introns and exons

Question 1

Exons?

Answer 1

Regions of DNA that code for proteins

Question 2

Introns?

Answer 2

Non coding DNA between exons

Question 3

RNA splicing?

Answer 3

Bc introns are within genes (between exons) they must be cut out of the mRNA before the mRNA leaves the nucleus.

Question 4

characteristics of introns

Answer 4

20-40 bases long generally
Mad up of short, 3-5 nucleotide long sequences that repeat

Question 5

Name for the short repeating nucleotide sequences of introns when in DNA

Answer 5

STR’s: Short Tandem Repeats

Question 6

Two other names for non coding DNA

Answer 6

introns or STR’s

Question 7

How do we get our STR patern

Answer 7

Each parental chromosome will give one specific length of STR to the child so the child also has 2 of each specific STR

Question 8

Why is STR used in genetic fingerprinting

Answer 8

The non coding DNA is very specific to individuals bc of the number of times that the lengths are repeated: alot of variation between people

Question 9

do prokaryotes have introns

Answer 9

no, only eukaryotes

Question 10

after what process does the RNA version of the DNA code become mRNA in eukaryotes?

Answer 10

After post trancriptional modification/ processing: RNA splicing

Question 11

Which enzyme removes the introns from the pre-mRNA

Answer 11

endonucleases

Question 12

Which enzyme splices (joins) the exons back together

Answer 12

ligases

Question 13

what are fragments of DNA called

Answer 13

okazaki fragments