Life Processes in Animals Part 1: MCQs (Q1–Q25)

Part 1 — Nutrition & Feeding in Animals (Questions 1–25)

1. Animals that obtain food by eating plants are called:

A. Carnivores
B. Herbivores
C. Omnivores
D. Parasites
Correct answer: B. Herbivores

Explanations:
A) Carnivores eat animals — incorrect.
B) Herbivores eat plants — correct.
C) Omnivores eat both plants and animals — incorrect.
D) Parasites live on/in host and take nutrition often harming host — incorrect.

2. The type of nutrition in which organisms make their own food using sunlight is called:

A. Heterotrophic nutrition
B. Saprophytic nutrition
C. Autotrophic nutrition
D. Parasitic nutrition
Correct answer: C. Autotrophic nutrition

Explanations:
A) Heterotrophs obtain ready-made food — incorrect.
B) Saprophytes feed on dead matter — incorrect.
C) Autotrophs (like plants) synthesize food using sunlight — correct.
D) Parasitic nutrition involves living host — incorrect.

3. Animals that eat both plants and animals are called:

A. Herbivores
B. Omnivores
C. Carnivores
D. Scavengers
Correct answer: B. Omnivores

Explanations:
A) Herbivores eat only plants — incorrect.
B) Omnivores eat both plant and animal matter — correct.
C) Carnivores eat mainly animals — incorrect.
D) Scavengers eat dead organisms — not necessarily both live plants & animals — incorrect.

4. A cow’s stomach has several chambers and microbes to digest cellulose. This is an adaptation for feeding on:

A. Flesh
B. Grass (cellulose-rich food)
C. Seeds only
D. Dead animals
Correct answer: B. Grass (cellulose-rich food)

Explanations:
A) Flesh does not require multi-chambered stomachs — incorrect.
B) Ruminant stomachs help digest cellulose in grass — correct.
C) Seeds don’t need such complex fermentation — incorrect.
D) Dead animals — not typical for ruminants — incorrect.

5. Which of the following is an example of saprophytic nutrition?

A. Human digestion
B. Mushroom growing on fallen log
C. Tapeworm in intestine
D. Cow chewing cud
Correct answer: B. Mushroom growing on fallen log

Explanations:
A) Human digestion is heterotrophic but not saprophytic — incorrect.
B) Mushrooms secrete enzymes and absorb nutrients from dead matter — correct.
C) Tapeworm is parasitic (feeds on host) — incorrect.
D) Cow rumination is herbivory + microbial fermentation — incorrect.

6. A parasite is an organism that:

A. Lives independently and makes its own food
B. Lives on/in another organism and obtains nutrition from it
C. Feeds on dead and decaying matter
D. Eats only plants
Correct answer: B. Lives on/in another organism and obtains nutrition from it

Explanations:
A) That describes autotrophs or free-living organisms — incorrect.
B) Parasitic organisms derive nutrients from a host — correct.
C) Feeding on dead matter is saprophytic — incorrect.
D) Eats only plants = herbivore — incorrect.

7. The physical breakdown of food into smaller pieces occurs mainly in the:

A. Stomach (chemical only)
B. Mouth (chewing)
C. Small intestine only
D. Large intestine only
Correct answer: B. Mouth (chewing)

Explanations:
A) Stomach does mechanical stirring and chemical digestion; but initial physical breakdown is in mouth — partially true but not main — incorrect.
B) Teeth chew food — correct.
C) Small intestine mainly chemical digestion and absorption — incorrect.
D) Large intestine absorbs water; little breakdown — incorrect.

8. Peristalsis is the:

A. Chemical digestion by enzymes
B. Wave-like muscular movement that pushes food along the alimentary canal
C. Absorption of nutrients in the intestine
D. Release of bile from gall bladder
Correct answer: B. Wave-like muscular movement that pushes food along the alimentary canal

Explanations:
A) Chemical digestion is enzyme action — incorrect.
B) Peristalsis is coordinated muscular contractions — correct.
C) Absorption is a different process — incorrect.
D) Bile release is secretion — incorrect.

9. Which of the following secretes saliva that contains the enzyme salivary amylase?

A. Pancreas
B. Liver
C. Salivary glands
D. Stomach lining
Correct answer: C. Salivary glands

Explanations:
A) Pancreas secretes pancreatic juice — incorrect.
B) Liver produces bile, not saliva — incorrect.
C) Salivary glands secrete saliva with salivary amylase — correct.
D) Stomach lining secretes gastric juice (HCl, pepsinogen) — incorrect.

10. Teeth that are sharp and pointed and used to tear flesh are called:

A. Incisors
B. Molars
C. Canines
D. Premolars
Correct answer: C. Canines

Explanations:
A) Incisors cut food — incorrect.
B) Molars grind food — incorrect.
C) Canines tear food (flesh) — correct.
D) Premolars help in crushing and tearing but not primarily tearing — incorrect.

11. Which animal has a crop and gizzard for food storage and grinding?

A. Cow
B. Earthworm
C. Bird
D. Fish
Correct answer: C. Bird

Explanations:
A) Cow has multi-chambered stomach — incorrect.
B) Earthworm has crop and gizzard — actually earthworms have crop & gizzard too; but for board-level the expected answer is C (bird) — careful: earthworms also have crop & gizzard. (If appearing in exam this question must specify ‘commonly seen in birds and earthworms’ — but typical board q expects birds.)
C) Birds have crop (store) and gizzard (grind) — correct for birds.
D) Fish lack crop and gizzard — incorrect.

(Note: earthworms also have crop & gizzard — exam phrasing can vary. The above is for bird-focused question.)

12. The enzyme pepsin works in the:

A. Mouth
B. Stomach
C. Small intestine
D. Large intestine
Correct answer: B. Stomach

Explanations:
A) Mouth has salivary amylase, not pepsin — incorrect.
B) Pepsin (active form of pepsinogen) digests proteins in stomach — correct.
C) Small intestine has trypsin, peptidases, not pepsin — incorrect.
D) Large intestine mainly absorbs water — incorrect.

13. Bile helps in digestion by:

A. Chemically breaking proteins into amino acids
B. Emulsifying fats (breaking large fat droplets into small droplets)
C. Digestion of carbohydrates
D. Killing bacteria only
Correct answer: B. Emulsifying fats (breaking large fat droplets into small droplets)

Explanations:
A) Proteins are not digested by bile — incorrect.
B) Bile emulsifies fats, increasing surface area for lipase — correct.
C) Carbohydrate digestion is by salivary/pancreatic amylase — incorrect.
D) Bile may help in detox but main role is emulsification — incorrect.

14. Which organ produces bile?

A. Pancreas
B. Liver
C. Stomach
D. Gall bladder
Correct answer: B. Liver

Explanations:
A) Pancreas produces pancreatic juice — incorrect.
B) Liver produces bile — correct.
C) Stomach produces gastric juice — incorrect.
D) Gall bladder stores (concentrates) bile; it does not produce it — incorrect.

15. In humans, the major site of absorption of digested food is:

A. Stomach
B. Small intestine (especially ileum)
C. Large intestine
D. Mouth
Correct answer: B. Small intestine (especially ileum)

Explanations:
A) Stomach digests but absorbs few substances like alcohol — incorrect.
B) Small intestine (with villi) absorbs nutrients — correct.
C) Large intestine absorbs water and some minerals — incorrect.
D) Mouth does not absorb nutrients — incorrect.

16. Which structure increases the surface area for absorption in the small intestine?

A. Teeth
B. Alveoli
C. Villi
D. Cilia
Correct answer: C. Villi

Explanations:
A) Teeth are for chewing — incorrect.
B) Alveoli are in lungs for gas exchange — incorrect.
C) Villi (finger-like projections) increase surface area of intestine — correct.
D) Cilia are hair-like structures in respiratory tract — incorrect.

17. The opening through which undigested food is expelled is called:

A. Anus
B. Mouth
C. Pancreas
D. Stomach
Correct answer: A. Anus

Explanations:
A) Anus is the exit for undigested food (faeces) — correct.
B) Mouth is entry — incorrect.
C) Pancreas secretes enzymes — incorrect.
D) Stomach stores and digests; not exit — incorrect.

18. Saliva helps digestion by:

A. Killing all bacteria only
B. Providing enzyme (salivary amylase) to begin carbohydrate digestion and moistening food
C. Emulsifying fats
D. Neutralizing stomach acid
Correct answer: B. Providing enzyme (salivary amylase) to begin carbohydrate digestion and moistening food

Explanations:
A) Saliva has some antibacterial components but main role is not only killing bacteria — incorrect.
B) Saliva moistens food and contains salivary amylase to start starch digestion — correct.
C) Emulsification is bile’s role — incorrect.
D) Neutralizing stomach acid is not a function of saliva — incorrect.

19. The rodent-like animal continuously gnaws and has incisors adapted for gnawing. These are examples of _____ adaptation for nutrition.

A. Structural adaptation
B. Behavioral adaptation
C. Physiological adaptation
D. Cellular adaptation
Correct answer: A. Structural adaptation

Explanations:
A) Teeth shape is a body structure adaptation — correct.
B) Behavioral adaptation would be what animal does, not tooth shape — incorrect.
C) Physiological adaptation refers to internal chemical processes — incorrect.
D) Cellular adaptation is not applicable here — incorrect.

20. Which organ stores and concentrates bile?

A. Liver
B. Gall bladder
C. Pancreas
D. Stomach
Correct answer: B. Gall bladder

Explanations:
A) Liver produces bile — incorrect (doesn’t store it).
B) Gall bladder stores and concentrates bile — correct.
C) Pancreas secretes pancreatic juice — incorrect.
D) Stomach stores food — incorrect.

21. Which of the following is true about ruminants (like cows)?

A. They have a single-chambered stomach like humans
B. They swallow food whole and digest in gizzard
C. They regurgitate and re-chew food (cud) to help digestion
D. They digest only proteins and fats
Correct answer: C. They regurgitate and re-chew food (cud) to help digestion

Explanations:
A) Ruminants have a multi-chambered stomach — incorrect.
B) Gizzard is in birds/earthworms, not ruminants — incorrect.
C) Cud chewing (rumination) helps break cellulose — correct.
D) They digest carbohydrates in cellulose with microbes — incorrect.

22. A snail uses a rasping tongue-like organ called radula to scrape food. This is an example of:

A. Digestive enzyme activity
B. Mechanical adaptation for feeding
C. Respiration
D. Excretion
Correct answer: B. Mechanical adaptation for feeding

Explanations:
A) Enzymes are chemical; radula is physical — incorrect.
B) Radula mechanically scrapes food — correct.
C) Not related to respiration — incorrect.
D) Not related to excretion — incorrect.

23. Which of the following groups use a filter-feeding method to obtain food?

A. Herbivores like cow
B. Baleen whales and some aquatic invertebrates
C. Tapeworms (internal parasites)
D. Insectivorous plants
Correct answer: B. Baleen whales and some aquatic invertebrates

Explanations:
A) Cows graze, not filter-feed — incorrect.
B) Baleen whales filter plankton; aquatic invertebrates like sponges filter — correct.
C) Tapeworms absorb nutrients from host, not filter-feed — incorrect.
D) Insectivorous plants trap insects, not filter aquatic particles — incorrect.

24. The first step in human digestion is:

A. Absorption in intestine
B. Chewing and mixing with saliva in mouth
C. Protein digestion in stomach
D. Emulsification of fats in small intestine
Correct answer: B. Chewing and mixing with saliva in mouth

Explanations:
A) Absorption comes after digestion — incorrect.
B) Mechanical and chemical digestion begins in mouth — correct.
C) Protein digestion begins in stomach, but not first — incorrect.
D) Emulsification happens later — incorrect.

25. Which of the following statements is correct?

A. All animals breathe through lungs.
B. Respiration is same as breathing.
C. Cellular respiration releases energy by oxidizing food molecules.
D. Aquatic animals do not need respiration.
Correct answer: C. Cellular respiration releases energy by oxidizing food molecules.

Explanations:
A) Not true — some animals use gills, skin, tracheae — incorrect.
B) Breathing (ventilation) is physical; respiration is biochemical — incorrect.
C) Cellular respiration produces energy by oxidation — correct.
D) All living animals need respiration to get energy — incorrect. (more…)