Chapter 10 Cell Reproduction

cell cycle

represents the continuity of life based upon the reproduction of cells

cell division

how do unicellular organisms reproduce?

development from a fertilized cell, growth, and repair

multicellular organisms depend on cell division for:

cell division

integral part of the cell cycle but not the only part

results in genetically identical daughter cells by duplicating genetic material

genome

a cell’s endowment of DNA/a cells genetic information

chromosomes

a high concentration of DNA molecules in a cell

chromatin

a complex of DNA and protein that condenses during cell division

contains histones

somatic cells

body cells that have two sets of chromosomes (ex: liver cells, skin cells, kidney cells)

gametes

sex cells with one set of chromosomes

cell division preparation

DNA is replicated and the chromosomes condense into sister chromatids

centromere

a structure that connects the two sister chromatids together (NOT ALWAYS in the center)

mitosis

the division of the nucleus

cytokinesis

division of the cytoplasm

meiosis

sex cells that are produced after a reduction in chromosome number

mitotic phase

the phase made up of mitosis and cytokinesis

alternates with interphase in the cell cycle

interphase phases

1) G1

2) S

3) G2

prophase, prometaphase, metaphase, anaphase, telophase

5 phases of mitosis

G2 of interphase

chromosomes are found in a nucleolus and replicated but decondensed

prophase

asters start to form from the centrosomes and slowly move to opposing poles in the cell

nucleolus disappears

nuclear envelop slowly dissolves

chromosomes condense

prometaphase

chromosomes are attached to kinetochore microtubules but not quite at the center of the cell

kinetochore microtubules

strands that attach to the kinetochore and centrosome — connect spindles to chromosomes

metaphase

chromosomes are lined up in the middle of the cell on the metaphase plate

anaphase

mitosis phase where daughter chromosomes move closer to their nearest aster

telophase and cytokinesis

a cleavage furrow appears between the two cells

a nucleolus and nuclear envelope forms for each set of cells’ genetic information

cells pinch off into new cells

mitotic spindle

apparatus of microtubules that controls chromosome movement during mitosis

arise from the centrosome and includes spindle microtubules and asters

tubulins

what are microtubules made of

microtubules (tubulin polymers)

hollow tubes made of proteins where the wall consists of 13 columns of tubulin molecules

centrosome

found in animal cells and assist with chromosome movement

two

how many sister chromatids does each duplicated chromosome contain

motor protein

protein powered by ATP that climbs up the microtubule to pull the sister chromatid towards the aster and breaks down the microtubule to be recycled later

motor protein method

what is the more common method of sister chromatid separation

cleavage

forming a cleavage furrow during cytokinesis

cell plate

structure that forms during cytokinesis in plant cells

prokaryotes (bacteris)

what kind of organisms don’t go through mitosis

binary fission

how do prokaryote (bacteria) reproduce

binary fission process

circular bacterial chromosome replicates and two daughter chromosomes actively move apart

septum forms and divides the cell

certain protists, diatoms, and yeasts

organisms that exhibit types of cell division that seem intermediate between binary fission and mitosis

help to support the idea that mitosis likely evolved from bacterial cell division

molecular control system

how is the cell cycle regulated