BIO 340: Genetics Exam III (Mangone) 118
Q&A/ Already Graded A+.
What is a gene? - Answer: Fundamental unit of inheritance
Origin of the word "gene" - Answer: greek: genos (origin), and genesis (birth)
Gregor Mendel Experiment - Answer: -pea plants
-traits do not blend in offspring
-traits are discreet, distinct entities
Prokaryotic DNA Replication - Answer: -has single origin (OriC)
-is bidirectional
-replication fork
-draw out diagram for 5', 3' directionality
Eukaryotic DNA replication is similar except: - Answer: -has multiple origins of replication
, Page 2 of 15
-more DNA
-chromosomes are linear
-RNA is complexed with proteins
Telomerase - Answer: counteracts shortening of DNA by adding repeated segments of DNA to
ends of eukaryotic chromosomes
apoptosis - Answer: -when a cell tells itself to stop dividing
-can happen with telomeres become to short despite counteraction of telomerase
Length of human DNA - Answer: 2.3 m (~7.5 ft)
Chromatin - Answer: condensed nucleoprotein, usual state of DNA
euchromatin - Answer: gene expression, uncoiled and active
heterochromatin - Answer: inactive b/c lack or have unexpressed genes
-contains both telomere and centromere
Orders and Size of Chromatin - Answer: 1. DNA double helix (2 nm)
2. Bead and String formation around histones (11 nm)
3. Chromatin packed nucleosomes (30 nm)
4. extended section of chromosome (300 nm)
5. condensed section of chromosome (700 nm)
6. metaphase chromosome (1400 nm)
"Beads on String" - Answer: to form chromatin, HI histone
Human domain - Answer: contains 2,000 looped domains