Ch 13: transposable elements

true or false mobile genetic elements prevent exons from moving from one gene to another

false, they move exons from one gene to another

each ____ is made up of a particular set of alleles at each SNP

haplotype

Transposable elements are more likely to reside in ______________ so that there will be ____________ rate of transposition throughout the host genome a. euchromatin lowe b. euchromatin higher c. heterochromatin lower d. heterochromatin higher

heterochromatin, lower

Double strander rna is loaded on the dicer and the dicer processes it into mature RNA. then its bound by the risc complex. The risc separated the two strands in the dsRNA. Now theres one strand on the risc. The loaded risk find target s(RNAs). Theres a transcript w a complementary sequence and it binds to the loaded risc strand. Then the fragments of the rna are reverse transcribed by rdrp.this rdrp reads rna, synthesizes rna

idk know this

How are flanking direct repeats created in transposition?

in transposition, staggered cuts are made in DNA and the transposable element inserts itself into the cut. later, replication of the single stranded pieces of DNA creates short repeats on either side of the inserted transposable element

positive snps may cause or not cause a problem?

may cause a problem

what changes chromatin configuration?

microRNA

are transposable elements good for you ?

no involved in -disease -aging -mutations

p elements use what to move around the host genome?

recombination

generation of antibody genes are assembled through:

recombination -cutting and pasting our DNA

what are the two types of transposable elements in eukaryotic cells?

retrotransposons and DNA transposons

transposable elements attract _____ and induce____

siRNA, methylation

Recombination

the genetic process by which one chromosome breaks off and attaches to another chromosome during reproductive cell division

true or false most transposable elements generate flanking direct repeats

true

true or false The traditional gene w regulatory sequence would have snps in the coding region (coding snp) that might change amino acid and make the protein lose its function

true

DNA transposons

"jumping genes" remove themselves from one place in the genome and move to a new site - cut and paste -forms a hair pin

what happens during recombination?

-alignment of two homologous DNA strands - precise breakage of each strand -equal exchange of DNA segments between the two strands -sealing of the resulting recombined DNA molecules through enzymes: ligases

would u expect transposable elements to be in a euchromatic part of the genome or the heterochromatic part?

-transposable elements generate flanking direct repeats on each side of the point of insertion into the target DNA -many transposable elemnts possess terminal inverted repeats -euchromatic bc there is repeats

what enzyme allows transposable elements to move around

-transposase -Enzyme that binds to the end of a transposon and catalyzes the movement of the transposon to another part of the genome by a cut and paste mechanism

transposable elements are highly mutagenic. why is this a problem?

Having a source of mutations isnt always a good thing but also its a source of variation in the genome

retrotransposons came from:

RNA viruses

terminal inverted repeats

Sequences found at both ends of a transposable element that are inverted complements of one another.

flanking direct repeats

Short, directly repeated sequence produced on either side of a transposable element when the element inserts into DNA.

Retrotransposons

Transposable elements that move within a genome by means of an RNA intermediate, a transcript of the retrotransposon DNA. - copy and paste

How do we know whether a specific disease has a genetic basis? a. Several relatives carry the same disease b. Identical twins share the disease less often than frternal twins c. Frequence of the disease is d. diff in diff environments e. None of the above

a. Several relatives carry the same disease

what may cause mutations to happen? a. all b. sunbathing c. errors in DNA replication d. transposable elemtents

a. all

Which of the following is true of a retrovirus, but NOT of the Alu retrotransposon? a. can be inserted into the genome b. encodes its own reverse transcriptase c. can be excised d. requires ccellular enzymes to make copies

b. encodes its own reverse transcriptase

How are TEs silenced?

by dsRNA amplification

micro rna act in the ____

cytoplasm

risc occurs in the___

cytoplasm

In humans and in chimpanzees, 99% of the Alu retrotransposons are in corresponding positions. Which of the following statements below is the most likely explanation for this similarity? a. The Alu retrotransposon is not capable of transposition in humans. b. The Alu retrotransposons are in the most beneficial position in the genome for primates. c. The Alu retrotransposons must also be in the same position in flies. d. Most of the Alu sequences in the chimpanzee genome underwent duplication and divergence before humans and chimpanzees diverged.

d. Most of the Alu sequences in the chimpanzee genome underwent duplication and divergence before humans and chimpanzees diverged.

what is the most abundant transposable element in the human genome?

Alu

What is an SNP (single nucleotide polymorphism)?

Are the most common type of genetic variation among people. Represents a difference in a single DNA building block, called a nucleotide -Changes in the dna that are not pathogenic and cause a condition but they associate w a specific phenotype

Two classes of transposable elements

Class I: retrotransposons Class II: DNA transposons

transposase

Cuts DNA backbone, leaving single-stranded "sticky ends"

Recombinant DNA

DNA produced by combining DNA from different sources

transposable elements (transposons)

DNA segments that can excise themselves from a chromosome and reinsert themselves at another location - jumping genes able to move to another position on a chromosome

DNA transposons came from:

DNA viruses