Question

the chromosome theory
learning objective 18.1: given a micrograph or drawing of a cell youve never seen before, label chromosomes, chromatids, sister ch
cell.

which cells have 24 chromosomes? select all that apply.

☐ a haploid cell, with a haploid number of 24
☐ a triploid cell, with a haploid number of 8
☐ a haploid cell with 12 chromosomes after dna replication (12 \x\ shapes)
☐ a haploid cell with 24 chromosomes after dna replication (24 \x\ shapes)
☐ a diploid cell, with a haploid number of 12

Explanation:

Step1: Analyze each option

• Option 1: a haploid cell, with a haploid number of 24

A haploid cell has \( n \) chromosomes (where \( n \) is the haploid number). So if \( n = 24 \), the haploid cell has 24 chromosomes. Valid.

• Option 2: a triploid cell, with a haploid number of 8

Triploid cells have \( 3n \) chromosomes. If \( n = 8 \), then \( 3 \times 8 = 24 \). Valid.

• Option 3: a haploid cell with 12 chromosomes after DNA replication (12 "X" shapes)

After DNA replication, a haploid cell with \( n = 12 \) has 12 chromosomes (each as an "X" shape, but the total count is still 12, not 24). Invalid.

• Option 4: a haploid cell with 24 chromosomes after DNA replication (24 "X" shapes)

A haploid cell with \( n = 24 \) has 24 chromosomes before replication, and after replication, it still has 24 chromosomes (each as an "X"), so total is 24. Valid.

• Option 5: a diploid cell, with a haploid number of 12

Diploid cells have \( 2n \) chromosomes. If \( n = 12 \), then \( 2 \times 12 = 24 \). Valid.

Answer:

A. a haploid cell, with a haploid number of 24
B. a triploid cell, with a haploid number of 8
D. a haploid cell with 24 chromosomes after DNA replication (24 "X" shapes)
E. a diploid cell, with a haploid number of 12