Mendelian Inheritance
A red flowering plant (Rr) self-pollinates. What percentage of the offspring will have white flowers?
25%
In four o’clock flowers, red (RR) and white (WW) parents produce pink (RW) offspring. What type of inheritance is this?
Incomplete dominance
During which phase of meiosis does crossing-over occur?
Prophase I
A hydrangea changes color based on soil pH. What is affecting this phenotype?
x2 points
Environmental conditions
Albinism is a recessive condition in humans (aa). A man and woman are both carriers (heterozygous, Aa). What is the chance that their child will be albino?
25%
Which of the following traits is most likely controlled by polygenic inheritance?
A. Freckles
B. Eye color
C. Blood type
D. Widow’s peak
B. Eye color
Which of the following can occur if chromosomes fail to separate properly during meiosis (nondisjunction)?
A. No effect on the offspring
B. A genetic disorder, such as Down syndrome
C. A complete loss of all chromosomes
D. A change from diploid to haploid cells
B. A genetic disorder, such as Down syndrome
Farmers use genetically modified (GMO) crops to increase resistance to pests and improve yield. What process is used to directly insert a beneficial gene into a plant’s DNA?
A. Selective breeding
B. Cloning
C. Genetic engineering
D. Meiosis
C. Genetic engineering
In humans, having a widow’s peak (W) is dominant over a straight hairline (w). A heterozygous parent and a homozygous recessive parent have a child. What is the probability that the child has a widow’s peak?
50%
A mother has blood type A and a father has blood type B. Their child has blood type AB. What type of inheritance pattern does this follow?
Codominance
Which of the following explains why siblings (except for identical twins) do not look exactly alike?
A. Chromosomes separate randomly during meiosis (independent assortment)
B. All traits are inherited as dominant or recessive
C. Every sperm cell carries the exact same genes
D. Only maternal genes determine appearance
A. Chromosomes separate randomly during meiosis (independent assortment)
A farmer successfully clones a prize-winning cow. What can be expected of the cloned cow?
A. It will be genetically identical to the original cow
B. It will have a mix of genes from both parent cows
C. It will look the same but have different DNA
D. It will have completely random genetic traits
A. It will be genetically identical to the original cow
In pea plants, round seeds (R) are dominant to wrinkled seeds (r), and yellow seeds (Y) are dominant to green seeds (y). If two heterozygous plants (RrYy × RrYy) are crossed, what is the probability of getting a wrinkled, green-seeded plant (rryy)?
x2 points
1/16
Himalayan rabbits have fur that changes color depending on temperature. Their ears, nose, feet, and tail turn black in colder temperatures. What best explains this phenomenon?
The gene for fur color is influenced by environmental factors
A normal human somatic (body) cell contains 46 chromosomes. After meiosis, how many chromosomes are in a human gamete (sperm or egg)?
A. 92
B. 46
C. 23
D. 12
C. 23
UV radiation can cause mutations in skin cells, sometimes leading to cancer. Why is this type of mutation not passed on to offspring?
A. Mutations in skin cells do not affect the DNA of gametes (sperm or egg)
B. Cancer cells prevent DNA from being inherited
C. Mutations can only be inherited if they happen in childhood
D. Skin cancer mutations change all of a person’s DNA, so they are eliminated
A. Mutations in skin cells do not affect the DNA of gametes (sperm or egg)
A pea plant with purple flowers (dominant) is crossed with a white-flowered plant (recessive). The offspring are half purple and half white. What were the genotypes of the parent plants?
A. PP × pp
B. Pp × Pp
C. Pp × pp
D. PP × Pp
C
In snapdragons, flower color follows an incomplete dominance pattern. A red-flowered plant (RR) is crossed with a white-flowered plant (WW), producing pink (RW) flowers. If two pink-flowered plants are crossed, what percentage of the offspring will also be pink?
50%
What is the main purpose of crossing over during meiosis?
x2 points
To increase genetic variation
A gardener notices that her hydrangea plants bloom blue in one part of her yard and pink in another. What is the most likely explanation?
A. The plants have different genotypes
B. Hydrangea color is controlled by soil pH and aluminum levels
C. The flowers are undergoing incomplete dominance
D. The plants experience crossing-over
B. Hydrangea color is controlled by soil pH and aluminum levels