Heredity Quiz
Questions: 16 · 10 minutes
1. Which statement correctly describes the relationship among genes, DNA, and chromosomes?
A gene is a segment of DNA located on a chromosome
DNA is produced by combining several unrelated chromosomes
A chromosome is a short protein segment located inside a gene
An allele is made from a complete set of chromosomes
2. A mutation occurs in one of a person's skin cells. Why is that mutation generally not passed to the person's children through ordinary reproduction?
Only dominant mutations can be inherited
The mutation is not present in the sperm or egg cells that contribute DNA to offspring
Every mutation in a body cell is repaired before reproduction
Body-cell mutations can be inherited only through fathers
3. Which term refers to an organism's combination of alleles for a particular gene?
Acquired characteristic
Phenotype
Genotype
Environmental influence
4. In a flower species showing incomplete dominance, RR plants are red, WW plants are white, and RW plants are pink. Which phenotypes can result from crossing a pink plant with a white plant?
Red only
Pink only
Red and white, but not pink
Pink and white
5. If a homozygous dominant parent with genotype AA is crossed with a homozygous recessive parent with genotype aa, what genotype will all offspring have under simple Mendelian inheritance?
Homozygous dominant, with two dominant alleles
Heterozygous, with one dominant and one recessive allele
Homozygous recessive, with two recessive alleles
A mixture of homozygous dominant and homozygous recessive genotypes
6. A condition is known to be autosomal recessive, and affected individuals have genotype aa. Two unaffected parents have an affected child. Under a simple complete-penetrance model, what is the best conclusion?
At least one parent must be affected by the condition
Both parents must lack the recessive allele
The condition must actually follow dominant inheritance
Both parents are most likely heterozygous carriers
7. For a trait with complete dominance, D produces the dominant phenotype and d is recessive. What is the probability that a Dd × dd cross produces offspring with the dominant phenotype?
50%
25%
75%
100%
8. What does heredity describe?
Changes an organism acquires solely through practice during its lifetime
The transmission of genetic traits from parents to offspring
The classification of organisms according to their habitats
The process by which cells obtain energy from nutrients
9. An organism with a dominant phenotype is crossed with a homozygous recessive organism. Some offspring show the recessive phenotype. What must the dominant-phenotype parent's genotype be?
Homozygous dominant, carrying two dominant alleles
Homozygous recessive, carrying no dominant allele
Heterozygous, carrying one dominant and one recessive allele
Either of the two homozygous genotypes
10. One parent has ABO blood-group genotype Iᴬi and the other has genotype Iᴮi. Which possible child genotype would produce type O blood?
One A allele paired with one B allele
One B allele paired with one recessive i allele
One A allele paired with one recessive i allele
Two recessive i alleles
11. A genetic cross gives each child a 1-in-4 probability of inheriting a particular genotype. The first child does not inherit it. Assuming independent inheritance, what is the probability that the second child will inherit it?
1 in 4
1 in 2
3 in 4
Zero, because the first child did not inherit it
12. Under the standard model of mitochondrial inheritance, a father carries a mitochondrial DNA variant and the mother does not. What transmission pattern is expected for their children?
All children inherit the variant
Only the sons inherit the variant
Only the daughters inherit the variant
None of the children typically inherit the variant from their father
13. In genetics, what is an allele?
The visible expression of every trait in an organism
The complete collection of genetic material in a cell
An alternative version of a gene
The cellular process that separates homologous chromosomes
14. Identical twins have nearly the same inherited DNA but develop somewhat different heights after growing up with different nutrition. What does this best illustrate?
Each twin must have inherited a completely different height gene
Environmental conditions can influence how inherited potential appears in the phenotype
Nutrition permanently changes every allele in every cell
Inherited traits are unaffected by environmental conditions
15. A species has 12 chromosomes in each diploid body cell. How many chromosomes should a normal gamete contain after meiosis?
3
12
6
24
16. In a typical human body cell, where do the two chromosomes in a homologous pair usually come from?
One comes from each biological parent
Both come from the biological father
Both come from the biological mother
They are formed only after the cell begins dividing