
Concept explainers
To determine: The possible genotypes of children born if a individual who is heterozygous for a recessive mutation in enzyme 1 and enzyme 2 marries an individual having the same genotype.
Introduction:

Explanation of Solution
It is given that both the individuals are heterozygous for a recessive mutation of enzymes 1 and 2. To find the possible genotypes of their children, genotypes of parents can be assumed as:
R represents normal enzyme 1 and r shows mutated enzyme 1. D shows normal enzyme 2 and d shows mutated enzyme 2.
Both the parents are heterozygous for the recessive mutation in both the enzymes. So the gametes produced by these parents will be RD, Rd, rD, and rd.
Genotype of the children from these gametes can be determined as follows:
RD | Rd | rD | rd | |
RD | RRDD | RRDd | RrDD | RrDd |
Rd | RRDd | RRdd | RrDd | Rrdd |
rD | RrDD | RrDd | rrDD | rrDd |
rd | RrDd | Rrdd | rrDd | rrdd |
GenotypesRRDD, RRDd, RrDD, RrDd, RRDd, RrDd, RrDD, RrDd, and RrDd will not show any mutation in any of the enzymes.
Genotypes rrDD, rrDd, and rrDd will show mutation in enzyme 1 only.
Genotypes RRdd, Rrdd, and Rrdd will show mutation in enzyme 2 only.
Genotype rrdd will show mutation in both the enzymes 1 and 2.
To determine: The activity ofenzyme 1 and enzyme 2 for all the genotypes that are produced in children if an individual who is heterozygous for a recessive mutation in both, enzyme 1 and enzyme 2, marries an individual having the same genotype, assuming that there is 0% activity for mutant alleles and 50% activity in normal alleles.
Introduction: Metabolic pathways are catalyzed using enzymes. These enzymes are synthesized based on information provided by the genes.. Any type of change in these genes can hinder the synthesis of these enzymes or lead to synthesis of faulty enzymes. Heterozygosity is when same copies of alleles are present for a gene and homozygosity is when different copies of alleles are present for a gene.

Explanation of Solution
The possible genotypes of children born from parents who are heterozygous for a recessive mutation in both the enzymes are determined as follows:
R represents normal enzyme 1 and r shows mutated enzyme 1. D shows normal enzyme 2 and d shows mutated enzyme 2.
Both the parents are heterozygous for the recessive mutation in both the enzymes. So the gametes produced by these parents will be RD, Rd, rD, and rd.
Genotype of the children from these gametes can be determined as follows:
RD | Rd | rD | rd | |
RD | RRDD | RRDd | RrDD | RrDd |
Rd | RRDd | RRdd | RrDd | Rrdd |
rD | RrDD | RrDd | rrDD | rrDd |
rd | RrDd | Rrdd | rrDd | rrdd |
Genotypes RRDD, RRDd, RrDD, RrDd, RRDd, RrDd, RrDD, RrDd, and RrDd will not show any mutation in any of the enzymes. Hence, both the enzymes will show 50% activity in these genotypes
Genotypes rrDD, rrDd, and rrDd will show mutation in enzyme 1 only. Hence, in children with these genotypes, enzyme 1 will show 0% activity and enzyme 2 will show 50 % activity.
Genotypes RRdd, Rrdd, and Rrdd will show mutation in enzyme 2 only. Hence, in children with these genotypes, enzyme 1 will show 50% activity and enzyme 2 will show 0% activity.
Genotype rrdd will show mutation in both the enzymes 1 and 2. Hence, in children with these genotypes, both, enzyme 1 and enzyme 2 will show 0% activity.
To determine: Whether compound C will be made or not in each genotype of children born, if an individual who is heterozygous for a recessive mutation in both, enzyme 1 and enzyme 2, marries an individual having the same genotype, and if compound C not produced, the compounds that will be in excess.
Introduction: Metabolic pathways are catalyzed using enzymes. These enzymes are synthesized based on information provided by the genes.. Any type of change in these genes can hinder the synthesis of these enzymes or lead to synthesis of faulty enzymes. Heterozygosity is when same copies of alleles are present for a gene and homozygosity is when different copies of alleles are present for a gene.

Explanation of Solution
Genotype RRDD will not show any mutation in any of the enzymes. So, all the compounds will be present in their adequate amounts.
Genotype RRDd will not show any mutation in any of the enzymes. So, all the compounds will be present in their adequate amounts.
Genotype RrDD will not show any mutation in any of the enzymes. So, all the compounds will be present in their adequate amounts
Genotype RrDd will not show any mutation in any of the enzymes. So, all the compounds will be present in their adequate amounts
Genotype RRDd will not show any mutation in any of the enzymes. So, all the compounds will be present in their adequate amounts
Genotype RRdd will show mutation in enzyme 2 only. Hence, compound C will not be produced while there will be an excess production of compound B. Compound A will be present in normal amounts.
Genotype RrDd will not show any mutation in any of the enzymes. So, all the compounds will be present in their adequate amounts
Genotype Rrdd will show mutation in enzyme 2 only. Hence, compound C will not be produced while there will be an excess production of compound B. Compound A will be present in normal amounts.
Genotype RrDD will not show any mutation in any of the enzymes. So, all the compounds will be present in their adequate amounts
Genotype RrDd will not show any mutation in any of the enzymes. So, all the compounds will be present in their adequate amounts
Genotype rrDD will show mutation in enzyme 1 only. So there will be no production of compound B as mutated enzyme 1 will not be able to act on compound A. Absence of compound B will cause no production of compound C. Here, compound A will be present in excess.
Genotype rrDd will show mutation in enzyme 1 only. So there will be no production of compound B as mutated enzyme 1 will not be able to act on compound A. Absence of compound B will cause no production of compound C. Here, compound A will be present in excess.
Genotype RrDd will not show any mutation in any of the enzymes. So, all the compounds will be present in their adequate amounts
Genotype Rrdd will show mutation in enzyme 2 only. Hence, compound C will not be produced while there will be an excess of compound B. Compound A will be present in normal amounts.
Genotype rrDd will show mutation in enzyme 1 only. So there will be no production of compound B as mutated enzyme 1 will not be able to act on compound A. Absence of compound B will cause no production of compound C. Here, compound A will be present in excess.
Genotype rrdd will show mutation in both, enzyme 1 and enzyme 2. Hence no compound will be metabolized and compound C will not be produced.
Want to see more full solutions like this?
Chapter 10 Solutions
Human Heredity: Principles and Issues (MindTap Course List)
- 10. Your instructor will give you 2 amino acids during the activity session (video 2-7. A. First color all the polar and non-polar covalent bonds in the R groups of your 2 amino acids using the same colors as in #7. Do not color the bonds in the backbone of each amino acid. B. Next, color where all the hydrogen bonds, hydrophobic interactions and ionic bonds could occur in the R group of each amino acid. Use the same colors as in #7. Do not color the bonds in the backbone of each amino acid. C. Position the two amino acids on the page below in an orientation where the two R groups could bond together. Once you are satisfied, staple or tape the amino acids in place and label the bond that you formed between the two R groups. - Polar covalent Bond - Red - Non polar Covalent boND- yellow - Ionic BonD - PINK Hydrogen Bonn - Purple Hydrophobic interaction-green O=C-N H I. H HO H =O CH2 C-C-N HICK H HO H CH2 OH H₂N C = Oarrow_forwardFind the dental formula and enter it in the following format: I3/3 C1/1 P4/4 M2/3 = 42 (this is not the correct number, just the correct format) Please be aware: the upper jaw is intact (all teeth are present). The bottom jaw/mandible is not intact. The front teeth should include 6 total rectangular teeth (3 on each side) and 2 total large triangular teeth (1 on each side).arrow_forward12. Calculate the area of a circle which has a radius of 1200 μm. Give your answer in mm² in scientific notation with the correct number of significant figures.arrow_forward
- Describe the image quality of the B.megaterium at 1000X before adding oil? What does adding oil do to the quality of the image?arrow_forwardWhich of the follwowing cells from this lab do you expect to have a nucleus and why or why not? Ceratium, Bacillus megaterium and Cheek epithelial cells?arrow_forward14. If you determine there to be debris on your ocular lens, explain what is the best way to clean it off without damaging the lens?arrow_forward
- 11. Write a simple formula for converting mm to μm when the number of mm's is known. Use the variable X to represent the number of mm's in your formula.arrow_forward13. When a smear containing cells is dried, the cells shrink due to the loss of water. What technique could you use to visualize and measure living cells without heat-fixing them? Hint: you did this technique in part I.arrow_forward10. Write a simple formula for converting μm to mm when the number of μm's are known. Use the variable X to represent the number of um's in your formula.arrow_forward
- 8. How many μm² is in one cm²; express the result in scientific notation. Show your calculations. 1 cm = 10 mm; 1 mm = 1000 μmarrow_forwardFind the dental formula and enter it in the following format: I3/3 C1/1 P4/4 M2/3 = 42 (this is not the correct number, just the correct format) Please be aware: the upper jaw is intact (all teeth are present). The bottom jaw/mandible is not intact. The front teeth should include 6 total rectangular teeth (3 on each side) and 2 total large triangular teeth (1 on each side).arrow_forwardAnswer iarrow_forward
- Human Heredity: Principles and Issues (MindTap Co...BiologyISBN:9781305251052Author:Michael CummingsPublisher:Cengage LearningHuman Biology (MindTap Course List)BiologyISBN:9781305112100Author:Cecie Starr, Beverly McMillanPublisher:Cengage Learning
- Biology Today and Tomorrow without Physiology (Mi...BiologyISBN:9781305117396Author:Cecie Starr, Christine Evers, Lisa StarrPublisher:Cengage Learning


