1D Genetics
Hemophilia is an X-linked recessive disorder (Xh) that is passed through generations and can be traced by using a pedigree. What is the probability that a female child of Charles and Marie would suffer from hemophilia?
0 percent
The allele for curly hair is incompletely dominant. If a mother is homozygous for curly hair and the father is homozygous for straight hair, what percentage of the offspring will exhibit characteristics of both parents?
100 percent
Punnett squares are used to show possible combinations of alleles or to predict the probability of a trait occurring in offspring. Cats that have coats that are a patchwork of black and orange are called tortoiseshell cats, are typically female, and have genes that code for both black fur (Xo) and orange fur (XO) located on the X chromosomes. Y chromosomes do not code for color in tortoiseshell cats. A female cat that has only orange fur (XOXO) is crossed with a male cat that has only black fur (XoY). How many of the offspring will exhibit tortoiseshell coloring?
2 in 4
A plant can produce either purple flowers or white flowers. What is the probability of purple-flowered offspring if two plants that are heterozygous for purple flowers are crossed?
3:4
A pea plant that has round seeds has the genotype Rr. It is crossed with a pea plant that has wrinkled seeds and the genotype rr. What is the probability that the offspring will have wrinkled seeds?
50 percent
Hemophilia is an X-linked recessive disorder. What is the probability of having hemophilia for the cross that is shown in the Punnett square?
50 percent
In pea plants, tallness (T) is dominant to shortness (t). What is the predicted genotypic ratio of the offspring if a homozygous short plant is crossed with a heterozygous tall plant?
50 percent Tt, 50 percent tt
Why is it important to know a person's rhesus factor before a blood transfusion?
A patient who is Rh- can receive only Rh- blood.
The flowchart below shows the three generations of a cross between a pea plant that has yellow pods and a pea plant that has green pods. Green pods are the dominant trait. The flowchart is missing the labels that describe the traits.
A, C, and D
Which pedigree symbol is used to represent a female carrier of a recessive X-linked trait?
Circle with one side white, other side purple
Which statement summarizes the law of segregation?
Gametes carry one allele for each trait.
What was Thomas Hunt Morgan's main contribution to science?
He discovered that certain traits were linked to the X chromosome.
What can be known about Mendel's five-part hypothesis?
It is an answer to a scientific question and is based mostly on research.
Tall pea plants are dominant over short pea plants. If there are 200 short plants in the F2 generation from a cross that followed Mendel's methods, about how many plants will be tall in that generation?
NOT 200
The Punnett square predicts the ratio of genotypes in the offspring, based on the genotypes of the parents. The Punnett square below examines the chance of offspring having freckles, which is a dominant trait. Based on the Punnett square, what is the probability that the offspring will have freckles?
NOT 25 percent
When Mendel crossed purebred purple flowering plants (PP) with purebred white flowering plants (pp), what were the flower colors of the resulting offspring?
NOT 50 percent white and 50 percent purple
Drosophila eye color is an X-linked trait. Red eye color is dominant, and white eye color is recessive. Which Punnett square shows the probability that 100 percent of offspring will have red eyes?
NOT D
If a red cow (homozygous dominant) is crossed with a white cow (homozygous dominant), what alleles will the offspring have?
NOT Rw
Some people have freckles, and some people do not have freckles. If a child has freckles, at least one parent has freckles. However, the child may have a sibling that does not have freckles. Which statement best describes the presence of freckles?
NOT There is no dominant allele for freckles.
Which statement best describes an understanding of genetics that would be missing without the work of Mendel?
Some alleles are dominant, and some alleles are recessive.
Which statement best describes the potential confusion in early studies of inheritance patterns for skin color?
The polygenic trait appeared as incomplete dominance.
Why did Gregor Mendel choose to use purebred plants in his experiments?
They exhibit only one form of a trait.
Scientists often use fruit flies as a method to test hypotheses about human genes. Why are fruit flies advantageous in the study of human inheritance?
They reproduce quickly and take up little space.
Why did Mendel study pea plants?
They reproduce sexually and have many traits that are easy to observe.
Why did Gregor Mendel study pea plants?
They reproduce sexually.
Which is the best example of a hypothesis leading to new experimental methods?
Thomas Hunt Morgan continued the genetic research of Gregor Mendel, but Morgan used fruit flies.
There are two different alleles for flower color, P and p. The image shows a white sweet pea that is labeled with its two alleles for petal color. What can you surmise from the labeled image?
White petal color is a recessive trait.
Which allele combination represents a female who has a heterozygous sex-linked trait?
XRXr
Which allele combination represents a female who is a carrier for an X-linked recessive disorder?
XRXr
What is genotype for a recessive trait found on the female chromosome?
Xh
The concept of evolution by way of natural selection is a central tenet in biology that has been tested in numerous ways by many scientists but is not yet considered a law. Evolution by way of natural selection is most likely which type of concept?
a hypothesis that can be accepted as true based on repeated experimentation with similar results
Which statement best describes human eye color?
a polygenic trait that follows non-Mendelian inheritance patterns
What is a gene?
a segment of DNA that is the basic unit of heredity
Which was not a result of the 1898 discovery of the four blood types?
all blood types made compatible with each other
Nucleic acids offer variability because they contain alternate forms of genes called
alleles
A scientist wants to examine a genetic disease in humans. The scientist hypothesizes that the disease can be treated by using gene therapy. Humans take a long time to reproduce and develop, so the scientist will have to
develop new methods to test the hypothesis.
Hemophilia is an X-linked recessive disorder (Xh) that is passed through generations and can be traced by using a pedigree. Based on the pedigree that is shown, which describes John?
does not have hemophilia
A purebred purple flowering plant is crossed with a purebred white flowering plant, and they produce offspring that have purple flowers. Which is the trait for purple flowers?
dominant
Which describes the notation Tt for the trait of being tall?
heterozygous genotype
Which term describes an organism that has identical alleles for a trait?
homozygous
There are two different alleles for flower color, P and p. The image shows a purple sweet pea that is labeled with its two alleles for petal color. Which is the genotype of the sweet pea?
homozygous dominant
Which type of scientific statement is defined as "a possible explanation or answer to a scientific question that is based on prior knowledge or research and is testable"?
hypothesis
Which inheritance pattern results when parents are crossed for pure traits and the resulting offspring have traits that appear to blend?
incomplete dominance
Which of Mendel's laws or principles states that gametes carry one allele for each trait?
law of segregation
Which describes the mating of organisms that have different homozygous alleles for a single trait?
monohybrid cross
What controls traits and inheritance?
nucleic acids
Which has the most control of traits and inheritance?
nucleic acids
Which type of traits vary quantitatively due to the interaction of multiple genes?
polygenic
Skin color, fur color, and height are examples of which inheritance pattern?
polygenic inheritance
Which of Mendel's laws or principles explains that traits are passed from parents to offspring individually instead of as pairs, groups, or sets?
the law of independent assortment
