#1
Which of the following is NOT a component of a chromosome?
Codon
ExplanationCodons are sequences within mRNA, not components of chromosomes.
#2
What is the primary function of telomeres in a chromosome?
To prevent degradation of genetic material at the ends of chromosomes
ExplanationTelomeres act as protective caps, preventing degradation and maintaining chromosome stability.
#3
Which of the following describes the primary structure of a chromosome?
The visible appearance of the chromosome under a microscope
ExplanationThe primary structure refers to the physical appearance of chromosomes when observed under a microscope.
#4
What is the term for the exchange of genetic material between homologous chromosomes?
Recombination
ExplanationRecombination results in genetic diversity by exchanging segments between homologous chromosomes.
#5
Which of the following is true regarding the number of chromosomes in a haploid cell?
It is half the number of chromosomes in a diploid cell
ExplanationHaploid cells contain half the chromosome number of diploid cells, resulting from meiosis.
#6
What is the term for a change in the structure or number of chromosomes in an organism?
Mutation
ExplanationMutations refer to alterations in chromosome structure or number, leading to genetic variation.
#7
Which protein complexes are responsible for the packaging of DNA into chromatin?
Histones
ExplanationHistones bind to DNA, facilitating its compaction into chromatin structures.
#8
What is the term for the specific region of a chromosome where spindle fibers attach during cell division?
Kinetochore
ExplanationKinetochore serves as the attachment point for spindle fibers, ensuring proper chromosome segregation.
#9
Which type of chromatin is transcriptionally active and less condensed?
Euchromatin
ExplanationEuchromatin allows for gene expression as it is less condensed and accessible to transcriptional machinery.
#10
During mitosis, in which phase do chromosomes line up along the metaphase plate?
Metaphase
ExplanationMetaphase is the stage where chromosomes align at the metaphase plate, ready for segregation.
#11
Which of the following processes contributes to genetic diversity by producing non-identical daughter cells?
Meiosis I
ExplanationMeiosis I generates genetic diversity through recombination and independent assortment.
#12
What is the term for the failure of homologous chromosomes or sister chromatids to separate properly during cell division?
Nondisjunction
ExplanationNondisjunction leads to abnormal chromosome numbers in daughter cells, causing genetic disorders.
#13
In eukaryotic cells, during which phase of the cell cycle do chromosomes replicate?
S phase
ExplanationDuring S phase, DNA replication occurs, resulting in the duplication of chromosomes.
#14
What is the term for a specific region of DNA that codes for a particular protein or RNA molecule?
Gene
ExplanationGenes are DNA segments that contain instructions for protein or RNA synthesis.
#15
Which of the following chromosomal abnormalities results in an individual having an extra copy of chromosome 21?
Down syndrome
ExplanationDown syndrome is caused by trisomy 21, leading to intellectual disability and distinct physical features.
#16
Which of the following genetic disorders is caused by a deletion in a portion of chromosome 5?
Cri du chat syndrome
ExplanationCri du chat syndrome results from a deletion on chromosome 5, leading to distinctive cries and developmental delays.
#17
What is the term for the physical expression of an organism's genetic makeup?
Phenotype
ExplanationPhenotype refers to the observable characteristics of an organism resulting from its genetic makeup and environmental influences.