Principles of Inheritance & Variation (Genetics) Questions and Answers

In rock roses, flowers come in three shades of pink: coral, salmon, and burgundy. If a pure-breeding coral plant is crossed with a pure-breeding burgundy plant, all the offspring are salmon. Which of the following is probably true? The heterozygote plants' flower color is burgundy. Plants with salmon flowers have an advantage over coral and burgundy flowers. These roses have three alleles controlling flower color. The heterozygote plants' flower color is salmon. The heterozygote plants' flower color is coral.

When considering recessive alleles, these alleles are most commonly explained by: a sequence change that makes a poisonous protein a sequence change that causes a gain-of-function mutation a sequence change that causes a loss-of-function mutation a sequence change that expresses a protein with redundant function

You are given two true-breeding groups of gerbils. The gerbils in the first group have black fur and curly tails; the gerbils in the second group have yellow fur and straight tails. When you produce an F1 generation, you see only gerbils with black fur and curly tails. When you produce an F2 generation, you see that 75% of the gerbils have black fur and 25% have yellow fur. You also see that 25% of the gerbils have straight tails and 75% have curly tails. If the single alleles responsible for coat color and tall appearance sort independently, how many of the black gerbils in this generation are expected to have straight tails? 25% 0% 75% 100%

A recessive disease shows incomplete penetrance such that only 50% of individuals that are homozygous recessive actually express the disease. If two heterozygous individuals have two children, what is the probability that neither of the children have the disease? A) 1/8 B) 27/64 C) 1/16 D) 49/64

A gardener is crossing flowers displaying complete dominance for flower color. The purple (P) trait is dominant and the white trait is recessive (p) The gardener performs hybridization with two pure-bred individuals (Purple x White) to create F1 offspring What is the genotype of the F1 flowers? Purple PP White Pp pp

In the garden pea, yellow cotyledon color is dominant to green, and inflated pod shape is dominant to the constricted form. A homozygous dominant yellow inflated plant is crossed with a homozygous recessive green constricted plant. All of the F1 generation were yellow and inflated. The following are the results for the F2 generation in which 994 peas were counted. 193 green, inflated 184 yellow constricted 556 yellow, inflated 61 green, constricted Do the results agree with classical Mendelian genetics? Make a hypothesis, and support your answer using Chi-square analysis.

Huntington's disease arises from a single mutation in a gene. The Huntington's mutation is dominant (A). Sickle Cell Anemia arises from a single mutation in a gene as well. The Sickle Cell mutation is recessive (a). If an individual has the heterozygous genotype (Aa), which of the following diseases would be present or "show up"? Huntington's Sickle Cell

Sickle Cell Anemia arises from a single mutation in a gene. The Sickle Cell mutation is recessive (a). Which of the following individual genotypes would have Sickle Cell Anemia? aa ABA AA Aa

In tracking the white gene in Drosophila that was discussed in class, a true-breeding white-eyed female fly is crossed to a red-eyed male fly. If a single nondisjunction event of the sex-chromosomes occurs in meiosis I in this red-eyed male fly, what is the genotype and phenotype of an exceptional progeny (one with an abnormal number of sex-chromosomes) that could result from this nondisjunction event? (O = no sex chromosome) A) X^w/X^w/Y white-eyed female B) X^w/X^w+/Y red-eyed female C) X^w/O white-eyed female D) X^w+/O red-eyed male E) X^w+/Y red-eyed male

Certain genetic diseases are associated with particular populations because among major factors in establishing high frequencies of particular alleles in specific populations include inbreeding in small populations the preference for consanguineous matings in many societies the founder principle operating in small migrant populations all of the above

Cross a homozygous tasting and unattached earlobe parent with a homozygous non-tasting attached earlobe parent. What is/are the possible genotype(s) of the offspring? TTFF and ttff TtFf and TTFF TtFf, TTFF and ttff TtFf and TtFF TtFf

In certain wild animals with normally black fur there occurs a very strange kind of coloring that is known as agouti. Each hair in the fur is black, but just below the tip, the hair has a band of yellow. With thousands of these yellow bands the fur of the animal does not look black. It has a mousy brown color. A strain of pure agouti mice was crossed with pure black mice. The result was ALL agouti mice. When the P2 offspring agouti mice were crossed with each other, the resulting offspring showed three times as many agouti mice as black mice. Which trait is dominant? Black Agouti white cannot be determined

Which of the following are true about DNA and RNA (select all that apply)? DNA is a much larger molecule than RNA DNA is double stranded while RNA is single stranded DNA contains the nucleotides ATCG while RNA contains the nucleotides AUCG DNA contains the sugar ribose while RNA contains the sugar deoxyribose

Indicate whether the genotype listed is heterozygous, homozygous recessive or homozygous dominant homozygous recessive heterozygous homozygous dominant

Color blindness is recessive, x-linked trait. In marriages between a man who is colorblind and a woman who is a carrier what percentage of the children can be expected to be sons who are not color blind? What percentage of the children can be expected to be daughters who are carriers? What percentage of the children can be expected to be daughters who are not carriers at all?

A pea plant is heterozygous for both seed shape and seed color. S is the allele for the dominant, spherical shape characteristic; s is the allele for the recessive, dented shape characteristic. Y is the allele for the dominant, yellow color characteristic; y is the allele for the recessive, green color characteristic. What genetic cross would give a phenotypic ratio of 9:3:3:1?

Brown eyes are dominant to blue eyes. What is the phenotype for a person with the following genotypes? BB Bb bb

What differs between two alleles of the same gene? The cell they're in. One might be in a liver cell and the other in a blood cell. The chromosome they're on. One might be on Chromosome 12 and the other on chromosome 3. Their location. One allele might be at the end of chromosome while the other allele is in the middle of another chromosome. Their base sequence. One allele might have the base sequence AGGTCTGA while the other has the base sequence GGTCTGT.

Which of the following is a result of T.H. Morgan and Lynch's (1912) study on linkage? phenotypic combinations in the F2 generation were not found in equal ratios no new phenotypic combinations appeared in the F2 generation inheritance in the F2 generation results in a 1:1:1:1 phenotypic ratio only recombinant phenotypes were present in the F2 generation

If genes are "sex-linked," then they are expressed only in women or only in men typically on the X chromosome only on the Y chromosome located next to one another

Assuming incomplete dominance, if a homozygous red-flowered plant (RR) is crossed with a homozygous white-flowered (rr) plant, what will be the color of the offspring? White red and white Red pink

Which discovery did Gregor Mendel make? Traits are inherited independently of each other. Traits are inherited as a tetrad. Traits are inherited as homologous pairs. Traits are inherited as a set, from one parent.

UV radiation is an ionization radiation that is useful for disinfecting surfaces True False

Cross a homozygous green plant with a heterozygous green plant.

Instructions: Students will need to show all work including writing out the crosses and the resulting gametes as well as Punnett squares. The final responses need to be marked with a box or circle around them. 1a) Mendel determined that yellow seeds is dominant to green seeds in peas. Cross a pea plant which is homozygous for yellow seeds with one which has green seeds. (Use capital letters for the dominant trait and the same letter in lower case for the recessive trait). What is the expected genotypic ratio of the offspring (F1)? What is the expected phenotypic ratio? 1b) If the F1 plants in the previous problem were allowed to self-fertilize, what is the expected genotypic ratio in the F2? What is the expected phenotypic ratio? Show the problem.

Snapdragon flower color is an example of incomplete dominance. A) Cross a white-flowering plant with a red-flowering plant. What are the expected genotypic and phenotypic ratios in the F1? B) Now cross two pink snapdragons. Give the expected genotypic and phenotypic ratios in the offspring.

In human blood types Type A and B are co-dominant while Type O is recessive to both A and B. If a Type A individual marries a Type O individual, can they have a Type O child? Why/why not? Can they have a Type AB child? Why/Why not?

Hemophilia is a recessive, sex-linked disease. a) A male with no history of hemophilia marries a woman whose father was a hemophiliac. Of their sons, what proportion would be expected to be hemophiliacs? What proportion of the daughters? What proportion of their total children would be expected to be carriers of the disease (having the gene, but not exhibiting the disease)? b) What if the male parent was a hemophiliac and the female parent had no history of the disease? (answer the same information as part a)

In summer squash, yellow fruit color dominates over white. A white-fruited plant is crossed with a yellow-fruited one and produced 51 white and 49 yellow fruited plants.

In alligators, rounded snout is dominant to a pointed snout. Cross a homozygous rounded snout alligator with a pointed snout alligator. What are the expected genotypic and phenotypic rations in the F2?

In humans, color-blindness is a recessive, sex-linked disease. A male who is color-blind marries a woman with normal vision but whose father was color-blind. OF THEIR SONS, how many can be expected to be color-blind? How many of their daughters can be expected to be color-blind? Are any of their children carriers of the disease (having the allele, but not expressing it)? How many? Are these carriers male or female?

In humans, blood Rh factor is an example of complete dominance (alleles for "positive" Rh factor completely dominate the "negative" allele). Blood type is an example of co-dominance. A person who is type AB and is heterozygous for Rh factor marries an individual who is O-. What are the chances that they will have a child with Type A+ blood? What are the chances that they will have a child with Type B- blood? Can they have a child with type O+ blood? Why or why not? (Hint: handle this as a di-hybrid cross).

3a) In tomatoes the skin may be smooth or hairy. Crosses between a true- breeding smooth-skinned tomato and a true-breeding hairy tomato produce all smooth fruit. (HINT: this should tell you which trait is dominant.) Show the Punnet Square for the problem and give the expected genotypic and phenotypic ratios in the offspring. 3b) Cross one of the F1 individuals from the previous problem with a homozygous smooth-skinned plant. Now cross the same F1 individual with a homozygous hairy plant. What are the expected genotypic and phenotypic ratios in the offspring?

In Pine trees, cones may be small or large. A true-breeding, small-coned plant is crossed with a true breeding large-coned plant. All offspring are large-coned. Which trait is dominant and which is recessive? How do you know?

A female who is color blind marries a male with no history of the condition. Show the problem. Of their children, what proportion would be expected to be color blind? Are these sons or daughters or both? Are any children carriers (having the gene, but not expressing the condition)? Are these sons or daughters or both?

Cross two pink-flowering Snapdragons. What are the expected genotypic and phenotypic ratios in their offspring?

A female with type A- blood marries a male with type AB+ blood. The female is heterozygous for blood type. The male is heterozygous for rh factor. Show the problem. What are the expected genotypic and phenotypic ratios in their offspring?

In sea horses long tail is dominant to short, and thick scales is dominant to thin. Cross two seahorses that are heterozygous for both traits. What are the expected genotypic and phenotypic ratios in the F1?

In Humans, long eyelashes is dominant to short. A female with long eyelashes marries a man who also has long eyelashes. They have a daughter with short eyelashes. How is this possible? Show the problem.

In Coleus plants, deep leaf margins are dominant over shallow leaf margins. Red leaves is dominant over green. If an individual that was heterozygous for both traits was crossed with a shallow-margined, green-leafed plant, what proportion of the F1 would have deep leaf margins AND red leaves? Show the problem.

A large-coned plant from the problem above is crossed with a small-coned plant. They produce 735 offspring. 351 offspring were small-coned, while 384 were large-coned. What are the genotypes of the parents? How do you know? Show the punnet square.

What are the two main sources of genetic variation in organisms? mutation and genetic drift gene flow and genetic drift natural selection and mutation mutation and sexual reproduction

In a group of cucumber plants, some individuals have bumpy fruit and others have smooth fruit. In this group, the gene for the fruit texture trait has two alleles. The allele F is for bumpy fruit, and the allele f is for smooth fruit. A certain cucumber plant from this group has bumpy fruit. This plant has one allele for bumpy fruit and one allele for smooth fruit. Based on this information, what is this cucumber plant's genotype for the fruit texture gene?

Inheritance and Expression of Traits:Question 5 Which molecule stores the instructions for various traits in an organism? Select one: Carbohydrate. Lipid. Protein. Deoxyribonucleic acid.

A deletion mutation causes three consecutive nucleotides to be removed from the DNA code. Which options describe the possible effects of this mutation? se all that apply: One amino acid may not be present. The rest of the amino acids would be in the protein in the correct order. The codons up to the affected region may be read incorrectly. The codons from the affected region onward may be read incorrectly. Three amino acids may not be present. The rest of the amino acids would be in the protein in the correct order.

Genetic Diversity and Population Survival:Question 9 Which of these results from making the sperm and egg cells needed for sexual reproduction? An introduction of a new gene into the organism. The loss of nucleotides from the DNA. An offspring that has the exact same genetic makeup as its parents. A large reshuffling of genetic information.

Synthesis of an inducible enzyme is started by the O inducer inactivating repressor O corepressor activating repressor and binding to operator O corepressor binding to the operator

Which of the following is the study of heredity and how genetic information is transferred from parents to their offspring? A. Genetics B. Biology C. Geneology

In dogs, the allele for straight hair (H) is dominant to the allele for curly hair (h). A straight-haired dog is crossed with another straight-haired dog. They produce only two puppies, one with straight hair and one with curly hair. Based on these results, what are the genotypes of the two parent dogs? A. One is heterozygous and the other is homozygous dominant B. One is homozygous dominant and the other is homozygous recessive C. One is heterozygous and the other is homozygous recessive D. Both are heterozygous

In Drosophila melanogaster, the black body (b*) is recessive to the gray body (b*), purple eyes (pr) are recessive to red eyes (pr*), and vestigial wings (vg) are recessive to normal wings (vg*). The loci encoding these traits are linked, with the map distances shown in the image. The interference among these genes is 0.5. A fly with a black body, purple eyes, and vestigial wings is crossed with a fly homozygous for a gray body, red eyes, and normal wings. The female progeny are then crossed with males that have a black body, purple eyes, and vestigial wings. If a total of 1000 progeny are examined, determine the expected number of offspring that result from each crossover event. double crossover: single crossover between b and pr: single crossover between vg and pr: