Evolution Lecture 5.4

Front 1

C-Value

Back 1

Total genome size

Front 2

C-Value Paradox

Back 2

We have unexpected/unanticipated genome sizes, given our knowledge of the size and complexity of the organism ex) Some amebae genomes dwarf that of humans

Front 3

Genome size and coding DNA are correlated in every group of organisms except...

Back 3

Land plants and animals

Front 4

In vertebrates, as cell size increases so does...

Back 4

genome size

Front 5

Prokaryotes have large population sizes, therefore

Back 5

Prokaryotes with slight advantages win out in the tense competition; therefore prokaryote genomes are highly compacted, few "extra" codons

Front 6

Bacterial genomes acquire nonhomologous genes via...

Back 6

Horizontal gene transfer: the movement of geneticmaterial between unicellular and/or multicellular organisms other than via vertical transmission (the transmission of DNA from parent to offspring.)

Front 7

What diminishes genome size in prokaryotes?

Back 7

Loss of DNA segments encoding active genes OR gene activation forms pseudogenes that are then lost by deletional bias

Front 8

What increases genome size in prokaryotes?

Back 8

Gene duplication OR acquisition of nonhomologous genes

Front 9

Deletional bias

Back 9

Most organisms (especially prokaryotes) are more likely to lose DNA than gain it; changes in DNA size are more likely to be losses rather than gains

Front 10

G-Value Paradox

Back 10

Despite differences in structural complexity, there is comparatively little variation in the number of coding genes or in the total amount of protein-coding sequence among eukaryotes.

Front 11

What percent of the human genome is coding for proteins?

Back 11

1.5%

Front 12

What percent of the human genome is transcribed?

Back 12

80%

Front 13

Three models of horizontal gene transfer

Back 13

Transduction, Transformation, and Conjugation

Front 14

Transduction

Back 14

The process by which foreign DNA is introduced into a cell by a virus or viral vector

Front 15

Transformation

Back 15

The genetic alteration of a cell resulting from the direct uptake and incorporation of exogenous genetic material from the cell's surroundings through the cell membrane(s).

Front 16

Conjugation

Back 16

The process by which one bacterium transfers genetic material to another through direct contact. During conjugation, one bacterium serves as the donor of the genetic material, and the other serves as the recipient.

Front 17

Introns

Back 17

Play a role in the control of expression, but why do eukaryotic organisms have introns while prokaryotic cells don't?

Front 18

"Jumping genes"

Back 18

Transposable elements

Front 19

Much of the "extra" DNA in organisms came from...

Back 19

transposable elements

Front 20

Transposable Elements

Back 20

Genes that contain information for their transposition (some leaving a copy behind as they move to a new position in the genomes). If these move into the coding sequence of a gene, that gene can be "knocked out." These are genomic parasites!

Front 21

LINE-1 Elements

Back 21

Long Interspersed Elements are autonomous transposons. These are not actively "jumping"

Front 22

SINE Elements

Back 22

Short Interspersed Elements are nonautonomous transposons, which means they are dependent on LINE-1 elements (includes Alu)

Front 23

Three processes that favor transposition

Back 23

--Transposition creates additional transposon copies within the genome

--Transposition onto an accessory genetic element (ex: plasmid) facilitates the movement of a transposon into a new genome

--Transposition copies an element from one chromosome to its homologue (in sexual diploid species), therefore ensuring that it will be present in all meiotic products