Question

1) Which of the following statements is false?

There are few undescribed species of prokaryotes.

Analysis of DNA sequences is a useful tool for studying prokaryotic diversity.

Many prokaryotes have been difficult or impossible to grow in the lab.

Horizontal gene transfer may make it difficult to infer prokaryote phylogenies.

2) One of the ways in which horizontal gene transfer can occur between species is if a virus carries DNA from one host cell to another. Which of the following describes this form of gene flow?

Transduction

Transformation

Conjugation

Commensalism

3) Which of the following is true of secondary endosymbiosis?

It occurred only once, when a nonphotosynthetic eukaryote engulfed a cyanobacterium.

It was the origin of the chloroplasts found in land plants.

It is indicated by the presence of a double membrane surrounding the endosymbiont.

It occurs when an organism containing an endosymbiont is engulfed by another organism, and becomes an endosymbiont itself.

Answer 1

1) Horizontal gene transfer may make it difficult to infer prokaryote phylogenies.

Horizontal gene transfer(HGT) were earlier thought to create difficulty while making prokaryotic phylogenies but some methods like supertree are quite robust to HGT. Even though incongruency was observed while comparing gene trees but they were not indicative of HGT. Although when observed in eukaryotes HGT showed more difficulty than in prokaryotes

2) Transduction

It is a process of gene flow where foreign gene is inserted into an organism with the help of viral vector. So here in horizontal gene transfer between bacterias the gene transfer done by virus will also be called as transduction.

3) It occurs when an organism containing an endosymbiont is engulfed by another organism, and becomes an endosymbiont itself.

Endosymbiotic is a process in which a free living cell ingulfs another cell and they live in a symbiotic relationship. This is known as primary endosymbiosis, when those cells are again engulfed by another independently living cell then it is known as secondary endosymbiosis.