heredity
directions study the punnett square shown. read each statement. answer the questions on the lines provided.
punnett square: top row r, r; left column r, r; cells rr, rr, rr, rr
1. what genotype do both parents have?
2. what letter represents the recessive gene?
3. what letter represents the dominant gene?
4. what genotypes could an offspring have?
5. if r is a recessive gene, which offspring could exhibit the recessive trait?
6. if r is dominant over r, what is the chance that an offspring will exhibit the dominant trait?
7. is an offspring more likely to have a genotype rr or rr? explain.
8. if r is dominant and represents red flowers, which genotypes will have the phenotype for red flowers?
9. if r is dominant and represents red flowers, what is the chance that the offspring with the genotype rr will have white flowers?
10. what is the chance that an offspring will not receive a dominant gene?
11. which genotype has a 50 percent chance of being inherited?
12. could these parents have three offspring with the genotype rr? explain.
directions draw a punnett square for each of the crosses listed below.
13. rr rr
14. yy yy
15. qq qq

Question

Accepted Answer

### Question 1
# Explanation:
## Step1: Analyze Punnett square structure
In a Punnett square, the top row and left column represent the parents' gametes. Here, parents contribute R and r (since the rows/columns are R and r for both, implying each parent has one R and one r).
## Step2: Determine genotype
A genotype with one dominant (R) and one recessive (r) allele is heterozygous, so the genotype is Rr.
# Answer: Rr

### Question 2
# Explanation:
## Step1: Recall recessive gene notation
Recessive genes are typically represented by lowercase letters. In the Punnett square, the lowercase letter is r.
## Step2: Confirm with genetics principles
Lowercase letters denote recessive alleles, so r is the recessive gene.
# Answer: r

### Question 3
# Explanation:
## Step1: Recall dominant gene notation
Dominant genes are typically represented by uppercase letters. In the Punnett square, the uppercase letter is R.
## Step2: Confirm with genetics principles
Uppercase letters denote dominant alleles, so R is the dominant gene.
# Answer: R

### Question 4
# Explanation:
## Step1: Identify offspring genotypes from Punnett square
The Punnett square cells show RR, Rr, Rr, and rr. So the possible genotypes are the ones present in these cells.
## Step2: List unique genotypes
From the square, the genotypes are RR, Rr, and rr.
# Answer: RR, Rr, rr

### Question 5
# Explanation:
## Step1: Recall recessive trait expression
A recessive trait is expressed only when the genotype is homozygous recessive (rr), as dominant alleles (R) mask recessive ones.
## Step2: Identify offspring with rr
From the Punnett square, the offspring with genotype rr will exhibit the recessive trait.
# Answer: The offspring with genotype rr

### Question 6
# Explanation:
## Step1: Count dominant trait offspring
Dominant trait is expressed in RR, Rr, Rr (since R is dominant). So that's 3 out of 4 offspring.
## Step2: Calculate probability
Probability = $\frac{	ext{Number of dominant trait offspring}}{	ext{Total offspring}} = \frac{3}{4}$ or 75%.
# Answer: $\frac{3}{4}$ (or 75%)

### Question 7
# Explanation:
## Step1: Count Rr and RR occurrences
In the Punnett square, Rr appears 2 times, RR appears 1 time.
## Step2: Compare frequencies
Since 2 > 1, Rr is more likely. The number of Rr genotypes (2) is greater than RR (1) in the 4 - cell Punnett square.
# Answer: Yes, Rr is more likely. Rr appears 2 times, RR appears 1 time in the Punnett square, so Rr has a higher frequency.

### Question 8
# Explanation:
## Step1: Recall dominant phenotype expression
A dominant phenotype (red flowers here) is expressed in genotypes with at least one dominant allele (R). So RR (homozygous dominant) and Rr (heterozygous) will show the dominant phenotype.
## Step2: Identify genotypes from Punnett square
From the square, RR, Rr, Rr have at least one R, so these genotypes show red flowers.
# Answer: RR, Rr

### Question 9
# Explanation:
## Step1: Recall phenotype determination
For a genotype Rr, the dominant allele (R) is present, so the phenotype will be red (dominant trait). White flowers are the recessive trait, expressed only in rr.
## Step2: Determine probability
Since Rr has R, it will show red, so the chance of white flowers is 0.
# Answer: 0 (or 0%)

### Question 10
# Explanation:
## Step1: Identify offspring without dominant gene (R)
Offspring without R will have genotype rr (only one such offspring in the 4 - cell square).
## Step2: Calculate probability
Probability = $\frac{	ext{Number of rr offspring}}{	ext{Total offspring}} = \frac{1}{4}$ or 25%.
# Answer: $\frac{1}{4}$ (or 25%)

### Question 11
# Explanation:
## Step1: Count occurrences of each genotype
RR: 1, Rr: 2, rr: 1.
## Step2: Calculate percentage for each
RR: $\frac{1}{4} = 25\%$, Rr: $\frac{2}{4} = 50\%$, rr: $\frac{1}{4} = 25\%$. So Rr has a 50% chance.
# Answer: Rr

### Question 12
# Explanation:
## Step1: Recall probability of rr per offspring
The probability of an offspring being rr is $\frac{1}{4}$ (25%).
## Step2: Analyze multiple offspring probability
Each offspring is an independent event. Although the probability of one rr is 25%, with three offspring, it is possible (though less likely) because each birth is independent, and the 25% chance per offspring means there's a non - zero probability of getting three rr offspring.
# Answer: Yes. The probability of an offspring being rr is 25% (1/4). Since each offspring's genotype is an independent event, it is possible (though the probability is (1/4)^3 = 1/64) for three offspring to have genotype rr.

### Question 13 (Drawing Punnett square for Rr × rr)
# Explanation:
## Step1: Determine gametes
Parent 1 (Rr) produces R and r gametes. Parent 2 (rr) produces r and r gametes.
## Step2: Construct Punnett square
|   | R | r |
|---|---|---|
| r | Rr | rr |
| r | Rr | rr |
# Answer: The Punnett square is:

|   | R | r |
|---|---|---|
| r | Rr | rr |
| r | Rr | rr |

### Question 14 (Drawing Punnett square for YY × yy)
# Explanation:
## Step1: Determine gametes
Parent 1 (YY) produces Y and Y gametes. Parent 2 (yy) produces y and y gametes.
## Step2: Construct Punnett square
|   | Y | Y |
|---|---|---|
| y | Yy | Yy |
| y | Yy | Yy |
# Answer: The Punnett square is:

|   | Y | Y |
|---|---|---|
| y | Yy | Yy |
| y | Yy | Yy |

### Question 15 (Drawing Punnett square for Qq × Qq)
# Explanation:
## Step1: Determine gametes
Parent 1 (Qq) produces Q and q gametes. Parent 2 (Qq) produces Q and q gametes.
## Step2: Construct Punnett square
|   | Q | q |
|---|---|---|
| Q | QQ | Qq |
| q | Qq | qq |
# Answer: The Punnett square is:

|   | Q | q |
|---|---|---|
| Q | QQ | Qq |
| q | Qq | qq |

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QUESTION IMAGE

Question

Explanation:

Question 1

Step1: Analyze Punnett square structure

Step2: Determine genotype

Step1: Recall recessive gene notation

Step2: Confirm with genetics principles

Step1: Recall dominant gene notation

Step2: Confirm with genetics principles

Answer:

Question 2