EVOLUTION CONNECTION

Question

A typical prokaryotic cell has about 3,000 genes in its DNA , while a human cell has about 21,300 genes. About 1,000 of these genes are present in both types of cells. How do you explain how such different organisms could have this same subset of 1,000 genes?

A. The subset of genes shared by humans and prokaryotes originates from a common ancestor and has been retained over billions of years of evolution.
B. The subset of genes shared by humans and prokaryotes is the same due to the universality of the genetic code.
C. The subset of genes shared by humans and prokaryotes originates from random mutations that occurred and accumulated during billions of years of evolution.
D. The subset of genes shared by humans and prokaryotes have originated separately and is the same due to a similar environment.

Part B
What sorts of functions might these shared genes have?

A. regulation of DNA replication
B. coding for nuclear proteins
C. coding for ribosomal RNA
D. coding for crystallin proteins

Answer 1

Part A: The most suitable explanation for how such different organisms could have the same subset of 1,000 genes is:

A. The subset of genes shared by humans and prokaryotes originates from a common ancestor and has been retained over billions of years of evolution.

This answer highlights the concept of common descent, where genes that are essential for fundamental cellular processes were inherited from a common ancestor and have been preserved through evolutionary processes because of their essential functions.

Part B: The sorts of functions that these shared genes might have are most likely:

A. regulation of DNA replication
C. coding for ribosomal RNA

These functions are fundamental to all forms of life, regardless of complexity. Regulation of DNA replication is crucial for maintaining the integrity of genetic material during cell division, while ribosomal RNA is essential for protein synthesis, a core cellular process present in both prokaryotic and eukaryotic cells.