IAG_23.docx!!!!!!!!!!!!!!!! IAG_23.docx IAG_23.docx
OpenStax Biology 2e Instructor Answer Guide
Biology 2e
Unit 5: Biological Diversity
Chapter 23: Protists
Visual Connection Questions
1. What evidence is there that mitochondria were incorporated into the ancestral eukaryotic
cell before chloroplasts?
All eukaryotic cells have mitochondria, but not all eukaryotic cells have chloroplasts.
2. Which of the following statements about Paramecium sexual reproduction is false?
c. The conjugate pair swaps macronuclei.
IAG_23.docx 4/20/2026, 2:15:29 PM IAG_23.docx
, IAG_23.docx!!!!!!!!!!!!!!!! IAG_23.docx IAG_23.docx
OpenStax Biology 2e Instructor Answer Guide
3. Which of the following statements about the Laminaria life cycle is false?
c. The gametophyte is diploid.
Review Questions
4. What event is thought to have contributed to the evolution of eukaryotes?
d. oxygenation of the atmosphere
5. Which characteristic is shared by prokaryotes and eukaryotes?
c. DNA-based genome
6. Mitochondria most likely evolved by _____________.
c. endosymbiosis
7. Which of these protists is believed to have evolved following a secondary endosymbiosis?
d. chlorarachniophytes
8. In 2016, scientists published the genome of Monocercomonoides, and demonstrated that
this organism has no detectable mitochondrial genes. However, its genome was arranged in
linear chromosomes wrapped around histones which are contained within the nucleus.
Monocercomonoides is therefore a(n) _________.
c. Eukaryote
9. Which of the following observations about a bacterium would distinguish it from the last
eukaryotic common ancestor?
b. Lack of a membrane-bound structure surrounding the genome
10. Protists that have a pellicle are surrounded by ______________.
d. proteins
IAG_23.docx 4/20/2026, 2:15:29 PM IAG_23.docx
OpenStax Biology 2e Instructor Answer Guide
Biology 2e
Unit 5: Biological Diversity
Chapter 23: Protists
Visual Connection Questions
1. What evidence is there that mitochondria were incorporated into the ancestral eukaryotic
cell before chloroplasts?
All eukaryotic cells have mitochondria, but not all eukaryotic cells have chloroplasts.
2. Which of the following statements about Paramecium sexual reproduction is false?
c. The conjugate pair swaps macronuclei.
IAG_23.docx 4/20/2026, 2:15:29 PM IAG_23.docx
, IAG_23.docx!!!!!!!!!!!!!!!! IAG_23.docx IAG_23.docx
OpenStax Biology 2e Instructor Answer Guide
3. Which of the following statements about the Laminaria life cycle is false?
c. The gametophyte is diploid.
Review Questions
4. What event is thought to have contributed to the evolution of eukaryotes?
d. oxygenation of the atmosphere
5. Which characteristic is shared by prokaryotes and eukaryotes?
c. DNA-based genome
6. Mitochondria most likely evolved by _____________.
c. endosymbiosis
7. Which of these protists is believed to have evolved following a secondary endosymbiosis?
d. chlorarachniophytes
8. In 2016, scientists published the genome of Monocercomonoides, and demonstrated that
this organism has no detectable mitochondrial genes. However, its genome was arranged in
linear chromosomes wrapped around histones which are contained within the nucleus.
Monocercomonoides is therefore a(n) _________.
c. Eukaryote
9. Which of the following observations about a bacterium would distinguish it from the last
eukaryotic common ancestor?
b. Lack of a membrane-bound structure surrounding the genome
10. Protists that have a pellicle are surrounded by ______________.
d. proteins
IAG_23.docx 4/20/2026, 2:15:29 PM IAG_23.docx
