CDS Biology Questions

Answer with full explanation — CDS 2025 (I) →

CDS 2025 Session I Respiration & Metabolismeasy

Q79. How many Carbon atoms are present in a Pyruvate molecule?

(a)2

(b)3

(d)5

Q44. Which one of the following is the correct combination of organelles and their functions?

(a)Mitochondria – Respiration; Chloroplast – Photosynthesis; Ribosome – Protein Synthesis; Rough endoplasmic reticulum – Transport of proteins

(b)Mitochondria – Respiration; Chloroplast – Photosynthesis; Ribosome – Transport of proteins; Rough endoplasmic reticulum – Protein synthesis

(c)Mitochondria – Respiration; Chloroplast – Protein synthesis; Ribosome – Photosynthesis; Rough endoplasmic reticulum – Transport of proteins

(d)Mitochondria – Photosynthesis; Chloroplast – Respiration; Ribosome – Protein synthesis; Rough endoplasmic reticulum – Transport of proteins

Q45. Cell wall is absent in which one of the following organisms?

(a)Bacteria

(b)Diatom

(c)Mushroom

(d)Tapeworm

CDS 2023 Session II Plant Physiology

Q46. Water goes up through xylem vessels in tall trees. The process in plants and properties of water that help in upward movement are:

(a)Respiration and cohesion

(b)Transpiration pull, cohesion and adhesion

(c)Root pressure, cohesion and adhesion

(d)Transpiration and adhesion

CDS 2023 Session II Ecology

Q47. Energy and nutrients flow from one trophic level to another in an ecosystem. Which one of the following statements correctly describes the direction of flow of energy and nutrients in an ecosystem?

(a)Energy flow is cyclic and nutrient flow is unidirectional.

(b)Energy flow is unidirectional and nutrient flow is cyclic.

(c)Both energy and nutrient flow are unidirectional.

(d)Both energy and nutrient flow are cyclic.

CDS 2023 Session II Plant Kingdom

Q48. Which one of the following is a saprophyte?

(a)Cuscuta

(b)Rhizopus

(c)Spirogyra

(d)Grass

Indian Economy (328)Science & Technology (276)General Studies (160)Indian Polity (147)Geography (125)Modern History (63)Defence & Security (57)Current Affairs (40)Environment & Ecology (38)Art & Culture (33)History (29)General Science (27)Ancient History (26)International Relations (19)Medieval History (18)Chemistry (17)Geology & Geophysics (9)Internal Security (7)

Other CDS Subjects

Explore More UPSC Other Exam PYQs

NDA PYQ

National Defence Academy

CAPF PYQ

Central Armed Police Forces

CDS vs NDA CDS vs CAPF

All UPSC Other Exams →UPSC Prelims PYQ →State PCS PYQ →

CDS Biology Questions

7 previous year questions

Sub-topics

Cell Biology (2)Human Physiology (1)Respiration & Metabolism (1)Plant Physiology (1)Ecology (1)Plant Kingdom (1)

CDS 2025 Session II Human Physiologyeasy

Q45. Which of the following are the different parts of a human brain?

(a)Forefront brain, Standard brain and Hind brain

(b)Fore brain, Median brain and Rear brain

(c)Fore brain, Mid brain and Hind brain

(d)Precursor brain, Mean brain and Hind brain

Answer with full explanation — CDS 2025 (II) →

Answer with full explanation — CDS 2025 (I) →

CDS 2025 Session I Respiration & Metabolismeasy

Q79. How many Carbon atoms are present in a Pyruvate molecule?

(a)2

(b)3

(d)5

Q44. Which one of the following is the correct combination of organelles and their functions?

(a)Mitochondria – Respiration; Chloroplast – Photosynthesis; Ribosome – Protein Synthesis; Rough endoplasmic reticulum – Transport of proteins

(b)Mitochondria – Respiration; Chloroplast – Photosynthesis; Ribosome – Transport of proteins; Rough endoplasmic reticulum – Protein synthesis

(c)Mitochondria – Respiration; Chloroplast – Protein synthesis; Ribosome – Photosynthesis; Rough endoplasmic reticulum – Transport of proteins

(d)Mitochondria – Photosynthesis; Chloroplast – Respiration; Ribosome – Protein synthesis; Rough endoplasmic reticulum – Transport of proteins

Q45. Cell wall is absent in which one of the following organisms?

(a)Bacteria

(b)Diatom

(c)Mushroom

(d)Tapeworm

CDS 2023 Session II Plant Physiology

Q46. Water goes up through xylem vessels in tall trees. The process in plants and properties of water that help in upward movement are:

(a)Respiration and cohesion

(b)Transpiration pull, cohesion and adhesion

(c)Root pressure, cohesion and adhesion

(d)Transpiration and adhesion

CDS 2023 Session II Ecology

(a)Energy flow is cyclic and nutrient flow is unidirectional.

(b)Energy flow is unidirectional and nutrient flow is cyclic.

(c)Both energy and nutrient flow are unidirectional.

(d)Both energy and nutrient flow are cyclic.

CDS 2023 Session II Plant Kingdom

Q48. Which one of the following is a saprophyte?

(a)Cuscuta

(b)Rhizopus

(c)Spirogyra

(d)Grass