chapter 11 mastery test a, continued
part c answer each question.
16. what organisms did gregor mendel experiment with? what did his experiments show?

17. how do sex cells differ from other cells in the human body?

18. give one example of selective breeding.

19. draw a punnett square for qq and qq. explain what the punnett square represents.

20. name and describe two diseases caused by recessive genes.

Question

chapter 11 mastery test a, continued
part c answer each question.
16. what organisms did gregor mendel experiment with? what did his experiments show?

17. how do sex cells differ from other cells in the human body?

18. give one example of selective breeding.

19. draw a punnett square for qq and qq. explain what the punnett square represents.

20. name and describe two diseases caused by recessive genes.

Accepted Answer

### Question 16
# Brief Explanations:
Gregor Mendel experimented with pea plants (Pisum sativum). His experiments showed the principles of inheritance, including the law of segregation (each individual has two alleles for a trait, which separate during gamete formation) and the law of independent assortment (alleles of different genes assort independently during gamete formation), and he also identified dominant and recessive traits.
# Answer:
Organisms: Pea plants (Pisum sativum). Experiments showed: Principles of inheritance (law of segregation, law of independent assortment, dominant/recessive traits).

### Question 17
# Brief Explanations:
Sex cells (gametes: sperm in males, eggs in females) differ from other body cells (somatic cells) in several ways. Somatic cells are diploid (have 2 sets of chromosomes, 46 in humans), while sex cells are haploid (have 1 set of chromosomes, 23 in humans). Somatic cells divide by mitosis for growth/repair, sex cells divide by meiosis to produce haploid gametes. Also, somatic cells have the full genetic complement for the individual, while sex cells carry half to combine with another gamete during fertilization.
# Answer:
Sex cells (gametes) are haploid (23 chromosomes in humans), somatic cells are diploid (46). Sex cells form via meiosis, somatic via mitosis. Sex cells combine in fertilization, somatic cells for growth/repair.

### Question 18
# Brief Explanations:
Selective breeding (artificial selection) is when humans breed organisms for desired traits. An example is breeding different dog breeds: humans selected dogs with traits like size, coat type, or temperament (e.g., breeding Chihuahuas for small size, or German Shepherds for working ability). Another example: breeding wheat for higher yield or disease resistance, or breeding cows for more milk production.
# Answer:
Example: Breeding different dog breeds (e.g., Chihuahuas for small size) by selecting dogs with desired traits. (Or: Breeding wheat for higher yield; Breeding dairy cows for more milk.)

### Question 19
# Explanation:
## Step1: Determine gametes
For parent 1 (Qq), the possible gametes are Q and q (since during meiosis, the alleles separate). For parent 2 (QQ), the possible gametes are only Q (as both alleles are Q, so they separate into Q gametes).
## Step2: Create Punnett square
|   | Q (from QQ) | Q (from QQ) |
|---|---|---|
| Q (from Qq) | QQ | QQ |
| q (from Qq) | Qq | Qq |
## Step3: Explain the Punnett square
The Punnett square represents the possible genetic combinations (genotypes) of the offspring from the cross between Qq and QQ. It shows the probability of each genotype: 50% QQ and 50% Qq. It helps predict the inheritance of traits by visualizing how alleles from each parent can combine.
# Answer:
Punnett square:
|   | Q | Q |
|---|---|---|
| Q | QQ | QQ |
| q | Qq | Qq |

Explanation: The Punnett square shows possible offspring genotypes (QQ, QQ, Qq, Qq) from crossing Qq and QQ, predicting trait inheritance probability (50% QQ, 50% Qq).

### Question 20
# Brief Explanations:
1. Cystic Fibrosis: Caused by a recessive allele (mutations in the CFTR gene). Affects the respiratory and digestive systems, causing thick, sticky mucus that clogs lungs and ducts in organs like the pancreas. A person needs two recessive alleles (cc) to have the disease; carriers (Cc) are unaffected.
2. Sickle - Cell Anemia: Caused by a recessive allele (mutation in the hemoglobin gene). Red blood cells become sickle - shaped, leading to reduced oxygen transport, pain, and organ damage. Requires two recessive alleles (ss) for the disease; carriers (Ss) may have some resistance to malaria.
# Answer:
1. Cystic Fibrosis: Recessive gene - caused (CFTR gene mutation). Causes thick mucus in lungs/pancreas; needs two recessive alleles (cc).
2. Sickle - Cell Anemia: Recessive gene - caused (hemoglobin gene mutation). Sickle - shaped RBCs, pain/organ damage; needs two recessive alleles (ss).

Sovi.AI - AI Math Tutor

QUESTION IMAGE

Question

Explanation:

Question 16

Answer:

Question 17