Lecture 1 Introduction

Question 1

What is the difference between a nucleoside and a nucleotide?

Answer 1

Nucleoside is a sugar and base whereas nucleotide us a sugar, base and phosphate

Question 2

Which confirmation does double stranded DNA most frequently take?

Answer 2

B-DNA

Question 3

What is the bond holding the sugar and phosphate in a nucleotide called?

Answer 3

Phosphoester bond

Question 4

What type of interactions occur between stacked bases in the DNA double helix and helps stabilize the helix?

Answer 4

Van der Waals forces

Question 5

What is NOT a difference between DNA and RNA?

Answer 5

RNA bases include two purines and two pyrimidines, while DNA bases include two purines and three pyrimidines

Question 6

In DNA which base pairings normally occurs between 2 strands of DNA?

Answer 6

A-T and C-G

Question 7

The level of DNA packaging brought about by the formation of _____ looks like beads on a string

Answer 7

Nucleosomes with linker DNA between them

Question 8

What are differences between euchromatin and heterochromatin?

Answer 8

Euchromatin is transcriptionally active, lightly stained and mainly found during interphase
Heterochromatin is found towards the periphery of the nucleus during interphase and the centromeres and telomeres of chromosomes, its transcriptionally inactive and heavily stained

Question 9

Condensed chromatin is…

Answer 9

associated with low levels of gene expression

Question 10

Histones are…

Answer 10

proteins around which the DNA is wound approximately 2 times

Question 11

What is the histone octamer complex consisting of?

Answer 11

8 positively charged histone proteins (two of each H2A, H2B, H3, H4) that aid in the packing of DNA

Question 12

What is the eukaryotic chromosomes level of compression?

Answer 12

1400nm