Bio Unit 6.5 Flashcards - Mitosis + Stem Cells

What’s the difference between chromatin and chromosomes?

Choromatin is losely coiled, dissolved dna which you cant see with microsopes. It’s present in inter[has. genes are expressed meaning that they take the form of proteins

Chromosomes are tightly coiled and made up of sister chromatids. They are present in the m phase and genes are not expressed.

What are chromatids

The sister chromatin which come together to make up chromosomes

What happens in prophase

• at the start of prophase

  • dissolve nuclear membrane, centrosomes move to either side, spindleds form, chromatin condenses

• at the end of prophase

  • membrane fully dissolved centrosmes are on either side, spindles have formed, chromatin has condensed into X shaped chromosomes made up of sister chromatids

NCSC: cncs.

What is a centrosome?

The region containing centrioles

What is a centriole?

Barrel proteins which send out the sppindle fibers

What is a aster?

the censtrosome sending out the spindles

What is a centromere

The center of the chromsome/chromatin which the spindle fibers attach to

What are the two types of cytokinesis

Animal (cleavage furrow) and plant (cell plate)

What is cytokinesis

the division of the cytoplasm

What happens in animal cells during cytokinesis

A cleavage furrow where the cell is pinching itself

What happens in plant cells during cytokinesis

You get a cell plate (forming a new dividing cell wall)

How do you do image questions of what phase of mitosis is it?

• check: are X’s lined up the middle? (if yes, metaphase)

• Are halves of x’s being pulled apart from the middle by spindle? (if yes, anaphase)

• Is there two nuclei? if yes, telophase

What is replication in prokaryotes called and how does it work?

BINARY FISSION:

• replication in prokaryotes, mitochondria, and chloroplast

• 1 circle chromosome is replicated and pinched (literally just a circle, has a line through it and grows, then the line divides it fully.

What is metaphase

Chromosomes are pulled to a line in the middle

Here is the M checkpoint (are the spindles attached properly?)

What is anaphase?

pulling apart the chromosomes to either side of the cell. DNA replication already happened in the S phase so you have double everything that you need, so when pulled apart there is an equally exact copy of chromosomes on either side

What is telophase?

Prophase in reverse:

• nuclear membranes created once again

• centrosomes are move to center, spindles dissolve, revert back to chromatin

What are the 3 types of potents?

Totipotent, pluripotent, multipotent

What is totipotent? embryonic or adult?

Can become every cell including placenta, embryonic

toti = tutti = EVERYONE/EVEYRTHING

What is pluripotent? embryonic or adult?

can become every adult cell, embryonic

pluri = curry (full of dead things = adult cells)

What is multipotent? embryonic or adult?

can only become a small subset of cell types: adult cell.