Question

directions: read the passage, then answer the questions that follow
growth and development
a scientist is studying the processes of growth and development in multicellular organisms. she is also
comparing these processes with similar processes in prokaryotes.

1. the scientist studies two cells from a multicellular organism. one cell is from the stomach of the

organism, while the other cell is from the skin. write one letter in each blank to correctly complete the
paragraph.
the cells nuclei would contain _ genetic information. the cells would express _
genes. the cells would most likely have _ structures and functions. the process by which the
cells would divide would be _.
a. different
b. the same

1. the scientist is going to make a model of a eukaryotic chromosome to show its features as it goes

through mitosis. which of these correctly describe elements of the model that the scientist should
include? circle the letters of all the correct statements.
a. the model should be single stranded.
b. the model should contain a centromere that connects sister chromatids.
c. the model should contain proteins called histones that the dna wraps around.

Explanation:

22.

• Genetic information: All cells in a multicellular organism (except gametes) have the same genetic information. So, the nuclei of the stomach and skin cells contain the same genetic information.
• Expressed genes: Different cell - types (like stomach and skin cells) express different genes. This is due to cell - specific gene regulation.
• Structures and functions: Stomach cells (e.g., parietal cells secrete hydrochloric acid) and skin cells (e.g., keratinocytes produce keratin) have different structures and functions.
• Cell division process: Somatic cells (like stomach and skin cells) divide by mitosis. Mitosis produces two daughter cells with the same genetic information as the parent cell.

• Option A: DNA in a eukaryotic chromosome is double - stranded. So, a model of a eukaryotic chromosome should not be single - stranded.
• Option B: During mitosis (and other cell - division processes), sister chromatids are connected by a centromere. This is an important structural feature of a chromosome model.
• Option C: Eukaryotic DNA wraps around histone proteins to form chromatin, which condenses to form chromosomes. So, a model of a eukaryotic chromosome should include histones.

Answer:

B, A, A, B

23.