chapter 6 Flashcards
What is the cell theory?
all cells come from preexisting cells
what is Virchow’s principle
cells come from cells
what are the two kinds of reproduction?
asexual and sexual
what is asexual reproduction
copying the parent genes identically
what is sexual reproduction
sperm and egg
what is a binary fusion
binary fusion is splitting up the cell
What are the two events in the cell cycle?
interphase and mitotic phase
What is interphase and what does it consist of?
interphase is the duplication of cells; G1, S, G2
G1:
S:
G2:
G1: Growth (increase in the cytoplasm)
S: Duplication of chromosomes
G2: Growth (preparing for division)
What is the mitotic phase what does it consist of?
division of cells; mitosis and cytokinesis
Mitosis:
Cytokinesis:
Mitosis: Division in the nucleus
Cytokinesis: Division in the cytoplasm
What are eukaryotic chromosomes made of?
chromatin that is later compacted while preparing for divison
what is chromatin made of?
dna and protein
where are chromosomes duplicated?
s phase
what are karyotypes
the visual appearance of chromosomes
What does each chromosome appear as?
two identical sister chromatids
Where are the sister chromatids joined?
the centromere
What is mitosis and when does it take place
nuclear division that takes place during the duplication of chromosomes that is joined into sister chromatids. Later it is split and chromosomes are distributed into daughter cells.
interphase
division of the nucleus
prophase
chromosome condenses and becomes visible; nucleus disappears
prometaphase
chromosomes continue to condense
metaphase
meet at metaphase plate in the middle, sister chromatids attached to spindle fibers
anaphase
sister chromatid (now chromosomes) breaks down and is pulled towards opposite ends
telophase
chromosomes arrive at opposite ends and starts to decondenses, nuclear envelope surrounds each set of chromosome
cytokinesis (animal cell and plant cell)
animal cell: cleavage furrow separates the daughter cell
plant cell: cell plate separates the daughter cells
cells that are not preparing to divide are called…
G0
What happens if G0 doesn’t go into G1
it remains there forever; not dead but not dividing
G1 checkpoint-
allows to enter to S phase or go into G0
G2 checkpoint-
proper chromosome duplication is assessed
M checkpoint-
attachment of each kinetochore to a spindle fiber