How DNA forms Chromosomes and other important information

Question 1

purines

Answer 1

double rings such as Adenine Guanine

Question 2

Pyrimidine

Answer 2

single ring thymine cytosine

Question 3

what is a Glycosyl

Answer 3

A glycosidic bond exists in the DNA molecule between sugar and nitrogen base.

Question 4

Chromatin consists of approximately ___ protein and ___ DNA

Answer 4

60% and 40%

Question 5

a chromosome is a long strand of ____ and ______ made of _______ nucleotides

Answer 5

DNA and Protein and 300 million

Question 6

how are chromosomes organized

what is a nucleosome

how is the DNA double helix strand strongly attracted to the histones

what do series of nucleosomes do

and what happens after

Answer 6

so the DNA is coiled to fit inside nucleus and every 200 nucleotides the DNA double strand is coiled around a central histone ( 8 histones together) and is held by another histone (Hi)

nucleosomes are complex of histones coiled by DNA

it has a negative charge and therefore meaning histones have positive charges

series of nucleosomes coil into chromatin fibres

chromatin fibres fold and supercoil

Question 7

humans contain how many of what chromosomes

Answer 7

46 ( 44 somatic, 2 are sex chromosomes)

Question 8

how many genes exist within the human genome

Answer 8

42 000 and 95+ is noncoding

Question 9

what are VNTR’s (variable number tandem repeats) and where can they be located

and what are they also known as

Answer 9

VNTR’s are sequences of base pairs that repeat, the length varies as does their position within the genome

you can find them in noncoding regions

also known as microsatelites

Question 10

what are introns and exons

Answer 10

introns are sequences of DNA removed from the mRNA transcript
and do not code for a protein

exons are genes which do encode the amino acid sequence for protein production

Question 11

what is a telomere

Answer 11

long sequences of repetitive noncoding DNA are found at the ends of chromosomes, called telomeres, to serve and protect DNA from losing nucleotides during replication

Question 12

what is the monomer of DNA

Answer 12

Nucleotide

but can also be polymers when joined together

Question 13

why is DNA called deoxyribonucleic acid instead of ribonucleic acid

Answer 13

because there is no oxygen at the second carbon of deoxyribose sugar

Question 14

what is the bond name that attaches the rungs of the ladder to the sides of the ladder

Answer 14

glycosyl bonds as it is between deoxyribose sugar and nitrogenous base