Primavera Biology B Unit 1: Genetics Questions and Answers 100% Pass

Primavera Biology B Unit 1: Genetics Questions and Answers 100% Pass CHECKPOINT 01 Some people have dimples; other people do not. Having dimples is dominant over not having dimples. If the allele for having dimples is represented with the letter D, what allele combinations can result in having dimples? DD, Dd Which statement is true about model organisms? They help scientists understand biological processes. A pea plant that is tall has a dominant trait. Which statements are true about the genotype/phenotype relationship of the plant? Select all that apply. When the phenotype is tall, the genotype can either be TT or Tt. The genotype Tt always results in a phenotype that is tall. What statement would be true according to the theory of blending inheritance? The offspring of a tall parent plant and a short parent plant will all have a height in the middle. Mendel crossed a tall pea plant with a short pea plant. All the offspring in the first generation were tall pea plants. How did Mendel explain why all the offspring were tall pea plants? Two factors affect the height trait of pea plants. One of the factors is dominant over the other. Read the statement: When Mendel crossed a purple-flowered pea plant with a white-flowered pea plant, the offspring were always X. When Mendel crossed the offspring with each other, the distribution was about Y purple and Z white. The more experiments Mendel did with pea plants, the closer they approached these percentages. Which option correctly replaces X, Y, and Z in the statement? X: purple Y: 75% Z: 25% In some situations, when two purple-flowered pea plants reproduce, the offspring can have purple or white flowers. When this experiment is run repeatedly, it is discovered that three-fourths of the offspring have purple flowers and one-fourth of the offspring have white flowers. What would happen if this experiment were run only once? The experiment would result in a plant with either purple or white flowers. The conclusion would depend on this single result and would not be accurate. Which term defines a genotype composed of two identical alleles? homozygous What statement is true about heterozygous organisms? Heterozygous organisms are more genetically diverse than homozygous organisms. CHECKPOINT 02 Which statement best describes a monohybrid cross? a cross in which the traits of a single characteristic are studied Twenty-five percent of the possible offspring for a cross are homozygous dominant. What genotype do each of the parents have? heterozygous In pea plants, green seeds are dominant (Y), and yellow seeds are recessive (y). The following Punnett square shows a cross for seed color. What is the probability that the offspring will have green seeds? 100 percent In the Punnett square, tall is dominant (T), and short is recessive (t). What is the ratio of tall offspring to short offspring? 3:1 What valuable information was gained from Mendel's dihybrid crosses? Select all that apply. Statistical and probability methods can be used to determine how likely an offspring is to inherit certain traits. Inheritance of one trait does not affect inheritance of another. Dihybrid cross experiments led Mendel to propose his law of independent assortment. Which statement best describes this law? The law of independent assortment states that alleles of different genes are inherited independently of each other. Read the following statement. A dihybrid cross experiment is carried out in pea plants. The traits being observed are flower color and stem length. In the F2 generation, 81 plants have purple flowers and long stems, 27 plants have purple flowers and short stems, 27 plants have white flowers and long stems, and 3 plants have white flowers and short stems. Which traits are recessive? white flowers, short stem A dihybrid cross experiment is carried out in pea plants. Which statements are true? Select all that apply. The F1 generation will all have both dominant phenotypes. The F2 generation will be a mixture of four different phenotypes. CHECKPOINT 03 Which of the following facts was unknown to Gregor Mendel? alleles for genes are found on chromosomes Why are linked traits inconsistent with Mendel's laws? Linked traits are likely to be inherited together. This is not consistent with Mendel's law of independent assortment. What is an effect that results when two genes are located side by side on the same chromosome? Punnett squares can give incorrect predictions of inheritance. What statement is true? A diploid organism most often has two alleles for a trait. What is epistasis? traits where one gene interferes with the effect of another What is an example of an environmental effect on phenotype? the gender of sea turtles being affected by the temperature How many alleles are typically found for mitochondrial genes? 1 Which of these are genes that have more than two alleles? the C gene for melanin production in rabbit coats Multiple alleles for a gene make populations more diverse. What are the benefits of this? Select all that apply. If a population encounters a new disease, some of the individuals may be immune to it. It makes it more likely that a population will survive environmental changes. CHECKPOINT 04 What are characteristics of polygenic traits? Select all that apply. On a histogram, traits distribute on a bell-shaped curve. Traits are continuous across a range. Which factor determines if someone has brown eyes or green eyes? several genes acting together A few genes are responsible for melanin pigmentation in human skin. Which of the following are true? Select all that apply. The combination of alleles determines how pigmented the skin will be. Each allele only contributes a small amount to the phenotype. How can epistatic interactions affect the number of phenotypes that can appear? Select all that apply. Epistasis can create new phenotypes. Epistasis can modify existing phenotypes. Epistasis can mask genes and prevent them from affecting the phenotypes. What is the difference between blood types in the ABO blood type system? antigens on red blood cells Two people have the genotype I^AI^B. Of the following options, what possible genotypes could their children have? I^AI^B I^BI^B I^AI^A A person has blood type B. What combination of alleles could she have to give her this blood type? Select all that apply. I^Bi I^BI^B Two parents both have homozygous genotypes. One parent has blood type A and the other has blood type B. What genotype can be expected in all of their children? AB Blood type is an example of which of the following? Select all that apply. a situation in which more than one allele for a trait is dominant a situation in which a gene has three or more alleles CHECKPOINT 05 Which are sex-linked traits? Select all that apply. red-green color blindness Duchenne muscular dystrophy A female has a brother who is color blind and a mother who is not. What is the probability that the female is a carrier for the trait? 50% Which statements about the inheritance of color blindness are true? Select all that apply. Females can inherit the color blindness allele from their fathers. Males are more likely to be color blind than females. Fathers can only pass X-linked traits to their _[blank1]_, while mothers can pass X- linked traits to their _[blank2]_. What option correctly completes this sentence. daughters; sons and daughters Which of these statements about mutation are true? Select all that apply. A mutation can be inherited from a parent's genetic material. A mutation can occur when DNA replicates during cell division. A mutation changes the DNA found in a cell. Which of these diseases are examples of autosomal recessive human genetic disorders? Select all that apply. sickle cell anemia Tay-Sachs disease cystic fibrosis If both parents are unaffected carriers of an autosomal recessive disorder, which one of the following statements is true? The offspring will have a 25% chance of having the disorder. How is inbreeding related to the expression of human genetic disorders? Inbreeding increases the chances that a human genetic disorder will be expressed by the offspring. A mutated CFTR gene codes for an abnormal CFTR protein. This protein alters the normal function of the cell, leading to the disorder cystic fibrosis. Based on the statements, which of the following is true? Cystic fibrosis is caused by a mutated CFTR gene.