Study Guide Flashcards
Phases of Mitosis
Prophase, Metaphase, Anaphase, Telophase. (PMAT)
Prophase
(pack) Chromosomes become visible, Centrioles move to opposite sides. Spindles form. Chromosomes attach to spindles at centromere. Nuclear membrane breaks down.
Metaphase
(Middle) Spindle fully formed. Chromosomes line up in middle of cell (meta plate). Microtubules attach to centromeres to keep chromosomes in middle of the cell.
Cytokinesis
After mitosis. Cytoplasm of the cell divides (rest of cell)
Telophase
(Two) Chromosomes reach opposite sides. The nuclear envelope forms. Spindle disappears. Chromosomes uncoil.
Anaphase
(Away) Sister chromatids move away from each other (X to > <)
Mitosis
The division of the cell nucleus
Cytokinesis (Plants)
Forms “Cell plate” and divides down the middle without cell shape change.
Why can’t a cell just keep growing larger rather than dividing?
surface area to volume ratio decreases, making it difficult to transport nutrients in and waste products out through the cell membrane,
Cytokinesis (Animals)
Forms “cleavage furrow” pinches in the middle of the cell to divide (think peanut)
Phases of Interphase
G1 phase, S phase, G2 phase.
G1 phase
cells increase in size, make new proteins and organelles
S phase
DNA synthesis
G2 phase
Makes new organelles. Checks that replication was successful
G0
Where cells go to die. Cells that are not actively dividing, or can not divide.
What kinds of cells go to G0?
nerve cells, heart muscle cells, tissues cells, brain cells (cells that can’t replicate), mutated cells
Function of Spindles
Pull apart the chromosomes to opposite ends of the cell.
How do organisms get bigger?
Cell divison
What are sister chromatids?
Identical copies of chromatids made during cell division
What is the end result of mitosis?
The division of the cell nucleus
How many chromosomes are in human somatic (body) cells?
46 chromosomes
What is the centromere?
Where the chromosomes attaches to the spindles
What is Chromatin?
The material DNA is made of. Loosely wound DNA around histone proteins.
What protein does DNA wrap around?
Histone proteins.
How can a body increase in size?
Cell growth and mitosis
What is a major problem if a cell is too large
effect of diffusion of materials across cell membrane is decreased
DNA is copied during what phase?
S phase.
What is the longest phase of the cell cycle
interphase
What is a homologous pair of chromosomes
same genes in the same order. (Identical) Not XY or XX
