(P) Lesson 2: Human Chromosome Flashcards
macromolecules that carry genes
Chromosome
composition of Chromosome
DNA
T or F. Chromosome is long, thin, fragile, that doesn’t necessarily needs to be packaged
F (needs to be packaged to avoid breaking)
cycle of events that lead to the production of 2 daughter cells via cell division
Cell cycle
Phase: cell is not undergoing cell division yet, it is only preparing for it
INTERphase
Phase: the cells are resting but metabolically active
G0
Phase: The cell is planning to divide which prepares for the replication of DNA
G1
Phase: replication and synthesis of DNA
S
Phase: preparation towards mitotic division
G2
T or F. In G1 phase, the chromosome is now 2 double-stranded DNA molecules (aka dyad) and held together by a centromere.
F (G2)
Chromosome w/ one DNA is called?
monad or one chromatid
single DNA that has replicated is now called?
dyad or 2 sister chromatids
How to make the DNA compact?
needs to associate with histones
T or F. An archea’s DNA can only be compact when it is associated with proteins called histones
F (histones are not present in prokaryotes)
This are proteins rich in positively (+) charged lysine and arginine residues which bind to the negatively (-) charged phosphates (PO4) of DNA
Histones
What are the residues/amino acids present in histones?
lysine and arginine
T or F. Non-histone proteins are involves in transcription factors and chromosome packing.
F (transcription factors only)
regulates the transcription of a gene
non-histones
T or F. Histones regulates which part of the DNA will be transcribed after associating with the promoter sites of the gene
F (non-histone)
At what phase where we’ll be able to see a dyad?
Metaphase
lowest level in chromosome packing
nucleosome
How many base pairs of DNA wrapped 1 and 3/4 times around a core of 8 histone proteins?
150
nucleosomes coil into 30nm?
chromatin fiber
T or F. The chromatin fiber exists even during interphase although not very visible under a microscope.
T
during division, the chromatin fibers are attached in loops of variable size to a?
protein scaffold
T or F. Further coiling yields the most compact structure that is seen during the telophase.
F (metaphase)
our 2 chromosomes are derived from?
1 from the father and 1 from the mother
T or F. The homologous pair have similar DNA sequences with slight variation (not identical).
T
Chromatids that have similar DNA sequences with slight variation (not identical)
Homologous pair
chromatids formed during the?
S phase
→ they have genetically-identical DNA sequences
sister chromatids
chromatids from different homologs; not generally-identical
non-sister chromatids
short-arm of the chromosome
P (etit)
long-arm of the chromosome
Q (ueue)
divides the chromosome into the 2 arms
Cen (tromere)