Chromosome structure
What type of DNA structure do eukaryotic chromosomes have (linear or circular)?
Linear
What protein does DNA wrap around
Histones
What does semiconservative replication mean?
One old strand, one new strand
Which enzyme makes RNA primers?
Primase
Are daughter cells identical or different?
identical
Where do spindle fibers attach?
Centromere (kinetochore)
How much does DNA shorten after wrapping around histones?
7x
What are replication forks?
Y-shaped regions where DNA is unwound
Which enzyme proofreads DNA?
DNA polymerase
What phase involves chromosome alignment?
Metaphase
What is the difference between euchromatin and heterochromatin?
Euchromatin = less condensed, active; Heterochromatin = condensed, inactive
What are radial loop domains?
Loops of DNA anchored to nuclear matrix
Why are Okazaki fragments formed?
DNA is antiparallel
Which enzyme prevents supercoiling ahead of the fork?
Topoisomerase
What ensures equal chromosome distribution?
Proper spindle attachment (M checkpoint too)
If DNA were not packaged efficiently, what physical problem would the cell face?
DNA wouldn’t fit inside the nucleus
If histones lost their positive charge, what would happen to DNA packaging?
DNA wouldn’t wrap properly
If hydrogen bonds were stronger, how would replication be affected?
If ligase is missing, what happens to the lagging strand?
Fragments remain unjoined
Predict the outcome of failed cytokinesis
One cell with two nuclei
How would constant heterochromatin formation affect gene expression long-term?
Reduced gene expression
Predict how increased histone binding would affect transcription
Decrease transcription
Why is replication faster in prokaryotes?
Smaller genome, less to replicate
if proofreading fails, what long-term effect occurs?
Mutations increase
How could errors in mitosis lead to cancer?
- what checkpoint?
Uncontrolled/abnormal division
- g1 checkpoint