1. Alberts • Bray • Hopkin • Johnson • Lewis • Raff • Roberts • Walter
Essential
Cell Biology
FOURTH EDITION
Chapter 5
DNA and Chromosomes
Copyright © Garland Science 2014

2. Microscopy revealed chromosome bodies that
are segregated to daughter cells during cell division.
Fig. 5-1

3. T. H. Morgan used Drosophila genetics and the giant
chromosomes from their salivary glands to show
that chromosomes contain the genetic information.
-1920s
Drosophila genetics
Giant polytene chromosomes
In larval salivary glands

5. Genetic Information for Virulence
DNA Component of Chromosomes Contains
Genetic Information for Virulence
Purified DNA (not
protein) from
heat-killed S strain
also transformed.
Fig. 5-3

6. Genetic Information for Bacteriovirus
DNA Component of Chromosomes Contains
Genetic Information for Bacteriovirus
Fig. 5-5

7. Watson and Crick Determined Structure of DNA in 1950s
four different
deoxyribonucleotide
building blocks
right-handed
double helix
complementary
base pairing
Fig. 5-2

8. Complementary Base Pairing
Fig. 5-6

9. Like many others, DNA is a linear code:
Fig. 5-8

10. Linear Code of DNA decoded into linear array
of amino acids in protein (w/ RNA as intermediate).
Fig. 5-9

11. Double-stranded character of DNA immediately
suggested a mechanism for heredity.
Each strand provides a template for
duplicating the DNA before cell division.
Fig. 5-14

12. Specialized Chromosome Regions Are Needed
for Replication and Segregation During Mitosis
Fig. 5-15

13. Most of the DNA Decondenses During Interphase
stays condensed
The decondensed
DNA is called
euchromatin.
Fig. 5-18

14. Heterochromatin Flanks Two Specialized Regions
Needed for Chromosome Segregation
also regulates
expression of
some genes
Fig. 5-28

15. DNA is Packaged with Proteins in Chromosomes
Electron Microscopy
Fig. 5-24

16. X-Ray Crystal Structure
of Nucleosome
Fig. 5-22

17. Histone H1 Alters Path of Linker DNA,
Allowing Further Compaction to 30 nm Fiber
Fig. 5-23

18. ATP-Dependent Nucleosome Plows Loosen Chromatin for Gene Expression
Fig. 5-26

19. Covalent Modifications on Histone N-Terminal Tails
Also Affect Chromatin Structure
Fig. 5-27

20. N-Terminal Modifications Provide a Histone Code
Fig. 5-27
modifications allow binding
of non-histone chromatin proteins

21. Heterochromatin Assembly Involves
Binding of HP1 to H3-MeK9
H3-MeK9
& HP1
Fig. 5-26

22. Heterochromatin is a Heritable Inactive Chromatin State
Epigenetic:
heritable state
that acts above
the level of
gene sequence
Fig. 5-30