Which one of the following is NOT true of mitotic cell division ?
- A.The nuclei of the two daughter cells in mitosis have same number of chromosomes
- B.Replacement of cell and tissue repairing is possible through mitosis
- C.Asexual reproduction in eukaryotes is done by mitosis
- D.The cells become haploid as a result of mitosis
Correct answer
Explanation
The correct answer is D, The cells become haploid as a result of mitosis. Mitosis keeps the chromosome number unchanged, so it never makes cells haploid; that is the work of meiosis.
In mitosis one parent cell divides once and gives two daughter cells that are genetically identical to it. A diploid human body cell with 46 chromosomes produces two cells with 46 each. This is why mitosis drives growth, the replacement of worn-out cells and the healing of wounds. Meiosis, by contrast, has two divisions and halves the number, producing haploid gametes with 23 chromosomes, which restore the diploid number at fertilisation.
Option A is true, because both daughter nuclei receive the same, full set of chromosomes. Option B is true, because skin, blood and gut cells are replaced and tissues repaired by mitosis. Option C is true, because budding in yeast and vegetative propagation in plants rely on mitosis.
Exam tip: mitosis = equational division (2n to 2n), meiosis = reductional division (2n to n).
Practice Questions
View allThe fact that the planets move around the Sun, not in circles but in ellipses, was first demonstrated by
- A.Galileo
- B.Martin Luther
- C.Johannes Kepler
- D.Copernicus
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In 1609 Kepler showed that the planets move around the Sun in elliptical orbits, with the Sun at one focus of the ellipse.
Read the full explanation →Which one of the following statements is correct?
- A.Urea is produced in liver.
- B.Urea is produced in blood.
- C.Urea is produced from digestion of starch.
- D.Urea is produced in lung and kidney.
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Liver cells turn the toxic ammonia released from the breakdown of amino acids into urea through the ornithine cycle, also called the urea cycle.
Read the full explanation →Which one of the following is the correct sequence of passage of light in a compound microscope?
- A.Condenser-Objective lens-Eyepiece-Body tube
- B.Objective lens-Condenser-Body tube-Eyepiece
- C.Condenser-Objective lens-Body tube-Eyepiece
- D.Eyepiece-Objective lens-Body tube-Mirror
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Light passes through the condenser to the specimen, is picked up by the objective lens, travels up the body tube and reaches the eye through the eyepiece.
Read the full explanation →Which one of the following statements regarding haemoglobin is correct?
- A.Haemoglobin present in RBC can carry only oxygen but not carbon dioxide.
- B.Haemoglobin of RBC can carry both oxygen and carbon dioxide.
- C.Haemoglobin of RBC can carry only carbon dioxide.
- D.Haemoglobin is only used for blood clotting and not for carrying gases.
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It binds oxygen at its iron-containing haem groups and carries some carbon dioxide on its protein chains. Each haemoglobin molecule has four polypeptide chains and four haem groups, and each haem iron can hold one oxygen molecule, forming oxyhaemoglobin in the lungs.
Read the full explanation →Which one of the following statements regarding histone proteins is correct?
- A.Histones are proteins that are present in mitochondrial membrane.
- B.Histones are proteins that are present in nucleus in association with DNA.
- C.Histones are proteins associated with lipids in the cytosol.
- D.Histones are proteins associated with carbohydrates in the cytosol.
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They are the proteins around which DNA winds to form chromatin in the nucleus of eukaryotic cells. Histones are small basic proteins, rich in the positively charged amino acids lysine and arginine, which attract the negatively charged phosphate groups of DNA.
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