Cellular Organisation, Biomolecules, and Cell Division: MCQ Test

21. Which of the following is true regarding the cell wall of a young plant cell?

• It is mainly composed of calcium pectate.
• It is called the secondary wall and is formed on the outer side.
• It is the primary wall and is capable of growth.
• It contains plasmodesmata that connect cytoplasm of neighbouring cells, but is not capable of growth.

22. The middle lamella, which holds or glues different neighboring cells together, is mainly composed of:

• Cellulose
• Hemicellulose
• Pectins
• Calcium pectate

23. The endomembrane system includes a coordinated group of organelles. Which of the following are NOT considered part of the endomembrane system due to their functions not being coordinated with the others?

• Endoplasmic Reticulum and Golgi complex
• Lysosomes and Vacuoles
• Mitochondria and Chloroplasts
• ER, Golgi, Lysosomes, and Vacuoles

24. Where are steroidal hormones synthesized in animal cells?

• Rough Endoplasmic Reticulum (RER)
• Smooth Endoplasmic Reticulum (SER)
• Golgi apparatus
• Lysosomes

25. Which organelle is the important site of formation of glycoproteins and glycolipids?

• Endoplasmic Reticulum
• Mitochondria
• Golgi apparatus
• Ribosomes

26. Lysosomes are membrane-bound vesicular structures rich in hydrolytic enzymes. At what pH are these enzymes optimally active?

• Neutral pH
• Alkaline pH
• Acidic pH
• Any pH as long as substrate is present

27. In plant cells, the tonoplast, a single membrane, facilitates the transport of ions and other materials into the vacuole against concentration gradients. What does this imply about the concentration of materials inside the vacuole compared to the cytoplasm?

• Significantly lower in the vacuole
• Significantly higher in the vacuole
• Equal in the vacuole and cytoplasm
• Only water is transported, not ions

28. Mitochondria are often called the 'power houses' of the cell because they produce cellular energy in the form of ATP. What is the approximate average diameter of a typical mitochondrion?

• 0.1 µm
• 0.5 µm
• 1.0 µm
• 2.0 µm

29. The inner membrane of the mitochondrion forms a number of infoldings towards the matrix. What are these infoldings called, and what is their primary purpose?

• Thylakoids; to store pigments
• Cisternae; to package materials
• Cristae; to increase surface area
• Mesosomes; for DNA replication

30. Besides the nucleus, which two organelles in eukaryotic cells are known to contain their own 70S ribosomes and a single circular DNA molecule?

• Endoplasmic Reticulum and Golgi apparatus
• Lysosomes and Vacuoles
• Mitochondria and Chloroplasts
• Peroxisomes and Microbodies

31. Plastids are classified based on the type of pigments they bear. Which type of plastids are colourless and are primarily involved in storing nutrients like carbohydrates (starch), oils/fats, or proteins?

• Chloroplasts
• Chromoplasts
• Leucoplasts
• Elaioplasts (a type of leucoplast)

32. In chloroplasts, the organised flattened membranous sacs present in the stroma are called thylakoids. When these thylakoids are arranged in stacks, what are these stacks called?

• Cristae
• Cisternae
• Grana
• Lumen

33. In chloroplasts, what are the flat membranous tubules that connect the thylakoids of different grana?

• Outer membrane
• Stroma lamellae
• Inner membrane
• Lumen

34. The ribosomes of chloroplasts and mitochondria are __________S, while the cytoplasmic ribosomes of eukaryotic cells are __________S.

• 80; 70
• 70; 80
• 60; 40
• 50; 30

35. What is the characteristic arrangement of microtubules in the axoneme of cilia and flagella?

• 8+1 array
• 9+0 array
• 9+2 array
• 10+2 array

36. The centrosome, typically containing two cylindrical centrioles, is surrounded by amorphous pericentriolar materials. What is the organization of each centriole described as, and what protein are its peripheral fibrils made of?

• Spiral; actin
• Cartwheel; tubulin
• Fibrous; collagen
• Hexagonal; keratin

37. Robert Brown first described the nucleus in 1831. Later, what name was given to the material of the nucleus that stained by basic dyes by Flemming?

• Nucleolus
• Nucleoplasm
• Chromatin
• Karyoplasm

38. The nuclear envelope consists of two parallel membranes with a space between them. What is this space called, and what is its approximate width?

• Cytosolic space; 5-10 nm
• Perinuclear space; 10-50 nm
• Intranuclear lumen; 50-100 nm
• Intermembrane space; 1-5 nm

39. Which of the following mature cells in mammals and vascular plants typically lack a nucleus?

• Nerve cells and root hair cells
• Muscle cells and epidermal cells
• Erythrocytes and sieve tube cells
• Mesophyll cells and guard cells

40. The nucleolus is a spherical structure present in the nucleoplasm. Which of the following is true about its nature and function?

• It is a membrane-bound organelle involved in lipid synthesis.
• It is a non-membrane bound structure, continuous with nucleoplasm, and is a site for active ribosomal RNA synthesis.
• It contains chromosomes and controls cell activities.
• It is involved in DNA replication and protein packaging.