Genes and Genetic Code

Question 1

what is DNA condensed into

Answer 1

chromosomes

Question 2

why must DNA be condensed into chromosomes

Answer 2

DNA molecules are incredibky long and must be tightly packed up to fit within the nucleus of a eukaryotic cell

Question 3

what type of proteins are DNA molecules wound around

Answer 3

histones

Question 4

what is it called when a DNA molecules is wound around a histone

Answer 4

a DNA-histone complex

Question 5

what do the DNA-histone complexes do

Answer 5

they coil further to form chromatin

Question 6

what does chromatin do

Answer 6

helps the DNA pack into chromosomes

Question 7

how many molecules of DNA does each chromosome contain

Answer 7

a single molecule

Question 9

where do prokaryotic cells store DNA

Answer 9

the cytoplasm

Question 10

where do eukaryotic cells store DNA

Answer 10

the nucleus

Question 11

what is the appearance of DNA in prokaryotes

Answer 11

they are shorter and circular

Question 12

what is the appearance of DNA in eukaryotic cells

Answer 12

long and linear

Question 13

does the DNA in prokaryotes associate with histones

Answer 13

no

Question 14

does the DNA in eukaryotes associate with histones

Answer 14

yes

Question 15

does the DNA in prokaryotes contain introns

Answer 15

no

Question 16

does the DNA in eukaryotes contain introns

Answer 16

yes they do

Question 17

what is a gene

Answer 17

a short section of DNA that codes for a polypeptide

Question 18

what is an exon

Answer 18

sections of DNA that do code for amino acids

Question 19

what is an intron

Answer 19

a section of DNA that does not code for amino acids

Question 20

what is a locus

Answer 20

the specific position along a chromosome that a gene is located at

Question 21

what is the genetic code

Answer 21

the sequence of bases that code for amino acids

Question 22

what is a tripet

Answer 22

a sequence of 3 amino acids

Question 23

what is each amino acid coded for by

Answer 23

a triplet

Question 24

what are the three features of the genetic code

Answer 24

• universal
• non-overlapping
• degenerate

Question 25

what does it mean by the genetic code is universal

Answer 25

each DNA triplet codes for the same amino acid in all organisms ( few minor exceptions)

Question 26

what does it mean by the genetic code is non-overlapping

Answer 26

each base in the DNA sequence is only read once

Question 27

what does it mean if the genetic code is degenerate

Answer 27

most amino acids are coded for by more than one triplet