1. Warm-Up (1/22)
On the piece of white paper from the back, answer the following question.
Name
Date
Period
Illustrate (via model, diagram, cartoon, et cetera) how viral replication introduces genetic variation in the viral population.

2. 3C.1c: Errors in mitosis or meiosis can result in changes in phenotype.
3C.1c.1: Changes in chromosome number often result in new phenotypes, including sterility caused by triploidy and increased vigor of other polyploids.
3C.1c.2: Changes in chromosome number often result in human disorders with developmental limitations, including Trisomy 21 (Down syndrome) and XO (Turner syndrome).
3C.2b: The horizontal acquisitions of genetic information primarily in prokaryotes via transformation (uptake of naked DNA), transduction (viral transmission of genetic information), conjugation (cell-to-cell transfer), and transposition (movement of DNA segments within and between DNA molecules) increase variation.
3C.3a: Viral replication differs from other reproductive strategies and generates genetic variation via various mechanisms.
3C.3a.1: Viruses have highly efficient replicative capacities that allow for rapid evolution and acquisition of new phenotypes.
3C.3a.5: Related viruses can combine/recombine information if they infect the same host cell.
3C.3b: The reproductive cycles of viruses facilitate transfer of genetic information.
3C.3b.1: Viruses transmit DNA or RNA when they infect a host cell.
3C.3b.2: Some viruses are able to integrate into the host DNA and establish a latent (lysogenic) infection.

3. Chromosomal “Mutations” in Eukaryotes
Triploidy (3n) often results in sterility.
“nondisjunction” 1m 1p 1p 1m 2p 2m 2p 3p 3m 3p 2m 4m 3m 4p 4m 4p
2 copies of chr. 4
0 copies of chr. 4
uneven segregation 1m 2p 3p 4m
fertilization 4p
3 copies of chr. 4

4. Chromosomal “Mutations” in Eukaryotes
“Trisomy 21” results in Down’s Syndrome
A normal karyotype
Down’s syndrome karyotype

5. Chromosomal “Mutations” in Eukaryotes
Monoploidy (1n) of the sex chromosomes results in XO: Turner’s Syndrome
A normal karyotype
Turner’s Syndrome karyotype

6. Chromosomal “Mutations” in Eukaryotes
Genetically-modified polyploidy produces bigger, more productive crops.
Diploid (2n) banana
Tetraploid (4n) banana

7. Horizontal Transfer in Eukaryotes
Transposition of pieces of DNA occurs in eukaryotes
some chromosome
some other chromosome
“transposon”

8. Horizontal Transfer in Eukaryotes
Transposition of pieces of DNA occurs in eukaryotes
Barbara McClintock
Nobel Prize, 1983
~1940’s
Discovered a pigment transposon in maize

9. Horizontal Transfer in Prokaryotes
Plants and animals have sex, but bacteria can’t.
So how do they increase genetic variation?

10. Horizontal Transfer in Prokaryotes
Transformation is uptake of free-floating DNA by bacteria.
Added arabinose – GFP genes activated

11. Horizontal Transfer in Prokaryotes
Conjugation = bacterial “sex”

12. Horizontal Transfer in Prokaryotes
Transduction = injection of viral DNA

13. What’s the difference between horizontal and vertical transfer?
Horizontal Transfer
What’s the difference between horizontal and vertical transfer?

14. Critical Thinking Question #1
Compare and contrast the processes by which genetic variation is produced and maintained in prokaryotes versus eukaryotes.

15. 3C.1c: Errors in mitosis or meiosis can result in changes in phenotype.
3C.1c.1: Changes in chromosome number often result in new phenotypes, including sterility caused by triploidy and increased vigor of other polyploids.
3C.1c.2: Changes in chromosome number often result in human disorders with developmental limitations, including Trisomy 21 (Down syndrome) and XO (Turner syndrome).
3C.2b: The horizontal acquisitions of genetic information primarily in prokaryotes via transformation (uptake of naked DNA), transduction (viral transmission of genetic information), conjugation (cell-to-cell transfer), and transposition (movement of DNA segments within and between DNA molecules) increase variation.
3C.3a: Viral replication differs from other reproductive strategies and generates genetic variation via various mechanisms.
3C.3a.1: Viruses have highly efficient replicative capacities that allow for rapid evolution and acquisition of new phenotypes.
3C.3a.5: Related viruses can combine/recombine information if they infect the same host cell.
3C.3b: The reproductive cycles of viruses facilitate transfer of genetic information.
3C.3b.1: Viruses transmit DNA or RNA when they infect a host cell.
3C.3b.2: Some viruses are able to integrate into the host DNA and establish a latent (lysogenic) infection.

16. Transduction Produces Variation
Lysogenic viruses transfer bacterial genes to other bacteria.

17. The Lytic Cycle ∴, many generations turn over quickly.
Viral replication happens very quickly.
∴, many generations turn over quickly.
∴, viruses accumulate mutations and new phenotypes very quickly.
PLUS, retroviruses cannot error- check their RNA.
Lysis

18. Critical Thinking Question #2
Explain how a virus can transfer a bacterial gene from one host to another host.

19. Closure
On the piece of white paper from the back, answer the following question:
Name
Date
Period
Explain, referring to both prokaryotes and eukaryotes, how genetic variation in an organism results in phenotypic variation in populations.
Scale 1 – 10