Free Chromosomes MCQs with Answers
633 Chromosomes MCQs from Biology, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Chromosomes are DNA-protein structures that carry genes and become visible during cell division. Coverage includes chromatin, centromeres, sister chromatids, homologous chromosomes, chromosome number, and the distinction between diploid and haploid cells, with links to DNA replication, mitosis and meiosis.
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633 questions · page 15 of 32
- A. A gene is a sequence of nucleotides in DNA.
- B. A gene is the basic unit of heredity.
- C. A gene codes for a molecule that has a function.
- D. A gene expresses to form chromosomes.
Explanation: All statements except D are correct. Genes do not express themselves to form chromosomes.
Correct answer: A gene expresses to form chromosomes.- A. Allele and allele
- B. Allele and gene
- C. Gene and gene
- D. Mutation and gene
Explanation: These are alleles for purple and white flowers. It can be confused as genes sometimes which is wrong because here we can see the two forms…
Correct answer: Allele and allele- A. Chromatin
- B. chromatids
- C. centromere
- D. polar dyes
Explanation: A chromatid is one of two identical halves of a replicated chromosome. During cell division, the chromosomes first replicate so that each…
Correct answer: chromatids- A. 120
- B. 240
- C. 40
- D. 160
Explanation: If an animal cell has 80 chromosomes in its gametes, it would have double that number in its somatic cells (body cells).
Correct answer: 160- A. 3000
- B. 4000
- C. 2500
- D. 3500
Explanation: In humans the telomere sequence is TTAGGG. This sequence is usually repeated about 3,000 times and can reach up to 15,000 base pairs in…
Correct answer: 3000- A. Pseudoautosomal
- B. Sex linked
- C. Both a & b
- D. None of the above
Explanation: X-linked, as related to genetics, refers to characteristics or traits that are influenced by genes on the X chromosome.
Correct answer: Sex linked- A. DNA from mRNA
- B. An artificial DNA
- C. Single stranded DNA
- D. A small segment of chromosomal DNA
Explanation: A complementary DNA molecule or cDNA is, by definition, a DNA copy of a messenger RNA or mRNA molecule, produced by reverse transcriptase.
Correct answer: DNA from mRNA- A. 100% heavy duplex
- B. 100% hybrid duplex
- C. 50% hybrid duplex and 50% heavy duplex
- D. 50% hybrid duplex and 50% light duplex
Explanation: After two rounds of replication, half of the duplexes will be hybrid i.e.
Correct answer: 50% hybrid duplex and 50% light duplex- A. GGGAUCUC
- B. GGGATCTC
- C. GGAAUCUC
- D. GGGGTCTC
Explanation: C pairs with G, A pairs with T in DNA while A pairs with U in RNA. The question asks for the corresponding mRNA sequence, after…
Correct answer: GGGAUCUC- A. Adenosine
- B. NAD
- C. ATP
- D. Guanine
Explanation: ATP is a nucleotide, as it contains a pentose sugar, an adenine base, and three phosphate groups.
Correct answer: ATP- A. Adenine, Guanine, and Cytosine
- B. Guanine and Cytosine
- C. Adenine and Guanine
- D. Adenine and Thymine
Explanation: Purine bases are adenine and guanine, while pyrimidine bases are thymine, cytosine, and uracil.
Correct answer: Adenine and Guanine- A. Transcription
- B. Translation
- C. Proofreading
- D. DNA Replication
Explanation: Transcription, is when RNA polymerase makes a copy of a gene on a template DNA strand in the nucleus; this copy is messenger RNA.
Correct answer: Transcription- A. 93
- B. 330
- C. 331
- D. 993
Explanation: Codon consists of three nucleotides, and each codon corresponds to a single amino acid.
Correct answer: 330- A. Dispersive idea
- B. Conservative idea
- C. Disruptive idea
- D. Semi-conservative idea
Explanation: It is 'dispersive replication', which involves each daughter strand containing both parental and new DNA, as the old DNA is broken up and…
Correct answer: Dispersive idea295. Extremely long molecule of DNA that is tightly folded to fit inside the cell component is called?
- A. Nucleus
- B. Chromosome
- C. Chromatin body
- D. Chromatid
Explanation: In the nucleus of each cell, the DNA molecule is packaged into thread-like structures called chromosomes.
Correct answer: Chromosome- A. Alzheimer's disease
- B. Parkinson's disease
- C. Anemia
- D. Hemolytic anemia
Explanation: Mutations probably include a combination of age-related changes in the brain along with genetic, environmental, and lifestyle factors.
Correct answer: Hemolytic anemia- A. 34 nanometer
- B. 3.4 Angstrom
- C. 3.4 nanometer
- D. 34 micrometers
Explanation: At a distance of 3.4nm, the double helix DNA produces one full turn. Each full turn of DNA consists of 10 base pairs.
Correct answer: 3.4 nanometer- A. Uracil, Cytosine and Thymine
- B. Cytosine, Guanine and Uracil
- C. Adenine and Guanine
- D. Cytosine, Adenine and Thymine
Explanation: The pyrimidines, Thymine, Cytosine and Uracil, are smaller and have a single ring, while the purines, Adenine and Guanine, are larger and…
Correct answer: Uracil, Cytosine and Thymine- A. 2
- B. 4
- C. 6
- D. 8
Explanation: Humans have 2 pairs of chromosomes. So for each pair, there are two options available.
Correct answer: 4- A. Homozygous
- B. X chromosomes
- C. Y chromosomes
- D. Heterozygous
Explanation: Correct option is D. Humans have two sets of chromosomes. Homozygous and heterozygous are terms that are used to describe allele pairs.
Correct answer: Heterozygous