Question

fruit fly (drosophila melanogaster) \\ carrot (daucus carota) \\ cacao (chocolate) (theobroma cacao) \\ red fox (vulpes vulpes) \\ mango (mangifera indica) \\ human (homo sapiens) \\ african hedgehog (atelerix algcris) \\ 8 \\ 18 \\ 20 \\ 34 \\ 40 \\ 46 \\ 90 \\ 2. how many chromosomes does a human skin cell have? \\ a. \underline{\hspace{1cm}} of those come from your dad and \underline{\hspace{1cm}} come from your mom. \\ 3. how many chromosomes does a human egg cell have? \underline{\hspace{1cm}} a sperm cell? \underline{\hspace{1cm}} \\ 4. when a human egg and a human sperm cell combine during fertilization, the single cell created, called a zygote, has \underline{\hspace{1cm}} chromosomes. \\ (options: 20, 34, 90, 23, 92, 9, 46)

Explanation:

Step1: Identify human skin cell ploidy

Human skin cells are somatic (diploid) cells. From the table, human (Homo sapiens) diploid chromosomes = $46$.

Step2: Split diploid chromosomes equally

Diploid cells get half chromosomes from each parent. Calculate: $\frac{46}{2}=23$.

Step3: Identify gamete chromosome count

Human egg/sperm cells are haploid (half of diploid). Calculate: $\frac{46}{2}=23$.

Step4: Calculate zygote chromosome count

Zygote forms from fusion of two haploid gametes. Calculate: $23+23=46$.

Answer:

1. How many chromosomes does a human skin cell have? $\boldsymbol{46}$

a. $\boldsymbol{23}$ of those come from your dad and $\boldsymbol{23}$ come from your mom.

1. How many chromosomes does a human egg cell have? $\boldsymbol{23}$; A sperm cell? $\boldsymbol{23}$
2. When a human egg and a human sperm cell combine during fertilization, the single cell created, called a zygote, has $\boldsymbol{46}$ chromosomes.