All Free Biology MCQs with Answers

• A. Phospholipids
• B. Cellulose
• C. Cholesterol
• D. Vitamin A

Explanation: Cellulose has no double bonds. Cholesterol and Retinol (vitamin A) have double bonds.

• A. Some hormones
• B. Enzymes
• C. Skin terdons
• D. insulin

Explanation: Steroid hormones are derived from lipids. They include testosterone, estrogen, and cortisol, among others.

• A. Acids
• B. Alcohols
• C. Ethers
• D. Esters

Explanation: Lipids are chemically classified as esters because they are formed through a reaction between fatty acids and an alcohol (typically…

• A. Proteins
• B. Amino acids
• C. Carbohydrates
• D. Esters

Explanation: Lipids are predominantly made up of fatty acids and glycerol. The ester bond formed between these components categorizes lipids as esters.

• A. Always results in the formation of soaps.
• B. Results in the formation of esters.
• C. Results in the formation of waxes.
• D. Results in the formation of glycerol and soap.

Explanation: Saponification is a chemical process where fats or oils react with an alkali, such as sodium hydroxide (NaOH) or potassium hydroxide…

• A. Monohydroxy alcohols
• B. Dihydroxy alcohols
• C. Trihydroxy alcohol
• D. All of the above

Explanation: Waxes are esters formed from the reaction of fatty acids with long-chain monohydroxy alcohols, which have one hydroxyl group.

• A. Presence of single bonds between carbon atoms.
• B. Presence of Double bonds between carbon atoms
• C. Presence of Triple bonds between carbon atoms.
• D. Absence of bond between carbon atoms.

Explanation: Saturated fatty acids contain a single bond between the carbon atoms, this is a fact

• A. Palmitic acid
• B. Archachidic acid
• C. Stearic acid
• D. Oleic acid

Explanation: Option D is correct. Oleic acid is the unsaturated fatty acid. Fatty acids are classified into saturated and unsaturated fatty acids.

• A. Inside the nucleus
• B. Inside the cytoplasm
• C. Inside the plasma membrane
• D. inside the mitochondrial matrix

Explanation: Option C is correct.Phospholipids arrange themselves in a bilayer in the plasma membrane of a cell.

• A. Abdominal duct
• B. Thoracic duct
• C. Femoral duct
• D. Subclavian duct

Explanation: The thoracic duct is the largest lymphatic duct in the body. It collects lymph from most of the body (except the right arm and right side…

• A. Tonsils
• B. Pancreas
• C. Spleen
• D. Thymus

Explanation: Option C is correct.The largest body of lymphoid tissue in the human body is the spleen.

• A. Biochemist
• B. Microbiologist
• C. Physiologist
• D. Mycologist

Explanation: Laiba is a biochemist who is trying to determine the percentage of protein, a biomolecule, in beans.

• A. Ornithology
• B. Ichthyology
• C. Herpetology
• D. Ethology

Explanation: The correct answer is Ichthyology, which is the branch of zoology dedicated to the study of fishes.

• A. Dominant
• B. Recessive
• C. Phenotype
• D. Alleles

Explanation: Fact. "Allele" is the word that we use to describe the alternative form or versions of a gene.

• A. Polygenic alleles
• B. Multigenic alleles
• C. Multiple alleles
• D. Heterogenic alleles

Explanation: In polygenic inheritance, each allele has a cumulative or additive effect on the phenotype thus generating continuous variation, e.g.

• A. 9:3:3:1
• B. 9:3:4
• C. 1:2:1
• D. 2:11

Explanation: The correct ratio for demonstrating the law of independent assortment is 9:3:3:1.

• A. Hypostatic
• B. Epistatic
• C. Hemistatic
• D. Neostatic

Explanation: Epistatic is the gene that masks the expression of an allele at a separate locus.

• A. All red
• B. All white
• C. All pink
• D. 1, red, 2, pink & 1 white ratio

Explanation: When red and white color flowers in Mirabilis jalapa (Four O'Clock Flower) are crossed, the F1 generation will typically display an…

• A. Tongue rolling
• B. Diabetes
• C. Skin colour
• D. Eye colour

Explanation: This mcq can only be solved by elimination trick. Tongue rolling is controlled by dominant trait while skin colour is a polygenic trait…

• A. Option A: Complete-dominance
• B. Option B: Incomplete dominance
• C. Option C: Co-dominance
• D. Option D: None

Explanation: The correct answer is Option B: Incomplete dominance. In cases of incomplete dominance, the heterozygous offspring exhibit a phenotype…