Cell/Organism Reproduction Flashcards
Module 7
Cell division occurs for
growth
cell replacement
healing
reproduction
Prokaryotic cells divide by what process
binary fission
these cells divide by mitosis and cytokinesis
Eukaryotic cells
Tow main requirements for cell division
1.) 2 daughter cells must receive full complement of genetic material in the single parent cell
2.) the parent cell must be large enough to divide into two and still contribute sufficient cytoplasmic components to each daughter cell
What are the 6 steps in binary fission
1.) circular bacterial DNA molecule is attached by proteins to inner membrane
2.) DNA replication begins at the specific location and proceeds in 2 directions around the circle
3.) the new DNA molecule is also attached to the inner membrane near where the initial molecule attached
4.) as replication proceeds, the cell elongates symmetrically and separates the DNA attachment sites
5.) cell division begins with the synthesis of a new membrane and wall material at the midpoint
6.) continued synthesis completes the constriction and separates the daughter cells
What is the cell cycle for eukaryotes
1.) M phase
(mitosis and cytokinesis -> parent cell divides into two daughter cells)
2.) g1 phase (gap 1)
3.) s phase (dna synthesis)
4.) g2 phase (gap 2)
interphase is the time between two M phases (therefore from g1-g2)
how long does interphase last for
10-14 hours
What happens during interphase?
preparations for cell division
the number and shapes of chromosomes representative of a species is called its
karyotype
T/F most humans have 46 chromosomes (23 pairs)
true
How many pairs of sex chromosomes are in the human body
1
During the s phase, centromeres become
sister chromatids
what are the 5 stages of mitosis
1.) prophase
- chromosomes condense.
- centrosomes radiate microtubules and migrate to opposite poles
2.) Premetaphase
- microtubules of the mitotic spindle attach to the chromosomes
3.) Metaphase
- chromosomes align in the center of the cell
4.) Anaphase
- sister chromatids separate (becoming individual chromosomes) and travel to opposite poles
5.) telophase
- nuclear envelope re-forms and chromosomes decondense
Meiotic cell division results in how many daughter cells
4
What are the 5 stages of meiosis 1
1.) chromosomes become visible
2.) homologous chromosomes continue to condense and undergo synapsis
3.) once synapsis is done, each pair of homologous chromosomes form a bivalent. each chromosomes consists of 2 sister chromatids
4.) the chromosomes continue to shorten and thicken
5.) the nuclear envelope begins to break down
