Biology
Cell Cycle and Chromosomes
1,219 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
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chromomere
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secondary constriction
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telomere
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telocentric
C
Correct answer
Explanation
Chromosomal end is known as telomere.
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XX - XY
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XX - XO
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ZZ - ZW
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XY - XX
B
Correct answer
Explanation
XX -XO type of sex determination is found in female grasshoppers. They have two X chromosomes, whereas males have only one. Female grasshoppers are described as being XX and males as XO.
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trisomy of sex chromosome
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trisomy of 11th chromosome
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trisomy of 21st chromosome
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trisomy of 12th chromosome
C
Correct answer
Explanation
Trisomy of 21st chromosome causes Down's syndrome.
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cytokinesis
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karyokinesis
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chromosomal movement
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cell elongation
A
Correct answer
Explanation
In cell division, phragmoplasts are concerned with cytokinesis.
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hetereochromatin
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centromere
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chromonemata
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chromomere
D
Correct answer
Explanation
Chromomere is not involved in crossing over during meiosis.
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44 autosomes and XXY sex chromosomes
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44 autosomes and XO sex chromosomes
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44 autosomes and XYY sex chromosomes
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44 autosomes and XXX sex chromosomes
B
Correct answer
Explanation
This is Turner's syndrome.
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Y chromosome
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X and Y chromosomes, the male being XY
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the number of X chromosomes, the male being XO
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Z and W chromosomes, the male being ZZ
B
Correct answer
Explanation
The sex of a fruitfly is determined by X and Y chromosomes, the male being XY.
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translocation
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deletion
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frame shift
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duplication
A
Correct answer
Explanation
Sometimes, a segment of a chromosome detaches and unites with another non-homologous chromosome. Such an inter-chromosomal rearrangement is called translocation.
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2 pair
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3 pair
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4 pair
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8 pair
C
Correct answer
Explanation
Drosophila has 3 pairs of autosome and 1 pair of allosome.
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in order to maintain the ploidy level of the progeny as that of parents
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in order to shorten the cell cycle in meiosis
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in order to release it from the cell cycle
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in order to help the cell to divide into four
A
Correct answer
Explanation
G2 phase is responsible for replication of the chromatin material resulting in the formation of similar sister homologous chromosomes, which maintain the ploidy status in the daughter nucleus, as in mitosis and if it occurs so in meiosis then the number of chromosomes will be doubled in the zygote and consequently in the progeny as that of parents and ploidy will be doubled in the progeny with each generation resulting in genetic abnormality.
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It mediates in pairing of homologous chromosome during prophase 1 of meiosis.
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It helps in chiasma formation between chromosomes.
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It mediates in pairing of homologous chromosomes during prophase 2 of meiosis.
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It mediates in pairing of homologous chromosomes during prophase of mitosis.
A
Correct answer
Explanation
During prophase 1 of meiosis, homologous chromosome pair comes closer together and they are held in pairs with the help of protein structures called synaptonemal complex.
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Haploid is half the number of genome in an individual while monoploid is presence of just one set of chromosomes.
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Haploid is n and monoploid is also n.
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Haploid is 2n and monoploid is n.
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Haploid is half the number of genome in an individual while monoploid is full set of genome.
A
Correct answer
Explanation
The gametes of an individual are haploid, i.e. they carry half the number of genome, similarly the other half comes from the gametes of the contributing parents, so that the number of genome is restored in the progeny to the parental level. Examples- Haploid of 2n is n, haploid of 4n is 2n. Similarly haploid of 6n is 3n. Monoploid means presence of just one set of chromosomes in the genome of an individual. Examples- Some species of potatoes are monoploid n. Humans are diploid, i.e. 23 (n) + 23 (n) = 46 (2n).
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telocentric
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chromomere
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telomere
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secondary constriction
C
Correct answer
Explanation
Chromosomal ends are known as telomere. This is the correct answer.
C
Correct answer
Explanation
The process of DNA replication, which we will describe is completed by the end of S phase.
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Leptotene, pachytene, zygotene, diakinesis and diplotene
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Leptotene, zygotene, diakinesis, diplotene and pachytene
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Zygotene, diakinesis, diplotene, pachytene and leptotene
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Leptotene, zygotene, pachytene, diplotene and diakinesis
D
Correct answer
Explanation
The correct sequence of prophase I is leptotene, zygotene, pachytene, diplotene and diakinesis.