Height in humans generally shows a normal (bell-shaped) distribution. What type of inheritance most likely determines height?
which of the following is an example of inheritance?
In his breeding experiments, Mendel first crossed true-breeding plants to produce a second generation, which were then allowed to self-pollinate to generate the offspring. How do we name these three generations?
Consider pea plants with the genotypes GgTt and ggtt . These plants can each produce how many type(s) of gametes?
Two plants are crossed, resulting in offspring with a 3:1 ratio for a particular trait. What does this suggest?
Which of the following is true about a plant with the genotype AABbcc?
Geneticists analyze pedigrees to follow the inheritance of genetically controlled conditions. Three things must be determined in a pedigree analysis:
Which of the following do you expect if an individual is heterozygous for the sickle-cell trait?
What is an allele?
What do we mean when we use the terms monohybrid cross and dihybrid cross?
You cross a true-breeding red-flowered snapdragon with a true-breeding white-flowered one. All of the F1 are pink. What does this say about the parental traits?
Various procedures can be used to detect genetic disorders before birth. Among the tests discussed in this chapter, which is the least invasive (list first), and which two allow the chromosomes of the fetus to be examined?
Black eyes are dominant to orange eyes, and green skin is dominant to white skin. Sam, a MendAlien with black eyes and green skin, has a parent with orange eyes and white skin. Carole is a MendAlien with orange eyes and white skin. If Sam and Carole were to mate, the predicted phenotypic ratio of their offspring would be _____.
In order to determine the genotype of a MendAlien with black eyes and green skin, you would cross this individual with a(n) _____ individual.
A cross between an individual with orange eyes and green skin and an individual with black eyes and white skin is an example of a _____ cross.
A phenotypic ratio of 9:3:3:1 in the offspring of a cross indicates that _____.
An individual heterozygous for eye color, skin color, and number of eyes mates with an individual who is homozygous recessive for all three characters; what would be the expected phenotypic ratio of their offspring? Hint: B = black eyes, b = orange eyes; G = green skin, g = white skin; C = two eyes, c = one eye
A BbGg x bbgg cross yields a phenotypic ratio of approximately 5 black eyes, green skin : 5 orange eyes, white skin : 1 black eyes, white skin : 1 orange eyes, green skin. Which of the following best explains these results?
In the following cross the genotype of the female parent is BbGg. What is the genotype of the male parent? Hint: B = black eyes, b = orange eyes, G = green skin, g = white skin
In a situation in which genes assort independently, what is the ratio of the gametes produced by an AaBB individual?
How could the botanist best determine whether the genotype of the green-pod plant is homozygous or heterozygous?
Suppose that the botanist carried out the test cross described in Parts A and B and determined that the original green-pod plant was heterozygous (Gg). Which of Mendel’s findings does her test cross illustrate?
Law of segregation
Folk singer Woody Guthrie died of Huntington’s disease, an autosomal dominant disorder. Which statement below must be true?
What is the difference between heterozygous and homozygous individuals?
When constructing a Punnett square, the symbols on the outside of the boxes represent _______, while those inside the boxes represent _______.
True or false? The same phenotype can be produced by more than one genotype.
True or false? In diploid organisms, a dominant phenotype will only be expressed if the individual is homozygous dominant for that trait.
If an organism with the genotype AaBb produces gametes, what proportion of the gametes would be Bb?
Two mice are heterozygous for albinism (Aa) . The dominant allele (A) codes for normal pigmentation, and the recessive allele (a) codes for no pigmentation. What percentage of their offspring would have an albino phenotype?
A tall, purple-flowered pea plant (TtPp) is allowed to self-pollinate. (The recessive alleles code for short plants and white flowers.) The phenotypic ratio of the resulting offspring is 9:3:3:1. What is the genotype of the plant whose phenotype appeared once out of every 16 offspring (the “1” in the 9:3:3:1 ratio)?
What process is responsible for the independent assortment of alleles?
How do cells acquire homologous chromosome pairs that carry the alleles that are independently assorted?
Which of the following statements most accurately describes the process of independent assortment?
True or false? The principle of independent assortment is best illustrated by events that take place during metaphase II, during which sister chromatids segregate independently of each other.
How many genetically unique types of gametes could be produced by an individual with the genotype RrYY?
Which of the following parental genotypes would yield a 1:1:1:1 phenotypic ratio in the offspring?
Cystic fibrosis affects the lungs, the pancreas, the digestive system, and other organs, resulting in symptoms ranging from breathing difficulties to recurrent infections. Which of the following terms best describes this?