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

In man, which of the following genotypes and phenotypes may be the correct result of aneuploidy in sex chromosomes?

  1. 22 pairs + XXY males

  2. 22 pairs + XX females

  3. 22 pairs + XXXY females

  4. 22 pairs + Y females
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The condition of chromosomal change which involve the loss or gain of single chromosome is called aneuploidy. Genotype 22 pairs + XXY males shows the condition of Klinefelter's syndrome. Klinefelter's syndrome was studied in 1942 by an American Dr. H.F. Klinefelter. The patient of this syndrome have an extra X chromosome, hence the genotype is XXY instead of normal XY and patient has 47 chromosomes instead of 46. 

Multiple choice

The carriers of hereditary material are

  1. chromosome

  2. gene

  3. gametes

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

The carrier of heredietary metarial is gene. It is a functional unit of heredietary material. The term gene was proposed in 1909 for the first time by Johannsen. Gene's is also the smallest unit that could undergo a mutational change or could take part in recombination. 

Multiple choice

In the recent past, human chromosomes have been studied by a technique, using specific fluorescent dyes, known as

  1. dyeing technique

  2. banding technique

  3. ultra dyeing technique

  4. karyotyping technique
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In recent past human chromosome have been studied by a techinque using specific, often flouroscent dyes, known as karyotyping technique. The term karyotype is given to the group of characteristics that identifies a particular chromosome set and is usually represented by a diagram called idiogram.

Multiple choice

The sex chromosome in females are

  1. XX

  2. XY

  3. YY

  4. XXY
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The sex chromosomes in females are XX. in female individuals, there are 22 pairs of autosomes and one pair of sex chromosome (22 pair + XX).

Multiple choice

Which of the following statements regarding Euchromatin is/are correct?

  1. It is found in parts of chromosomes containing many genes.

  2. It is loosely packed in loops of 30-nm fibres.

  3. It is separated from adjacent heterochromatin by insulators.

  4. All are correct.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Euchromatin is a lightly packed form of chromatin (DNA, RNA and protein) that is enriched in genes ,and is often (but not always) under active transcription. Euchromatin comprises the most active portion of the genome within the cell nucleus. 92% of the human genome is euchromatic. All the statements given above are correct.

Multiple choice

Bread wheat is

  1. tetraploid

  2. hexaploid

  3. diploid

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

T. aestivum is bread wheat and is a hexaploid species.

Multiple choice

What happens during karyokinesis?

  1. Protoplasm divides into two parts.

  2. Nucleus divides into two parts.

  3. Cytoplasm divides into two parts.

  4. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Karyokinesis is the division of a cell nucleus during mitosis.

Multiple choice

In which phase of nuclear division is paranemic coiling found?

  1. Meiotic prophase

  2. Mitotic prophase

  3. Amitotic division

  4. Crossing over
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In mitosis, plectonemic coiling takes place, in which sister chromatids are tightly coiled upon each other and are not easily separable. Paranemic coiling is found in meiosis.

Multiple choice

In gynadromorphs, as seen in Drosophila (fruit fly),

  1. one half of the body is male and the other half is female

  2. right half of the body is normal and left half is like that of a dwarf

  3. right half of the body is dwarf and the left half is normal

  4. one half of the body is dwarf and the other half is like that of a giant
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In gynadromorphs, as seen in Drosophila (fruit fly), one half of the body is male and the other half is female.