Cell Structure and Function
- Which is the important site of formation of glycoproteins and glycolipids in eukaryotic cells ? Answer: 3. Golgi bodies Key idea: Golgi bodies modify and package products from the ER. Proteins and lipids from the ER reach the Golgi, whe... 1
- The concept of "Omnis cellula-e cellula" regarding cell division was first proposed by : Answer: 1. Rudolf Virchow Key idea: Rudolf Virchow proposed "Omnis cellula-e cellula" (new cells come from pre-existing cells) in 1855. Schl... 1
- Cells in G_0 phase : Answer: 3. suspend the cell cycle Cells that do not divide further leave the active cycle at G₁ and enter the quiescent G₀ stage. They remai... 1
- Which of the following statements regarding mitochondria is incorrect ? Answer: 2. Enzymes of electron transport are embedded in outer membrane. The enzymes of the electron transport chain are in the inner mitoch... 1
- Concanavalin A is : Answer: 3. a lectin Concanavalin A is a lectin, a carbohydrate-binding protein extracted from jack bean. It is not an alkaloid, an essential... 1
- The correct sequence of phases of cell cycle is : Answer: 4. G ₁ → S → G ₂ → M The cell cycle runs G₁ → S → G₂ → M . G₁ is growth, S is DNA synthesis, G₂ is preparation for division, and M i... 1
- The shorter and longer arms of a submetacentric chromosome are referred to as : Answer: 2. p-arm and q-arm respectively By convention the shorter arm of a chromosome is the p-arm (petite) and the longer arm is the q-arm.... 1
- Which of the following statements is not correct ? Answer: 4. Lysosomes are formed by the process of packaging in the endoplasmic reticulum. Lysosomes are membrane-bound vesicles holding hydr... 1
- Consider the following statements :(A) Coenzyme or metal ion that is tightly bound to enzyme protein is called prosthetic group.(B) A complete catalytic active enzyme with its bound prosthetic group is called apoenzyme.Select the correct option. Answer: 2. (A) is true but (B) is false. Statement A is true. A cofactor (organic or metal ion) that is tightly bound to the enzyme protein... 1
- Which of the following pair of organelles does not contain DNA ? Answer: 3. Lysosomes and Vacuoles Mitochondria and chloroplasts contain their own DNA, and the nucleus holds the cell's DNA. Lysosomes and v... 1
- Select the incorrect match : Answer: 4. Polytene Chromosomes – Oocytes of amphibians Key idea: Check each pair. Lampbrush chromosomes are diplotene bivalents (in amphibi... 1
- Which of the following events does not occur in rough endoplasmic reticulum ? Answer: 4. Phospholipid synthesis Key idea: The rough ER has ribosomes and handles proteins that enter its lumen. Protein folding, cleavage... 1
- The two functional groups characteristic of sugars are Answer: 4. carbonyl and hydroxyl Sugars are polyhydroxy aldehydes or ketones, so they have a carbonyl group (aldehyde or ketone) and several... 1
- The stage during which separation of the paired homologous chromosomes begins is Answer: 3. Diplotene In prophase I, homologous chromosomes start to separate at diplotene, held together at chiasmata. Zygotene is pairing (... 1
- Which of the following is true for nucleolus ? Answer: 4. It is a site for active ribosomal RNA synthesis. The nucleolus is a non-membranous site of active rRNA synthesis and ribosome ass... 1
- The Golgi complex participates in Answer: 3. Formation of secretory vesicles The Golgi complex packs and sorts proteins and lipids into vesicles, including secretory vesicles... 1
- Which of the following options gives the correct sequence of events during mitosis ? Answer: 1. condensation → nuclear membrane disassembly → arrangement at equator → centromere division → segregation → telophase The correct... 1
- Which of the following components provides sticky character to the bacterial cell ? Answer: 3. Glycocalyx The glycocalyx is the outer layer of the bacterial cell envelope, made of polysaccharide (and sometimes protein). It i... 1
- Anaphase Promoting Complex (APC) is a protein degradation machinery necessary for proper mitosis of animal cells. If APC is defective in a human cell, which of the following is expected to occur ? Answer: 2. Chromosomes will not segregate Key idea: APC degrades securin so that separase can cut cohesin between sister chromatids at the m... 1
- Which of the following cell organelles is responsible for extracting energy from carbohydrates to form ATP ? Answer: 3. Mitochondrion Key idea: ATP is made from the breakdown of food by cellular respiration. The mitochondrion oxidises pyruvate from... 1
- Which one of the following statements is correct, with reference to enzymes ? Answer: 1. Holoenzyme = Apoenzyme + Coenzyme Key idea: An active conjugated enzyme has a protein part and a non-protein part. The protein pa... 1
- Which of the following is the least likely to be involved in stabilizing the three-dimensional folding of most proteins? Answer: 3. Ester bonds Protein 3D structure is stabilised by hydrogen bonds, hydrophobic interactions, ionic (electrostatic) interactions an... 1
- When cell has stalled DNA replication fork, which checkpoint should be predominantly activated? Answer: 1. G ₂ /M A stalled replication fork means DNA is not fully replicated. The cell must delay entry into mitosis until replication and... 1
- Which of the following describes the given graph correctly? Answer: 1. Exothermic reaction with energy A in presence of enzyme and B in absence of enzyme The graph shows energy released, and the arrow... 1