54 problems
1PRACTICE PROBLEMWhat will be the ratio of offspring in a cross between two heterozygous pink flowered plants, if the gene for red flower color (R) is incompletely dominant over the gene for white flower color (r)?
2PRACTICE PROBLEMConsider that brown color (B) in naked mole rats is dominant over white color (b). If a naked brown male mole rat was chosen at random and crossed with a white recessive female, producing all brown offspring, the genotype of that male rat would be:
3PRACTICE PROBLEMWhich of the following type of allele combinations was produced when Mendel conducted the hybridization experiment by crossing one pure tall (TT) and one pure dwarf (tt) pea plant?
4PRACTICE PROBLEMThe advantages of using a pea plant for genetic experiments are all true except one of the following:
5PRACTICE PROBLEMWhen Mendel crossed the two pure-line hom*ozygous plants, the recessive trait did not express itself in theF1 generation. However, the pure hom*ozygous recessive (tt) reappeared in the F2 generation. This demonstrates Mendel's:
6PRACTICE PROBLEMConsider that the allele for a red flower is R (being the dominant allele) and that for a white flower is r. What would be the ratio of the progeny of a heterozygous red-flowered plant crossed with a white-flowered plant?
7PRACTICE PROBLEMTortoiseshell cats are female because the trait is caused by a gene located on the X chromosome. Which of the following Mendel's law best describes the reason why tortoiseshell cats are almost always female?
8PRACTICE PROBLEMWhich of the following statements regarding monohybrid cross is false?
9PRACTICE PROBLEMWhich of the following crosses will result in 100% heterozygous offspring?Cross I P: TT × ttCross II P: Gg × GgCross III P: RR × RRCross IV P: YY × yy
10PRACTICE PROBLEMIn a monohybrid cross between two heterozygous tall plants, what is the expected genotype of the F1 generation?
11PRACTICE PROBLEMWhich of the following offspring results from a cross between a monohybrid round-seeded pea plant and a wrinkled-seeded pea plant?
12PRACTICE PROBLEMFour different types of pea plants are self-fertilized to obtain the following three groups of progeny:Group 1: Round seeded pea plants= 101, wrinkled seeded pea plants= 99Group 2: Round seeded pea plants= 99, wrinkled seeded pea plants= 0Group 3: Round seeded pea plants = 90; wrinkled-seeded pea plants = 30.Identify the group of progeny that is the result of a cross between two heterozygous parents:
13PRACTICE PROBLEMWhat is the primary purpose of doing a test cross?
14PRACTICE PROBLEMThe _______ is defined as the distribution pattern of the physical features in the offspring after a genetic cross is made.
15PRACTICE PROBLEMA total of 700 pea plants with round seeds are allowed to self-fertilize. Out of pea plants, 300 pea plants produced all round-seeded pea plants, whereas 400 pea plants produced both round and wrinkled-seeded progeny in a correct ratio of 3:1. What percentage of parental pea plants is hybrid for roundness?
16PRACTICE PROBLEMIn a monohybrid cross between a pea plant that is hom*ozygous dominant for seed texture (smooth) and a pea plant that is hom*ozygous recessive for seed texture (wrinkled), what is the expected phenotype ratio of the offspring?
17PRACTICE PROBLEMThe following progeny are observed in a cross between two guinea pigs:Black coat = 120 White coat = 97Based on the above data, what is TRUE about the genotype of the parents of the above progeny?
18PRACTICE PROBLEMThe following progeny are observed in a cross between two pea plants:Tall plants= 521Short plants= 523Based on the above data, what is TRUE about the genotype of the parents of the above progeny?
19PRACTICE PROBLEMIn a monohybrid cross between two pea plants with yellow seeds (YY) and green seeds (yy), what is the expected genotype ratio of the offspring in the F2 generation?
20PRACTICE PROBLEMWhich of the following does not follow Mendel's law of independent assortment?
21PRACTICE PROBLEMA self-cross between heterozygous purple-flowered pea plants yields a total of 2100 progeny. What is accurate about the number of purple and white-flowered progeny born as a result of this cross if it strictly follows the Mendel Law?
22PRACTICE PROBLEMIn Mendel's experiment, the F1 generation was produced through _________ while the F2 generation was produced through ________.
23PRACTICE PROBLEMWhat is the probability of having a heterozygous normal bristle shape offspring from a cross between a heterozygous normal bristle shape Drosophila and a hom*ozygous curly bristle shape Drosophila?
24PRACTICE PROBLEMIn pea plants, the allele for green pods (G) is dominant over the allele for yellow pods (g). What is the predicted frequency of green pods from a cross between two bean plants that are heterozygous green pod?
25PRACTICE PROBLEMMendel used the test cross to explore the genotype of the pea plants. In this method, the plant in question will be crossed with a plant that is hom*ozygous recessive for the trait. The parental plant in question is heterozygous if:
26PRACTICE PROBLEMIf the F1 progeny from a true breeding cross (of different phenotypes) is crossed with another hom*ozygous recessive true breeding plant, what is the resulting phenotypic ratio?
27PRACTICE PROBLEMWhen Mendel formed the concept of particulate inheritance from his pea plant experiment, what hypothesis did he use to explain the results he obtained?
28PRACTICE PROBLEMBased on Mendel's experiment, what is/are the resulting genotypes of F2 progeny if we cross true breeding pea plants of different phenotypes?
29PRACTICE PROBLEMBased on the results of the garden pea experiment, Mendel came up with a theory which proposes that each plant carries two particles of heredity from each of the parents. This theory was referred to as:
30PRACTICE PROBLEMWhen Mendel crossed true breeding yellow and green pea plants, what made him conclude that the green variant is the recessive trait?
31PRACTICE PROBLEMWhite-furred rabbits are dominant over brown-furred rabbits. If we cross the true-breeding rabbits with different traits, what is the probability of producing white-furred rabbits?
32PRACTICE PROBLEMIf you cross a red-eyed (Aa) Drosophila and a white-eyed (aa) Drosophila, what is the resulting genotypic ratio of the offspring?
33PRACTICE PROBLEMIf you cross a red-eyed (Aa) Drosophila and a white-eyed (aa) Drosophila and produce a total of 150 offspring, how many of them are hom*ozygous dominant?
34PRACTICE PROBLEMIf you cross a red-eyed (Aa) Drosophila and a white-eyed (aa) Drosophila and produce a total of 150 offspring, how many of them are white-eyed?
35PRACTICE PROBLEMIf a hom*ozygous yellow (YY) pea plant is crossed with hom*ozygous green (yy) pea plant, what is the phenotype of the dominant pea plant in the F2 generation?
36PRACTICE PROBLEMIf a heterozygous parent undergoes self-fertilization, what is the probability of producing hom*ozygous offspring?
37PRACTICE PROBLEMWhich of the following statements about self-fertilization is true?
38PRACTICE PROBLEMIf we cross true-breeding plants, what will be the resulting genotypic ratio of F2 progeny?
39PRACTICE PROBLEMIf we cross true-breeding plants, what will be the resulting phenotypic ratio of F2 progeny?
40PRACTICE PROBLEMTo further investigate inheritance patterns, Mendel crossed true-breeding plants.What does true-breeding mean?
41PRACTICE PROBLEMWhich of the following statements about monohybrid cross is true?
42PRACTICE PROBLEMWhich of the following statements about the true-breeding line is false?
43PRACTICE PROBLEMWhat does it imply if a test cross yields 50% heterozygous and 50% hom*ozygous recessive offspring?
44PRACTICE PROBLEMWhich of the following crosses is considered a monohybrid cross?
45PRACTICE PROBLEMIn guinea pigs, fur color is an autosomal recessive Mendelian trait. A dominant gene "B" in guinea pigs is responsible for making the fur black, whereas a recessive allele "b" makes the fur white. Two guinea pigs were mated to produce the following number of offspring:Guinea pigs with black fur= 9Guinea pigs with white fur=3What is the possible genotype of the parents of this offspring?
46PRACTICE PROBLEMIn pea plants, the height of the plant is a genetic trait that has two distinct phenotypes: tall and short. The allele for tall height is completely dominant over the allele for short height. In a cross between two pea plants that are hybrids for height, we obtained 100 offspring. Which of the following is the correct number of phenotypes among the offspring?
47PRACTICE PROBLEMIn a cross between two pea plants, the following progeny were obtained:1. Plants that have green pods = 9602. Plants that have yellow pods = 315On the basis of the above observations, what is true about the parents of this cross?
48PRACTICE PROBLEMIn pea plants, if the F1 gametes with Dd and Dd genotypes undergo random fertilization and produce 4 offspring, how many of them are heterozygous?
49PRACTICE PROBLEMRed eye color is dominant over white eye color in Drosophila. If we allow a hom*ozygous dominant and a hom*ozygous recessive Drosophila to mate, all their offspring will be:
50PRACTICE PROBLEMRed eye color is dominant over white eye color in Drosophila. Which crosses do not produce a white eye color in the offspring?
51PRACTICE PROBLEMHuntington's disease is a progressive autosomal dominant brain disorder that affects cognition, emotion, and movement, but only after a certain stage in the process of the gene's mutation. A heterozygous man with Huntington's disease is married to a normal woman. Determine the likelihood that their future children will have Huntington's disease.
52PRACTICE PROBLEMTall (A) pea plants are dominant over short (a) pea plants. If a heterozygous pea plant is allowed to self-fertilize, what is the probability of producing tall pea plants?
53PRACTICE PROBLEMTall (A) pea plants are dominant over short (a) pea plants. If a heterozygous pea plant is allowed to self-fertilize, which of the genotypes has a 50% probability of appearing in the F1 generation?
54PRACTICE PROBLEMThe genetic analysis which can be performed by crossing parental generations that differ in a single trait is called _____.
