All Free Biology MCQs with Answers

• A. must
• B. who
• C. from
• D. the

Explanation: The error in the sentence is in option (B) "who." It should be corrected to "that" to properly refer to a work area.

• A. Oh
• B. Hi
• C. Bravo
• D. Regrettably

Explanation: Alas is a term used to express grief, pity or concern thus, regrettably.

• A. Only conclusion I follows
• B. Only conclusion II follows
• C. Neither I nor II follows
• D. Both conclusions I and II follow

Explanation: The statements establish that stresses and strains are an inherent part of life and that they have a negative impact. It logically follows that avoiding these adverse effects would be beneficial, supporting Conclusion II. Conclusion I is an extreme, subjective judgment not supported by the statements.

• A. 18
• B. 15
• C. 21
• D. 20

Explanation: This is an alternating series. The first series (1, 3, 6, 10, 15) increases by +2, +3, +4, +5. The second series (7, 9, 12, 16) increases by +2, +3, +4. The next term belongs to the second series, so it is 16 + 5 = 21.

• A. True
• B. False
• C. Uncertain
• D. None of these

Explanation: The first two statements establish the speed order: Lily > Mara > Gail. Based on this, Lily is the fastest runner. Therefore, the statement "Gail runs faster than Lily" must be false.

• A. Ribosome
• B. Nucleoplasm
• C. Cytoplasm
• D. Nucleolus

Explanation: The maximum formation of mRNA occurs in the nucleolus. The nucleolus is a dense region within the nucleus that is responsible for ribosome biogenesis. The mRNA is transcribed from DNA in the nucleus by an enzyme called RNA polymerase. The mRNA is then transported out of the nucleus to the cytoplasm, where it is translated into proteins by ribosomes. The amount of mRNA formation varies depending on the cell type and the cell's needs. For example, cells that are rapidly dividing or that are producing a lot of protein will have higher rates of mRNA formation. The other options that you listed are not as involved in mRNA formation:Ribosomes are the organelles where protein synthesis takes place. They are located in the cytoplasm of the cell.The cytoplasm is the watery part of the cell that is located outside of the nucleus. It contains a variety of organelles, including the ribosomes.The nucleoplasm is the jelly-like substance that fills the nucleus of a cell. It contains the cell's DNA, as well as a variety of proteins and other molecules that are involved in gene expression.

• A. A Ribosome with several subunits
• B. Ribosomes attached to each other in a linear arrangement
• C. Several Ribosomes attached to a single mRNA
• D. Many Ribosomes attached to a strand of endoplasmic reticulum

Explanation: Ribosomes may occur in rosettes or helical groups called polyribosomes or polysomes (Gk. Poly- many, soma-body). The different ribosomes of a polyribosome are connected with a 10 -20 Å thick strand of messenger or mRNA and its maintenance requires energy. Polyribosomes are formed during periods of active protein synthesis when a number of copies of the same polypeptide are required.

• A. Genome, chromosome, gene, nucleotide
• B. Chromosome, genome, nucleotide, gene
• C. Chromosome, gene, genome, nucleotide
• D. Genome, chromosome, nucleotide, gene

Explanation: In the genome, all the genes are contained in a single set of chromosomes. The instructions in our genome are present in the form of DNA. DNA has a complicated structure in the form of a double helix. Single strands of DNA are coiled up into structures called chromosomes. Within the chromosomes, segments of DNA are "read" together to form genes. Thus, a gene is a segment of DNA or chromosome situated at a specific locus (gene locus) that carries coded information associated with a specific function and can undergo crossing over as well as mutation. A nucleotide is the basic unit of DNA made up of a pentose sugar, phosphoric acid, and a nitrogenous base.

• A. 60%
• B. 80%
• C. 40%
• D. Very small

Explanation: Chromosomes are composed of DNA and histone proteins. Most are about 40 % DNA and 60 % histone proteins. A significant amount of RNA is also associated with the chromosomes.

• A. Euchromatin
• B. Bio Chromatin
• C. Heterochromatin
• D. Nuclear Chromatin

Explanation: Heterochromatin and euchromatin are two types of chromatin. The key difference between heterochromatin and euchromatin is the packaging. Heterochromatin is the highly packed form of chromatin while euchromatin is the loosely packed form of chromatin and condensed only during cell division.