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 membrane bounding a chromosome is called

  1. chromosomal membrane

  2. pellicle

  3. tonoplast

  4. genetic coat
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Each chromosome is bounded by a membrane called pellicle. It is very thin and is formed of achromatic substance.

Multiple choice

A holocentric chromosome has

  1. only two centromeres

  2. chromosome without centromere

  3. a large number of centromeres scattered throughout the length of the chromosome

  4. only one centromere
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A holocentric chromosome is where a large number of centromeres are scattered throughout the length of the chromosome.

Multiple choice

Which of the following is a characteristic feature of metaphase?

  1. The chromosomes are single and condensed.

  2. The chromosomes are in the form of chromonema.

  3. A typical chromosome consists of two chromatids.

  4. Chromosomes bear bead-like structures called chromomeres.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A chromosome consists of two chromatids at metaphase.

Multiple choice

What are chromosomes composed of?

  1. Only DNA

  2. DNA and Proteins

  3. DNA, Proteins and RNA

  4. DNA and RNA
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Chromosome is made up of DNA, histone protein and some chromosomal RNAs which may have a role in transcription.

Multiple choice

Colchicine helps in

  1. protein synthesis

  2. DNA replication

  3. doubling of chromosomes

  4. spindle formation
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Colchicine helps in doubling of chromosomes.

Multiple choice

In a dividing cell the meiosis I is a reductional division and the meiosis II is equational division due to the

  1. pairing of homologous chromosomes

  2. crossing over

  3. separation of chromatids

  4. disjunction of homologous chromosomes

  5. nondisjunction of homologous chromosomes
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

August Weismann in 1887 predicted that the number of chromosomes must be reduced by one half during gamete formation. The two divisions of meiosis are called the first and the second mieiotic divisions. In meiosis I, the number of chromosomes are reduced from diploid to haploid condition whereas in meiosis II, the two chromatids of each chromosome separate from each other and go to separate daughter cells, as a result the number of chromosomes remains the same as produced by meiosis – I.

Multiple choice

At which stage of the cell cycle do histone proteins synthesise in a eukaryotic cell?

  1. During the S-phase

  2. During the prophase II

  3. During the telophase

  4. During the G-2 stage of prophase

  5. During the metaphase II
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

During the S phase or synthetic phase the replication of DNA takes place. For replication of DNA histone proteins are required, so they are also synthesised during this phase. It takes about 30%-50% of the total cell cycle.