All Free Biology MCQs with Answers
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19844 questions · page 611 of 1985
6101. Which of the following structure is involved in oxidative phosphorylation?
- A. Inner mitochondrial membrane
- B. Mitochondrial matrix
- C. Outer mitochondrial membrane
- D. Thylakoid membrane
Explanation: ETC occurs in inner mitochondrial membrane which provides the site for pumping of protons across it. Oxidative phosphorylation is associated with ETC.
Correct answer: Inner mitochondrial membrane6102. Krebs cycle occurs in_ of mitochondria.
- A. Matrix
- B. F1 Particles
- C. Stroma
- D. Cristae
Explanation: All the enzymes which are involved in krebs cycle are present in matrix of mitochondria. It is the most important biochemical pathway of cellular respiration. The enzymes involved in dark reactions of photosynthesis are found in stroma of chloroplasts.
Correct answer: Matrix6103. Which of the following cell type is more appropriate to study mitochondria?
- A. RBC
- B. Muscle cell
- C. Mesophyll cell
- D. E.coli
Explanation: Mitochondria are most abundant in muscle cells because of the strenuous metabolic activities, E.coli is a prokaryotic organism and lack mitochondria. RBC's also lack mitochondria.
Correct answer: Muscle cell6104. Which of the following eukaryotic organelle has symbiotic origin with bacteria?
- A. Endoplasmic reticulum
- B. Chloroplast
- C. Lysosomes
- D. Golgi apparatus
Explanation: Two most important organelles. e.g chloroplast and mitochondria, are thought to be originated from prokaryotes and are explain with the help of endosymbiont hypothesis.
Correct answer: Chloroplast6105. Chlorophyll molecule resembles with:
- A. Carotenoids
- B. Xanthophylls
- C. Globin chains of hemoglobin
- D. Haem part of hemoglobin
Explanation: The only difference between chlorophyll and haemoglobin is that chlorophyll has Mg+4 while haem has Fe+2 as the central atom.
Correct answer: Globin chains of hemoglobin6106. Which of the following statements is incorrect?
- A. CO2 fixation occurs in stroma
- B. Inter-granum is photosynthetic
- C. Chloroplasts are self-replicating
- D. Chloroplasts have 70S ribosomes
Explanation: Photosynthetic pigments are present on grana of thyllakoid, so they are site of photosynthesis. Intergranum does not contain any photosynthetic pigment, so they cannot be the site of photosynthesis.
Correct answer: Inter-granum is photosynthetic6107. Nucleolus is visible in:
- A. Interphase
- B. Mitotic phase
- C. Metaphase
- D. Anaphase
Explanation: Nucleus and nucleolus is visible during interphase only because in mitotic phase, nuclear envelope disintegrates and mixing of nuclear contents with cytoplasm does occur.
Correct answer: Interphase6108. Which option precisely describes the function of nucleoli?
- A. Formation and breakdown of nuclear envelope.
- B. Formation of centromere
- C. Formation of ribosomes
- D. Organization of spindle during nuclear division
Explanation: Nucleolus is the darkly stained area within the nucleus and without any membranous boundary to separate it from the rest of the nuclear material. These are said to be the factory of ribosomes while ribosomes are said to be the factory of protein synthesis.
Correct answer: Formation of ribosomes6109. Prokaryotic and eukaryotic cells generally have which of the following features in common?
- A. A membrane bounded nucleus
- B. Presence of ribosomes
- C. A cell wall made up of cellulose
- D. Linear genome
Explanation: Both prokaryotic and eukaryotic cells have ribosomes while membrane bound nucleus, cellulosic cell wall and linear chromosomes are found only in eukaryotic cells.
Correct answer: Presence of ribosomes6110. Which one of the following is most slender in structure?
- A. Microtubules
- B. Microfilaments
- C. Intermediate filaments
- D. Both A and B
Explanation: Microfilaments are considerably more slender cylinders made up of contractile actin protein, linked to the inner face of plasma membrane.
Correct answer: Microfilaments