Question

The image above represents a human gamete, or reproductive cell. What evidence supports this claim?

Twenty-three individual (unpaired) chromosomes are shown in a round, yellow cell. The chromosomes are arranged in four rows from largest to smallest. Each chromosome has 3-4 black bands going across its width.

A
The cell contains half the normal number of chromosomes

B
The cell is round and the chromosomes are arranged in rows

C
There are 46 pairs of chromosomes present in the cell

D
Each chromosome contains half the normal number of genes
3
This image shows two adults and one of their offspring. Given the differences in their traits, which two statements must be true?

Two parents are shown in the bottom row of the picture. The father, shown on the left, has pale skin, blonde hair, and a cleft chin. The mother, shown on the right, has black hair, glasses, freckles, and pale skin. The child is shown above both parents. The child has black hair, pale skin, a cleft chin, and freckles.

The offspring is not likely to survive to adulthood

Each parent shares only some DNA with its offspring

All offspring of these parents are likely to look identical

The offspring is the result of asexual reproduction

The offspring is the result of sexual reproduction

Answer 1

### Question 1: Evidence supporting the claim that the cell is a human gamete

**Correct Answer: A - The cell contains half the normal number of chromosomes.**

**Evidence Explanation:**
Human gametes (sperm and egg cells) are haploid, meaning they contain half the normal chromosome number, which is 23 single chromosomes instead of the diploid number of 46 (23 pairs) found in somatic (body) cells. The presence of 23 unpaired chromosomes in the yellow cell aligns with this characteristic of gametes.

### Question 2: Statements that must be true based on the image of the parents and offspring

**Correct Answers: B - Each parent shares only some DNA with its offspring**
**E - The offspring is the result of sexual reproduction**

**Evidence Explanation:**
- **Option B:** In sexual reproduction, offspring inherit a combination of genes from both parents. Therefore, it is correct to say that each parent shares only some DNA with the offspring, as the offspring receives half of its genetic material from each parent.

- **Option E:** The description indicates that the offspring has traits from both parents, which is a requirement of sexual reproduction. Asexual reproduction would result in a genetically identical offspring to the parent, and that is not the case here, as the offspring shows a mix of traits from both parents.

### Incorrect Options Explanation:
- **The offspring is not likely to survive to adulthood:** This statement cannot be definitively determined based on the traits visible in the image.

- **All offspring of these parents are likely to look identical:** This statement is false because genetic variation occurs due to the combination of alleles from both parents, meaning each offspring can have a different combination of traits.

- **The offspring is the result of asexual reproduction:** This is incorrect as the traits of the offspring show a mix from both parents, which is indicative of sexual reproduction.