the cytoplasm.
- C. These represent reserve material in cytoplasm.
- D. They are not bound by any membrane.
Answer: A. These are involved in ingestion of food particles.
Inclusion bodies in prokaryotes are non-membrane-bound structures used for storage of reserve materials; they are not involved in the ingestion of food particles.
Inclusion bodies in prokaryotes are non-membrane-bound structures used for storage of reserve materials; they are not involved in the ingestion of food particles.
Match the following with respect to meiosis: (a) Zygotene, (b) Pachytene, (c) Diplotene, (d) Diakinesis with (i) Terminalization, (ii) Chiasmata, (iii) Crossing over, (iv) Synapsis.
- A. 1) (iv) (iii) (ii) (i)
- B. 2) (i) (ii) (iv) (iii)
- C. 3) (ii) (iv) (iii) (i)
- D. 4) (iii) (iv) (i) (ii)
Answer: A. 1) (iv) (iii) (ii) (i)
Zygotene involves synapsis (a-iv). Pachytene involves crossing over (b-iii). Diplotene involves chiasmata (c-ii). Diakinesis involves terminalization of chiasmata (d-i).
Zygotene involves synapsis (a-iv). Pachytene involves crossing over (b-iii). Diplotene involves chiasmata (c-ii). Diakinesis involves terminalization of chiasmata (d-i).
Some dividing cells exit the cell cycle and enter vegetative inactive stage. This is called quiescent stage (G0). This process occurs at the end of:
- A. G1 phase
- B. S phase
- C. G2 phase
- D. M phase
Answer: A. G1 phase
Cells that do not divide further exit the G1 phase to enter an inactive stage called the quiescent stage (G0).
Cells that do not divide further exit the G1 phase to enter an inactive stage called the quiescent stage (G0).
Dissolution of the synaptonemal complex occurs during:
- A. Zygotene
- B. Diplotene
- C. Leptotene
- D. Pachytene
Answer: B. Diplotene
The dissolution of the synaptonemal complex marks the transition from pachytene to diplotene in prophase I of meiosis.
The dissolution of the synaptonemal complex marks the transition from pachytene to diplotene in prophase I of meiosis.
Which is the important site of formation of glycoproteins and glycolipids in eukaryotic cells?
- A. Peroxisomes
- B. Golgi bodies
- C. Polysomes
- D. Endoplasmic reticulum
Answer: B. Golgi bodies
The Golgi apparatus is the site of glycosylation where carbohydrates are added to proteins and lipids to form glycoproteins and glycolipids.
The Golgi apparatus is the site of glycosylation where carbohydrates are added to proteins and lipids to form glycoproteins and glycolipids.
The number of protons, neutrons and electrons in Lu, respectively, are:
- A. 104, 71 and 71
- B. 71, 71 and 104
- C. 175, 104 and 71
- D. 71, 104 and 71
Answer: D. 71, 104 and 71
For Lutetium (Lu), atomic number (Z) = 71 (protons = 71, electrons = 71). Mass number (A) = 175. Neutrons = A - Z = 175 - 71 = 104.
For Lutetium (Lu), atomic number (Z) = 71 (protons = 71, electrons = 71). Mass number (A) = 175. Neutrons = A - Z = 175 - 71 = 104.
From the statements given below choose the correct option: A. The eukaryotic ribosomes are 80S and prokaryotic ribosomes are 70S. B. Each ribosome has two sub-units. C. The two sub-units of 80S ribosome are 60S and 40S while that of 70S are 50S and 30S. D. The two sub-units of 80S ribosome are 60S and 20S and that of 70S are 50S and 20S. E. The two sub-units of 80S are 60S and 30S and that of 70S are 50S and 30S
- A. A, B, C are true
- B. A, B, D are true
- C. A, B, E are true
- D. B, D, E are true
Answer: A. A, B, C are true
Eukaryotic ribosomes (80S) consist of 60S and 40S subunits, while prokaryotic (70S) consist of 50S and 30S subunits. Thus A, B, and C are correct.
Eukaryotic ribosomes (80S) consist of 60S and 40S subunits, while prokaryotic (70S) consist of 50S and 30S subunits. Thus A, B, and C are correct.
A specialized membranous structure in a prokaryotic cell which helps in cell wall formation, DNA replication and respiration is:
- A. Mesosome
- B. Chromatophores
- C. Cristae
- D. Endoplasmic Reticulum
Answer: A. Mesosome
Mesosomes are characteristic infoldings of the plasma membrane in prokaryotes that perform functions analogous to mitochondria and the Golgi apparatus, including cell wall formation, DNA replication, and respiration.
Mesosomes are characteristic infoldings of the plasma membrane in prokaryotes that perform functions analogous to mitochondria and the Golgi apparatus, including cell wall formation, DNA replication, and respiration.
Which of the following events does not occur in rough endoplasmic reticulum?
- A. Protein glycosylation
- B. Cleavage of signal peptide
- C. Protein folding
- D. Phospholipid synthesis
Answer: D. Phospholipid synthesis
Phospholipid synthesis occurs primarily in the smooth endoplasmic reticulum (SER), not in the rough ER. Protein glycosylation (N-linked), cleavage of signal peptide, and protein folding (with help of chaperones) all occur in the RER lumen.
Phospholipid synthesis occurs primarily in the smooth endoplasmic reticulum (SER), not in the rough ER. Protein glycosylation (N-linked), cleavage of signal peptide, and protein folding (with help of chaperones) all occur in the RER lumen.