Biology

Cell Cycle and Chromosomes

1,348 Questions

Explore a curated list of questions covering the cell cycle, mitosis, and meiosis. Topics include DNA replication, chromosomal structures, and genetic disorders. This material is essential for students preparing for biology and general science competitive exams.

Cell cycle eventsDNA replicationMeiosis processChromosomal structuresGenetic disorders

Cell Cycle and Chromosomes Questions

Multiple choice

The molecular change in chromosomes is called

  1. chromosomal aberration

  2. point mutation

  3. spontaneous mutation

  4. induced mutation

  5. transformation
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

It is the change in the number or arrangement of nucleotides. It is the transfer of DNA from one bacterium to the other.

Multiple choice

Which of the following malignancies is due to the chromosomal translocation?

  1. Lung cancer

  2. Chronic lymphoblastic leukemia

  3. Acute myelocytic leukemia

  4. Chronic myelogenous leukemia

  5. Bladder cancer

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Chronic myelogenous leukemia (CML) is caused by the Philadelphia chromosome, resulting from a reciprocal translocation between chromosomes 9 and 22 - t(9;22)(q34;q11). This creates the BCR-ABL fusion gene with constitutive tyrosine kinase activity. Other malignancies listed have different causes (lung cancer from mutations, CLL from various genetic changes, AML from multiple mutations, bladder cancer from environmental factors).

Multiple choice

Screening test for aneuploidy syndromes is

  1. Western blot

  2. Northern blot

  3. Southern blot

  4. FISH

  5. ELISA
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

FISH (Fluorescence In Situ Hybridization) is the standard screening test for aneuploidy syndromes like Down syndrome, Turner syndrome, etc. It uses fluorescent probes to detect chromosomal abnormalities.

Multiple choice

There are numerous techniques in cytogenetics to investigate the different features of chromosomes within a cell. Which of the following is a frequently used fluorescent pattern acquired employing quinacrine for staining the chromosomes?

  1. C-banding

  2. R-banding

  3. G-banding

  4. Q-banding

  5. T-banding
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Q-banding is a fluorescent pattern obtained using quinacrine for staining. The pattern of bands is very similar to that seen in G-banding. They can be recognised by a yellow fluorescence of differing intensity. Most part of the stained DNA is heterochromatin. Quinacrin (atebrin) binds both regions rich in AT and in GC, but only the AT-quinacrin-complex fluoresces.

Multiple choice

Centromere proteins are a group of proteins, which either form or mediates the function of centromeres. Which of the following centromere proteins is predominately essential for keeping proper kinetochore size?

  1. Centromere protein

  2. Centromere protein B

  3. Centromere protein C 1

  4. Centromere-associated protein E

  5. Centromere protein F
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Centromere protein C 1 is a centromere autoantigen and a component of the inner kinetochore plate. The protein is required for maintaining proper kinetochore size and a timely transition to anaphase. A putative pseudogene exists on chromosome 12.

Multiple choice

Chromosomes that do not take part in the determination of sex are called autosomes.

Of the total pairs of chromosomes in a human being, how many pairs are autosomes?

  1. 1 pair

  2. 22 pairs

  3. 8 pairs

  4. 16 pairs

  5. 2 pairs
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Chromosomes that do not take part in the determination of sex are called autosomes. There are 22 pairs of autosomes in a human. This is the correct option. A human being has 22 pairs of autosomes and only 1 pair of allosomes.

Multiple choice

The sex determining chromosomes in a human male are ______ and the sex determining chromosomes in a human female are _______.

  1. XX, XY

  2. XY, XX

  3. XX, XO

  4. XO, XX
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Human females have two of the same kind of sex chromosomes (XX), while males have two distinct sex chromosomes (XY). The XY chromosomal cells create testosterone and anti-müllerian hormone to turn the genderless sex organs into male. With females, their cells excrete estrogen, driving the body down the female pathway. Thereby, determining the sex of the baby.