Term
| How do bacteria produce genetic diversity? |
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Definition
| Replication and genetic transfer |
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Term
| How does genetic diversity occur in replication? |
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Definition
Errors that occur in DNA replication
-DNA replicates frequently in bacteria |
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Term
| How does genetic diversity occur in genetic transfer? |
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Definition
| Exchange portions of their genomes |
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Term
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Definition
| an archaea that has about 1/3 of their genome come from other bacteria |
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Term
| What does genetic transfer in bacteria allow? |
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Definition
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Term
| What are three types of genetic transfer in bacteria |
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Definition
Transduction
Conjugation
Transformation |
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Term
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Definition
Virus mediated transfer of DNA from one cell to another
No direct contact between cells needed |
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Term
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Definition
- Direct transfer of DNA from one cell to another (Requires physical connection-- Sex pilus – modified fimbria
- Involves transfer of ‘F factor’- Contains genes for conjugation and a replication start site
-Can be found in two possible locations:
On plasmid
On chromosome
A cell without F factor (‘F-’) is the recipient |
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Term
| What does conjugation require? |
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Definition
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Term
| Where can the f factor be found? |
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Definition
on the plasmid
on chromosome |
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Term
| What is the recipient when compared to f factor? |
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Definition
| A cell without F factor (F-) |
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Term
| Describe F+ conjugation on the plasmid process |
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Definition
F factor is located on a special F plasmid (Cell with F plasmid is 'F+')
Sex pilus forms connecting cells
One strand of F plasmid crosses to recipient ( 'rolling circle' replication in donor)
Transferred DNA serves as template for synthesis of other strand, is circularized to form F plasmid in recipient cell, making it F+
Other genes can insert into plasmid,pass along with F factor |
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Term
| Describe Hfr and the process |
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Definition
F factor is located on genome
Sex pilus forms, connecting cells
One strand of chromosome crosses to recipient
('rolling circle' replication in donor)
Genome is too bug, take too long to pass in its entirety: amount transferred is time-dependent (used to make early map of E. coli genome, in minutes)
Transferred DNA recombines with recipient genome ( some incorporated, some degraded) |
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Term
| What are the two processes called when the f factor is positive? |
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Definition
F+ conjugation= plasmid
Hfr conjugation=chromosome |
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Term
| What is transformation in bacteria? |
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Definition
| Bacteria pick up DNA from environment |
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Term
| What are two examples of transformation in bacteria? |
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Definition
-One bacterium dies and another scavenges pieces of its DNA
-Can be trans-species (sushi) gut bacteria is passed down after being picked up after eating by parents |
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Term
| How can transformation occur in eukaryotes? |
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Definition
| mechanism of germ-line incorporation unclear |
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Term
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Definition
| Th presence of multiple traits in a population |
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Term
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Definition
a heritable feature that is polymorphoc
ex) fur color or earlobe attachment |
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Term
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Definition
the individual variants of a character
ex)black fur vs orange fur
attached earlobe vs unattached |
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Term
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Definition
| Belief that the progeny are just little copies of the parent |
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Term
| What is the blending hypothesis? |
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Definition
Belief that children are intermediate between the two parents
-represent the product of averaging all of the traits of parents
-could not be unblended-would lead to uniform population
-children would all be at the same half-way point
-children could never have a characteristic not seen in parents, or more extreme than those seen in parents |
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Term
| What is Mendelian genetics? |
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Definition
Named for Gregor Mendel
Studied genetics of pea plant |
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Term
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Definition
-Good model system
Many distinct varieties
Easy to self and cross fertilize
Fast generation time
Many offspring |
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Term
| What does mendelian genetics look at? |
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Definition
Genetic variation derives form different versions of the same gene (allele)
Diploid organisms have two alleles
One on each paired chromosome, one from each parent |
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Term
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Definition
| different versions of the same gene |
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Term
| What are the results of mendelian genetics? |
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Definition
the characteristics of some alleles dominate over others
-not blending, but all or nothing
Dominant
Recessive |
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Term
| What is the law of segregation? |
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Definition
In diploid organisms, the two alleles are inherited from different parents and end up in different gametes
-traits passed as units
-no blending
-studied through controlled breeding
(Carry out a specific cross, observe results) |
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Term
| How do you follow the law of segregation? |
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Definition
By following over successive generations
P generation
F1 generation
F2 generation |
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Term
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Definition
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Term
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Definition
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Term
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Definition
second 'filial'
from self-cross between F1 |
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Term
| What is a monohybrid cross? |
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Definition
| ◦ Study of the genetics of a single trait |
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Term
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Definition
| observed trait (visible characteristics) |
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Term
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Definition
| genetic makeup responsible for observed trait (what the different traits are) |
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Term
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Definition
| both alleles for a gene are the same |
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Term
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Definition
| The two alleles are different |
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Term
| What does the letter usually represent when describing traits? |
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Definition
Letter usually represents trait that differs from what is normal for a
population (‘wild type’)
Capital is for dominant
Small of same letter for
recessive
‘+’ sometimes used to
represent wild type |
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