26. Prokaryotes

Prokaryote Reproduction and Gene Exchange

Bacterial Ribosome:  Microbiology

Conjugation

 No. Evolution is a product of genetic recombination. 

 No. Mutation produces new genetic possibilities, but it does not recombine them. 

 No. Endospore formation allows cells to survive adverse conditions, but it does not result in genetic recombination. 

Prokaryotes exchange genetic material when they are not reproducing.

In the absence of meiosis and sexual reproduction, what general process allows genetic recombination among prokaryotes?

What has metagenomic analysis allowed researchers to do for the first time?
a. sample organisms from an environment and grow them under defined conditions in the lab
b. isolate organisms from an environment and sequence their entire genome
c. study organisms that cannot be cultured (grown in the lab)
d. identify important morphological differences among species

Binary Fission in Bacteria | Cell Division | Biology GCSE (9-1) | kayscience.com

Biology - What is Binary fission? #12

Binary Fission, Transformation, and Transduction

Prokaryotic Ribosomes | 70S Ribosomes

What Is Asexual Reproduction | Genetics | Biology | FuseSchool

 replicate independently of the main chromosome 

 No. This statement is true, but there is a better answer. 

 often contain antibiotic resistance genes 

 are transferred from one bacterium to another by conjugation 

 can be involved in transfer of genetic material between prokaryotic cells 

 All of the listed responses are correct. 

Consider the large role plasmids play in the survival of bacterial cells.

Plasmids __________.

Bacteria (Updated)

E. coli have a very high mutation rate.

No. E. coli have a similar mutation rate to other prokaryotes and eukaryotes.

 The interior of the human colon is particularly mutagenic. 

 No. Although the typical American's diet may be higher in mutagenic chemicals than we would like, the human colon is not particularly mutagenic. 

 No. Transformation is a form of genetic recombination, not mutation. 

 No. Conjugation is a form of genetic recombination, not mutation. 

 A large population size and a rapid reproduction rate combine to produce many mutations without a particularly high mutation rate. 

How many E. coli cells inhabit the human gut?

How is it possible that as many as 9 million mutations can arise each day in the population of E. coli inhabiting one human?

 It requires transport of DNA by a virus. 

 No. Transduction is the transport of DNA by a virus. 

 It requires movement of DNA through a pilus. 

 No. DNA moves from one bacterium to another through a pilus in the process of conjugation. 

 It is a very rare phenomenon that happens by chance. 

 No. When it was originally discovered, scientists believed this was the case. Further research, however, has shown transformation to be an important process in many naturally occurring bacterial populations. 

 Although common in laboratory populations of bacteria, it does not play an important role in natural bacterial populations. 

 It can be facilitated by cell-surface proteins that recognize compatible DNA. 

Review horizontal gene transfer.

Which of the following statements about transformation is true?

Bacterial Genetics

 They can only carry one resistance gene for resistance to one antibiotic. 

 No. R plasmids may carry resistance genes for many antibiotics. 

 They can be transferred from one bacterium to another via conjugation. 

 No. This is true, but there is a better answer. 

 They can carry several resistance genes. 

 No, this is true, but there is a better answer. 

 Both the first and second statements are correct. 

 No. The first answer is not correct. R plasmids may carry resistance genes for many antibiotics. 

 Both the second and third answers are correct. 

The "R" refers to resistance.

Which of the following is/are true about R plasmids?

 Prokaryotes living in the food products will take in excess water and explode. 

 No. This is what would happen to prokaryotes in a hypotonic environment, if it weren't for their cell walls. 

 Salt is a toxin to prokaryotic cells and leads to their death. 

 No. Salt alone doesn't necessarily kill most prokaryotic cells. 

 Salt breaks down the chitin contained in the cell walls of prokaryotes. 

 No. Chitin is found in some eukaryotic cells. 

 Salt breaks down the peptidoglycan found in the capsule of prokaryotes. 

 No. Peptidoglycan is a component of the cell wall of bacteria, not the capsule. 

 Prokaryotic cells living in the food will shrink from their cell walls, impacting their ability to reproduce. 

Consider what happens to cells when they are placed in a hypertonic environment.

Why is salt a good preservative to use for foods such as pork and fish?

Binary Fission - How Do Bacteria Divide?  #12

Animation: Structure and Reproduction of Bacteria

Prokaryotes - Ribosomes and Inclusion Bodies

Asexual Reproduction-Fission-Budding-Fragmentation-Spores

No. An F+ cell acts as a donor during conjugation.

No. The F+ designation is used of bacteria that participate in conjugation.

No. The F+ designation refers to the cell's ability to form a pilus and transfer DNA to a receptor cell. It does not indicate the types of genes involved in the transfer.

 No. Fimbriae are attachment pili. Sex pili are used in conjugation. 

The F plasmid has a fertility factor.

An F+ bacterial cell __________.

Bacterial cell structure Part -4: cytoplasm and other cytoplasm components

Bacterial cell division and growth

Structure of Bacteria | Part 5 | Ribosomes

Mitosis and Binary Fission

Binary Fission | Cell Biology

Genetic variation in bacterial populations cannot result from
a. transduction.
b. conjugation.
c. mutation.
d. meiosis.

Bacteria are able to divide on a faster schedule than eukaryotic cells. Some bacteria can divide every 20 minutes, while the minimum time required by eukaryotic cells in a rapidly developing embryo is about once per hour, and most cells divide much less often than that. State at least two testable hypotheses explaining why bacteria can divide at a faster rate than eukaryotic cells.

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