#1
Which process involves the division of a single cell into two daughter cells?
Mitosis
ExplanationCell division resulting in identical daughter cells.
#2
In humans, how many chromosomes are present in a diploid cell?
46
ExplanationTotal number of chromosomes in human somatic cells.
#3
During which phase of the cell cycle does DNA replication occur?
S phase
ExplanationPeriod when DNA synthesis takes place in preparation for cell division.
#4
What is the term for a gene that masks the effect of another allele?
Dominant
ExplanationTrait expressed when present, masking the recessive allele.
#5
What is the term for a cell that contains two sets of chromosomes?
Diploid
ExplanationCell with paired chromosomes, one from each parent.
#6
In genetics, what does the term 'heterozygous' mean?
Having two different alleles for a particular gene
ExplanationPossessing two distinct alleles for a given gene locus.
#7
Which phase of mitosis involves the separation of sister chromatids?
Anaphase
ExplanationStage when sister chromatids are pulled apart.
#8
What is the term for a change in the nucleotide sequence of DNA?
Mutation
ExplanationAlteration in the genetic material.
#9
Which type of cell division results in the formation of gametes?
Meiosis
ExplanationProcess yielding haploid gametes.
#10
What is the term for an organism that has two different alleles for a particular gene?
Heterozygous
ExplanationIndividual with dissimilar alleles for a given gene.
#11
What is the term for the exchange of genetic material between homologous chromosomes during meiosis?
Crossing over
ExplanationGenetic recombination between homologous chromosomes.
#12
Which organelle is responsible for the production of ribosomes?
Nucleolus
ExplanationSite of ribosome synthesis within the nucleus.
#13
What is the term for a specific form of a gene?
Allele
ExplanationVariant of a gene responsible for a particular trait.
#14
Which enzyme is responsible for unwinding the DNA double helix during replication?
Helicase
ExplanationEnzyme that catalyzes the separation of DNA strands.
#15
Which type of RNA carries amino acids to the ribosome during protein synthesis?
tRNA
ExplanationRNA molecule responsible for delivering amino acids.
#16
What is the term for the physical expression of a genetic trait?
Phenotype
ExplanationObservable characteristic resulting from genotype.
#17
What is the term for the genetic makeup of an organism?
Genotype
ExplanationCollection of an organism's genes.
#18
Which process involves the synthesis of mRNA from a DNA template?
Transcription
ExplanationConversion of DNA information into mRNA.
#19
What is the term for the fusion of gametes from two different individuals?
Fertilization
ExplanationUnion of male and female gametes.
#20
Which of the following structures is not found in a prokaryotic cell?
Nucleus
ExplanationAbsence of a membrane-bound nucleus in prokaryotes.
#21
Which of the following genetic disorders is caused by the presence of an additional chromosome 21?
Down syndrome
ExplanationTrisomy of chromosome 21 leading to developmental disabilities.
#22
In a Punnett square, what do the letters represent in the boxes?
Offspring
ExplanationPossible genetic combinations resulting from a cross.
#23
Which of the following is a sex-linked genetic disorder?
Hemophilia
ExplanationGenetic disorder associated with the X chromosome.
#24
Which of the following genetic disorders results from a defect in the CFTR gene?
Cystic fibrosis
ExplanationCondition caused by mutations in the CFTR gene.
#25
Which of the following genetic disorders is characterized by an abnormality in the X chromosome, leading to underdeveloped secondary sexual characteristics in males?
Androgen insensitivity syndrome
ExplanationCondition where cells don't respond to androgens due to X chromosome mutations.