Question

question 5

which of the following was not part of the original cell theory, but was added later after we learned more about cellular structure?

• all cells have the same exact structures
• all cells come from pre-existing cells
• all cells have a nucleus
• all cells have the same basic composition

question 6

which types of cells have dna?

• all cells have dna
• only eukaryotes
• only prokaryotes

Explanation:

Analyze classical cell theory

The first question asks which statement was not part of the original cell theory but was added later as our understanding of cellular structure advanced. Classical Cell Theory was formulated by Schleiden, Schwann, and Virchow, stating that all living organisms are composed of cells, the cell is the basic unit of life, and all cells arise from pre-existing cells. Modern cell theory expanded on this by adding that all cells have the same basic chemical composition and metabolic processes.

Evaluate the options for Question 5

• "all cells have the same exact structures": This is biologically incorrect, as prokaryotic and eukaryotic cells differ significantly.
• "all cells come from pre-existing cells": This was part of the classical cell theory (Virchow's contribution).
• "all cells have a nucleus": This is incorrect, as prokaryotes lack a nucleus.
• "all cells have the same basic composition": This is a tenet of modern cell theory, added later as biochemical techniques advanced.

Analyze DNA distribution in cells

The second question asks which types of cells have DNA. DNA is the universal genetic material for all living organisms. Both prokaryotic cells (which have circular DNA in a nucleoid region) and eukaryotic cells (which have linear DNA enclosed in a nucleus) contain DNA to direct cellular activities and pass on genetic information.

Evaluate the options for Question 6

• "all cells have DNA": This is correct because DNA is a universal requirement for cellular life.
• "only eukaryotes": This is incorrect because prokaryotes (bacteria and archaea) also contain DNA.
• "only prokaryotes": This is incorrect because eukaryotes also contain DNA.

Answer:

Question 5

• all cells have the same exact structures
• all cells come from pre-existing cells
• all cells have a nucleus
• all cells have the same basic composition (Correct answer)

Question 6

• all cells have DNA (Correct answer)
• only eukaryotes
• only prokaryotes