Week6 Flashcards
Purpose of the G1/S checkpoint?
evaluate cell health
Purpose of G2/M checkpoint?
DNA replication check
Purpose of Spindle checkpoint?
Ensure chromosomes are correctly attached
What type of protein holds sister chromatids together?
cohesion
When are sister chromatids broken apart?
Anaphase
What enzyme breaks down the cohesion bond in anaphase?
separase
Haploid definition
A cell with one set of chromosomes
Diploid definition
a cell with two sets of chromosomes
if it’s haploid number is 40, what is its diploid number?
80
is a homologous chromosome equivalent to a haploid or a diploid chromosome set?
Diploid
What is included in a diploid count?
all chromosomes
what do diploids have in common?
length, genes, location, same function
where do diploids differ?
nucleotide sequence, came from different parents
What happens during interphase S subphase
DNA replication
what direction does DNA replication go in?
5 to 3
what direction does transcription read in?
5 to 3
what direction does RNA transcription occur in?
3 to 5
What direction does a leading strand replicate?
3 to 5
what direction does a lagging strand replicate?
5 to 3
is a leading strand continuous or discontinous?
continuous
is a lagging strand continuous or dicontinuous
discontinuous
What does Helicase do at the beginning of DNA replication
unwinds the helix and separates strands
what does topoisomerase do at the beginning of DNA replication
helps maintain stability while the strand is unwound
What makes two homologous (same function chromosomes) duplicated?
they are connected
why are sister chromatids identical
Because they are a result of DNA replication (produced from the same chromosome)
why are homologous chromosomes not identical?
they are from different parent cells
What happens to the spindle in prophase?
tubulin becomes centralized
what is the building block for spindles
tubulin
what happens in prophase
chromosomes spread throughout cell
What happens with the spindle during metaphase?
attaches chromosomes to spindle
what happens during metaphase?
chromosomes become aligned in the middle of the cell (metaphase plate)
What happens during Anaphase?
sis chromatids separate and go to opposite sides (duplicated chromosomes become unduplicated)
what happens during telophase?
2 new daughter cells form
spindle starts to disintegrate
What does the kinetochore microtubule type in a spindle do?
directly connect chromosomes to centrosomes
what does the interpolar microtubule type in a spindle do?
help separate chromosomes & chromatids
what does the astral microtubule type in a spindle do?
provide support for centrosomes
What microtubule does anaphase A involve?
kinetochore
what microtubule does anaphase b involve
interpolar
What is transcription?
a process that reads a strand of DNA and produces a protein corresponding to that code
How much of DNA is read at a time in transcription?
section by section, one gene at a time
what happens when a gene is read in transcription?
it unwinds, is copied, then rewinds
