All Free Biology MCQs with Answers

• A. Even though it was a winter wedding, the sun smiled down on proceeding all day.
• B. Even though it was a winter wedding, the sun smiled down proceedings all day.
• C. Even though it was a winter wedding, sun smiled down on proceedings all day.
• D. Even though it was a winter wedding, the sun smiled down on proceedings all day.

Explanation: The sentence is structured correctly, using the phrase "the sun smiled down on proceedings" to describe the weather during the wedding.

• A. 12
• B. 14
• C. 16
• D. 18Preparing For College Admissions Tests

Explanation: Humans have 12 pairs of ribs, and the upper 7 pairs attach directly to the sternum, so the number of true ribs is 7 pairs x 2 ribs per…

• A. 33
• B. 20
• C. 15
• D. 32Health

Explanation: Children have 20 primary teeth, arranged as 10 in the upper jaw and 10 in the lower jaw.

• A. Two identical light chains only
• B. Two identical heavy chains only
• C. Two identical light and two identical heavy chains
• D. Two identical light chains and two non-identical heavy chains

Explanation: An antibody molecule, also known as an immunoglobulin, is a Y-shaped protein that plays a critical role in the immune response by…

• A. The variable sequence of amino acids is longer.
• B. The variable sequence of amino acids is shorter.
• C. Both variable and constant amino acid sequences have equal length.
• D. Only the variable sequence of amino acids occurs.

Explanation: The light chain of an antibody consists of both variable and constant regions.

• A. Mucus membrane
• B. WBCs
• C. Ciliated cells
• D. RBCs

Explanation: RBCs have no role in immunity. RBCs (red blood cells) do not protect the body against the entrance of germs.

• A. Thymus
• B. Lymph nodes
• C. Adrenal glands
• D. Lymphatic vessels

Explanation: Lymph nodes house large populations of B and T lymphocytes for immune defense.

• A. Use of polio vaccine
• B. Passing of certain antibodies to the foetus by the pregnant women
• C. Inoculation of antitoxin in the case of puncture wound
• D. Both B and C

Explanation: Passive immunity is provided when a person is given antibodies to a disease rather than producing them through his or her own immune system.

• A. Tears
• B. Mucous membranes
• C. Ciliated cells
• D. Red blood cells,

Explanation: Red blood cells are responsible for transporting O2 via hemoglobin stored in them from the lungs to the body's cells and tissues.

• A. Red blood cells
• B. White blood cells
• C. Platelets
• D. Plasma

Explanation: "White blood cells" (also known as leukocytes) are a crucial component of the immune system and are responsible for defending the body…

• A. A cells
• B. B cells
• C. F cells
• D. T cells

Explanation: B lymphocytes recognize antigens and differentiate into plasma cells that secrete antibodies.

• A. I have brought some footballs with that the children will play.
• B. I have brought some footballs that the children will play with.
• C. I have brought some footballs with whom the children will play.
• D. I have brought some footballs whose that the children will play with.

Explanation: This option is correct. The relative pronoun "that" introduces the relative clause "that the children will play with," and the preposition…

• A. I gave in because I didn't have the strength to argue.
• B. I gave in because I didn't have strength to argue.
• C. I gave in because I didn't have a strength to argue.
• D. I gave in because I don't have strength to argue.

Explanation: The sentence describes a situation where the speaker lacked the energy or courage to continue arguing, and "the strength" is the correct…

• A. Headmaster - Mr. welldon, however, took a broadminded view of my Latin prose.
• B. Headmaster- Mr. welldon, however, took a broadminded view of my Latin prose.
• C. Headmaster, Mr. welldon. however, took a broadminded view of my Latin prose.
• D. Headmaster, Mr. welldon, however, took a broadminded view of my Latin prose.

Explanation: This sentence is identical to and is correct in its use of commas to set off the appositive "Mr.

• A. Glucose and fructose both are monosaccharides
• B. The natural glucose and fructose are D-forms
• C. The solution having equal molecules of D-glucose and D-fructose is termed inverted sugar
• D. Aldohexoses exist in 2 optical forms

Explanation: This statement is not true. Aldohexoses, including glucose, exist in multiple optical forms.

• A. Two factors for the same trait separate in the production of gametes
• B. Two different traits will be inherited independently of each other
• C. Gametes are produced by meiosis
• D. All of the above

Explanation: The Law of Segregation states that alleles segregate randomly into gametes: When gametes are formed, each allele of one parent segregates…

• A. Form of appearance of a trait
• B. Genetic complement of an individual
• C. Partner of gene on chromosomes
• D. None of the above

Explanation: The external appearance of an individual trait is known as 'Phenotype'.

• A. Obtained by self fertilization
• B. It is homozygous trait
• C. It produces homozygous offspring
• D. All of the above

Explanation: A true-breeding variety upon self-fertilization always produced offspring identical to the parents.

• A. Haemophilia
• B. Colour blindness
• C. Hypophosphatemia
• D. TFM syndrome

Explanation: Hereditary hypophosphatemic rickets with hypercalciuria (HHRH) is a rare bone disorder characterized by symptoms associated with…

• A. Different alleles of a gene are both expressed in heterozygous condition
• B. One allele (R) is completely dominant over the other (r) and the presence of the recessive allele is functionally hidden, so the heterozygote (Rr) has the same round phenotype as the (RR) homozygote.
• C. The phenotype of the heterozygote is intermediate between phenotypes of the two homozygotes
• D. Gene mutations may produce many different alleles of a gene

Explanation: Complete dominance is a form of dominance in a heterozygous condition wherein the allele that is regarded as dominant completely masks the…