Free Biological Molecules MCQs with Answers
1,790 Biological Molecules MCQs from Biology, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
The chapter covers water's polarity and biological roles, carbohydrates, lipids, proteins and nucleic acids, including their monomers, bonds, structures and functions. It also distinguishes RNA from DNA and explains conjugated molecules such as glycoproteins, glycolipids and nucleoproteins, which combine organic molecules with a non-protein component.
Last updated
1,790 questions · page 10 of 90
- A. Polysaccharide
- B. Protein
- C. Hemoglobin
- D. ATP
Explanation: ATP is a relatively small molecule made from adenine, ribose, and three phosphate groups, and it transfers energy directly in cells.
Correct answer: ATP- A. 65%
- B. 18%
- C. 10%
- D. 3%
Explanation: Oxygen makes up about 65% of human body mass because most body oxygen is present in water, which forms a large fraction of the body, along…
Correct answer: 65%- A. 6
- B. 16
- C. 26
- D. 15
Explanation: Although many elements occur naturally, only about 16 are regarded as bio-elements because they are essential components of living matter…
Correct answer: 16184. On the basis of collected facts and figures, a scientist formulates a factitive statement called:
- A. Observation
- B. Research work
- C. Hypothesis
- D. Inductive Reasoning
Explanation: A hypothesis is a proposed, testable explanation or statement developed from observations and collected facts.
Correct answer: Hypothesis- A. Chloroplast
- B. A Nerve Cell
- C. DNA
- D. Hydrogen
Explanation: DNA is a very large molecule made of repeating nucleotide units, and each nucleotide contains a sugar, phosphate group, and nitrogenous…
Correct answer: DNA- A. Carbon
- B. Nitrogen
- C. Hydrogen
- D. Ammonia
Explanation: Carbon forms four covalent bonds and can make stable chains, rings, and complex structures, allowing it to serve as the backbone of…
Correct answer: Carbon- A. Kingdom Plantae
- B. Kingdom Protoctista
- C. Kingdom Monera
- D. Kingdom Animalia
Explanation: An earthworm is a multicellular, heterotrophic animal belonging to the phylum Annelida, so it is placed in Kingdom Animalia.
Correct answer: Kingdom Animalia- A. 126
- B. 86
- C. 92
- D. 206
Explanation: There are 92 naturally occurring chemical elements traditionally recognised in the periodic table, although only a smaller subset is…
Correct answer: 92- A. Basic
- B. Acidic
- C. Both
- D. None of these
Explanation: Nuclein was the original name given to the acidic nuclear material now understood to contain nucleic acid, whose phosphate groups give it…
Correct answer: Acidic- A. 8
- B. 4
- C. 6
- D. None of These
Explanation: Six elements, carbon, hydrogen, oxygen, nitrogen, phosphorus and sulphur, make up about 99% of the human body's mass and form the main…
Correct answer: 6- A. Vitamin-B
- B. Nicotine
- C. Morphine
- D. None of the above
Explanation: Fresh yeast is a useful source of B-complex vitamins, which act mainly as coenzymes in metabolic reactions.
Correct answer: Vitamin-B- A. Vitamin A
- B. Vitamin B
- C. Vitamin C
- D. Vitamin D
Explanation: Carrots contain beta-carotene, which the body converts into vitamin A, supporting vision and epithelial health.
Correct answer: Vitamin A- A. Plant Fibres
- B. Animal Fibres
- C. Natural Fibres
- D. Synthetic Fibres
Explanation: Cotton, wool and silk are all natural fibres because they are obtained from living organisms or their products rather than manufactured…
Correct answer: Natural Fibres- A. Albert Einstein
- B. Aristotle
- C. Ronald Fisher
- D. None of above
Explanation: Aristotle is traditionally called the father of biology because he made systematic observations and classifications of living organisms.
Correct answer: Aristotle- A. Life
- B. Community
- C. Cycle
- D. None of These
Explanation: The prefix bio comes from the Greek word bios, meaning life. Students may choose community because biology studies communities, but the…
Correct answer: Life- A. Sandfly , butterfly, hoeybee
- B. Sikmoth, honeybee, locust
- C. Honeybee, silkmoth, tsetse fly
- D. Honeybee , lac insect, cochineal insect
Explanation: Honeybees provide honey and wax, lac insects provide lac, and cochineal insects provide the red dye carmine, making this the set of useful…
Correct answer: Honeybee , lac insect, cochineal insect- A. Wasp
- B. Beetle
- C. Cricket
- D. Butterfly
Explanation: Moths and butterflies both belong to the order Lepidoptera and share scaled wings and a coiled proboscis in the adult stage.
Correct answer: Butterfly- A. Mite
- B. Spider
- C. Moth
- D. Scorpion
Explanation: A moth is an insect because it has six jointed legs, three body regions, and an exoskeleton, and it belongs to Lepidoptera.
Correct answer: Moth- A. Bedbug
- B. Mosquito
- C. Butterfly
- D. Cockroach
Explanation: Butterflies are generally diurnal, meaning they are active during daylight, whereas bedbugs, mosquitoes, and cockroaches are commonly…
Correct answer: Butterfly- A. Diatoms
- B. Euglenoids
- C. Dinoflagellates
- D. Brown algae
Explanation: Diatoms are major marine phytoplankton, so they carry out a very large share of photosynthesis and form the base of marine food chains.
Correct answer: Diatoms