Genetics Quiz
Questions: 16 · 10 minutes
1. Which pair of processes creates new allele combinations during meiosis?
Replication and cytokinesis alone
DNA transcription and translation
Binary fission and budding
Crossing over and independent assortment
2. A typical human body cell contains 46 chromosomes. How many chromosomes does a typical human egg or sperm contain?
23
46
92
44
3. What is a gene?
A complete set of chromosomes in an organism
A protein that copies an entire chromosome
A visible characteristic produced only by the environment
A segment of DNA that contributes to a functional product or trait
4. During gene expression, what is the primary role of messenger RNA, or mRNA?
It permanently stores the organism's entire genome
It joins homologous chromosomes during meiosis
It carries a copied genetic message from DNA for use by a ribosome
It transports amino acids directly to offspring
5. One parent has ABO blood genotype Iᴬi, and the other has genotype Iᴮi. What is the probability that their child will have genotype ii and type O blood?
25%
50%
75%
0%
6. Compared with mitosis, what is a typical result of meiosis beginning with one diploid cell?
Two genetically identical diploid cells
Four haploid products with genetic variation
One diploid cell with twice as much DNA
Two haploid products that are always genetically identical
7. A plant has genotype Bb and produces blue blossoms. Which detail is the plant's phenotype?
The genotype Bb
The allele B
Its blue blossoms
Its pair of homologous chromosomes
8. In a simple Mendelian trait, what does it mean for allele A to be dominant over allele a?
The A-associated phenotype appears in an Aa heterozygote
Allele A prevents allele a from being inherited
Allele A is necessarily healthier than allele a
Allele A is always more common in the population
9. In a simple dominant-recessive model, two heterozygous parents are crossed: Aa × Aa. What is the probability that an offspring will have genotype aa?
0%
25%
50%
75%
10. Which description represents a homozygous genotype at a gene locus?
A single B allele with no second allele specified
One dominant allele and one recessive allele
Two copies of the same dominant allele
Two different alleles located at the same locus
11. In a simple pedigree, two unaffected parents have an affected child of either sex. Which inheritance pattern is most consistent with this observation?
Autosomal dominant with complete penetrance
Autosomal recessive inheritance
Y-linked inheritance
Mitochondrial inheritance affecting every child
12. Genetically identical seedlings are grown under different light conditions and develop different average heights. What does this observation best support?
Genetically identical organisms must always have identical phenotypes
Light changes every allele into a dominant allele
Environmental conditions can influence phenotype
Height cannot have any genetic contribution
13. One DNA strand has the sequence 5′-ATGC-3′. What is the complementary antiparallel sequence?
3′-ATGC-5′
3′-UACG-5′
5′-TACG-3′
3′-TACG-5′
14. A homozygous dominant plant, TT, is crossed with a homozygous recessive plant, tt. What genotype will their offspring have?
Every offspring will inherit one T allele and one t allele
Half will inherit two dominant alleles and half will inherit two recessive alleles
Every offspring will inherit two dominant alleles
The offspring will occur in a 1:2:1 genotype ratio
15. For an autosomal recessive condition, one parent is a carrier, Aa, and the other has genotype aa. What is the probability that an offspring will have genotype aa?
25%
100%
75%
50%
16. A mutation occurs in one of an adult's skin cells. What would generally be required for that mutation to be inherited directly by a child?
The altered skin cell would need to divide by mitosis
The mutation would also need to be present in the lineage producing an egg or sperm
The altered DNA would need to spread to every body cell
The mutation would need to change the person's visible appearance