All Free Biology MCQs with Answers
Every Biology question in the bank, across all chapters, each with the correct answer and a written explanation. Free and unlimited, with no account needed.
19,844 questions · page 929 of 993
- A. Lytic Phage
- B. Lysogenic Phage
- C. Prophage
- D. Bacteriophage
Explanation: Lytic phages take over the machinery of the cell to make phage components.
Correct answer: Lytic Phage- A. Bacteria
- B. Viruses
- C. Protists
- D. Protozoans
Explanation: Viruses are an exception to cell theory since they are within the boundary of living and non-living.
Correct answer: Viruses- A. 1990
- B. 2001
- C. 1980
- D. 1995
Explanation: The World Health Organization (WHO) declared that smallpox was completely eradicated in 1980.
Correct answer: 1980- A. Cytoplasm
- B. Nucleus
- C. Microtubules
- D. Golgi complex
Explanation: There is no outer covering in such viruses and so, their nucleocapsids are assembled in the cytoplasm.
Correct answer: Cytoplasm18565. When a haemophilic carrier woman marries a normal man, who among her offspring may be affected?
- A. All her children
- B. All her daughters
- C. Half of her sons
- D. None of these options
Explanation: Haemophilic female = XH Xh Normal male= XH Y Referring to the Punnett square, Half of daughters are affected as a carrier of haemophilia…
Correct answer: Half of her sons- A. 25%
- B. 50%
- C. 75%
- D. 100%
Explanation: Haemophilia is a sex-linked recessive disorder, usually an inherited bleeding disorder in which the blood does not clot properly.
Correct answer: 50%- A. Haemophilia
- B. Colour blidness
- C. Hypophosphatemic ricket
- D. TFM syndrome
Explanation: Hypophosphatemic rickets is an X-linked dominant trait in which excessive loss of phosphate in the urine leads to poorly formed bones…
Correct answer: Hypophosphatemic ricket- A. 1.0
- B. 0.75
- C. 0.50
- D. 0.25
Explanation: Males have 1 X chromosome and 1 Y chromosome, and females have 2 X chromosomes.
Correct answer: 0.50- A. Homozygous
- B. Hemizygous
- C. Heterozygous
- D. Incomplete dominance
Explanation: Hemizygous means having only a single copy of a gene instead of the customary two copies.
Correct answer: Hemizygous- A. False: Females can't have haemophilia
- B. False: Haemophilia wasn't diagnosed until then
- C. True: Females can have haemophilia if both the mother and father were affected
- D. True: Females can have haemophilia if any of the parent were affected
- E. None of the answers are correct
Explanation: Explanation for this question will be added soon.
Correct answer: True: Females can have haemophilia if both the mother and father were affected- A. 0%
- B. 25%
- C. 50%
- D. 100%
Explanation: X chromosome comes from the female and X or Y comes from the man. if the man is normal then the disease will not express in the daughter.
Correct answer: 0%18572. Which of the following traits is transmitted directly from an affected father to only his son?
- A. Autosomal
- B. X-linked
- C. Y-linked
- D. X-Y linked
Explanation: Y-linked traits are passed from father to son through the Y chromosome.
Correct answer: Y-linked- A. Translation
- B. Duplication
- C. Replication
- D. Reverse Transcription
Explanation: Reverse transcription is a process by which the DNA molecule is formed from the RNA template and the process is catalyzed by the enzyme…
Correct answer: Reverse Transcription- A. Ligase
- B. Reverse Transcriptase
- C. RNA Polymerase
- D. DNA Polymerase
Explanation: HIV is a retrovirus. Its genome consists of RNA molecules, and it possesses a 'reverse transcriptase enzyme', which allows the virus to…
Correct answer: Reverse Transcriptase- A. Vacuole, Chloroplast, and ribosomes
- B. Chloroplasts, Microtubules, and peroxisomes
- C. Chloroplast, Cell Wall, and vacuole
- D. Chloroplast, Cell Wall, Mitochondria
Explanation: All mentioned organelles are absent in animal cells and are only present in plant cells hence this option is correct.
Correct answer: Chloroplast, Cell Wall, and vacuole- A. Proteins
- B. Cholesterols
- C. Cytoskeleton
- D. Phospholipids
Explanation: The fundamental structure of the membrane is the phospholipid bilayer, which forms a stable barrier between two aqueous compartments.
Correct answer: Phospholipids- A. Centrioles
- B. Rough Endoplasmic Reticulum
- C. Microtubules
- D. Ribosomes
Explanation: Centrioles are present in (1) animal cells and (2) the basal region of cilia and flagella in animals and lower plants (e.g.
Correct answer: Centrioles- A. Passive transport
- B. Active transport
- C. Facilitated diffusion
- D. Filtration
Explanation: Active transport requires the expenditure of energy in the form of ATP to move molecules against their concentration gradient, from an…
Correct answer: Active transport- A. Phospholipids
- B. Globular proteins
- C. Glycolipids and glycoproteins
- D. Cholesterol
Explanation: Glycolipids and glycoproteins presence are the basic factors for differentiating cells
Correct answer: Glycolipids and glycoproteins- A. Sciatica.
- B. Disc slip.
- C. Spondylosis.
- D. Rickets.
Explanation: c) Spondylosis: This is the correct option. Spondylosis is a degenerative condition that affects the spine, leading to the deterioration…
Correct answer: Spondylosis.