BIOL 1190: Lab 2- Mitosis and Movement Across Cell Membranes

Stages of the cell cycle

interphase- cell grows in size, carries out its normal metabolic activities and prepares for cell division

cell division- events lead to production of 2 identical cells= daughter cells from original parent cell

phases of interphase

G1- cell grows and conducts normal cellular functions. prepares for cell division by duplicating most of organelles and other cytoplasmic materials

S phase- DNA is replicated

G2- enzymes and other proteins will aid in mitosis are produced, centriole replication is completed

what is mitosis

division of nuclear material (chromosomes/ DNA)

what is cytokinesis

division of cytoplasm and roganelles between 2 daughter cells

what happens in prophase of mitosis

- chromatin fibers condense into chromosomes

- centrioles pushes to opposite poles by lengthening microtubules

- spindle fibers form

what happens in metaphase of mitosis

- microtubules of spindle fibers align centromeres of each pair of chromatids at metaphase plate

what happens in anaphase of mitosis

- centromeres split and chromatids separate, move towards opposite poles

- chromatids now called chromosomes and appear V shaped

what happens in telophase of mitosis

- chromosomes are at poles and begin to uncoil into chromatin

- spindle breaks down

cytokinesis

- splitting/ moving

cleavage furrow

slight indent in plasma membrane

what is the role of microtubules in prophase

microtubules lengthen and push centrosome to pole (end of cells)

what is the role of microtubules in metaphase

microtubules align centrosome of chromatid pairs at mitotic spindle

what is the role of microtubules in anaphase

help chromosomes go to end of poles

what is one possible reason that chromatin fibers condense before dividing

- prevent long DNA strands from tangling

what types of cells enter the G0 phase

mature cells that dont need to divide anymore

what to look for in white fish mitosis in interphase

look for distinct nucleus with no chromosomes

what to look for in white fish mitosis in prophase

find disorganized but visible chromosomes with no nuclear membrane

what to look for in white fish mitosis in metaphase

chromosomes will be in single dark line, lined up on. metaphaseal plate

what to look for in white fish mitosis in anaphase

space between 2 lines of chromosomes, chromosomes may appear v shapes

telophase

visible cleavage furrow

-cells completes telophase will be slightly smaller, have a visible nucleus and be very close together

describe passive processes

- rely on brownian movement

- do not require additional energy from cell

describe active processes

- require energy ATP

- include active transport (primary and secondary) and vesicular transport

water movement in active transport

uses ATP to move water-soluble substances (like ions) low concen to high concen

water movement in passive processes

move molecules along the concentration gradient

describe vesicular transport

move molecules too large to pass through membrane channels

describe brownian motion

a passive process where small particles move randomly due to collisions with fast-moving molecules in a fluid (No ATP)

what happens when equilbrium is reached

- molecules will continue to move spontaneously with no net directional change

what is diffusion

movement of molecules from an area of high concentration of that molecule to area of lower concentration of that molecule

driving force of diffusion

kinetic energy

what one variable do you think causes one dye to diffuse a greater or lesser distance through the agar than the other dyes

-smaller particles will diffuse faster and further through the agar than the larger particles

define osmosis

type of simple diffusion

- net movement of water through a selectively permeable membrane from an area of lower solute concentration to area of higher solute concentration

when does osmosis happen

membrane is permeable to water but not to other substances

define solute

any substance that dissolves in another which forms solution

define solvent

substance the solute dissolves in

hypotonic solution

a solution with a lower concentration of solute is said to be hypotonic to the solution with the higher concentration of solute

hypertonic solution

A solution with more solute than a cell, causing water to move out of the cell by osmosis (RBC = crenation)

isotonic solution

2 solutions with equal solute concentrations

RBC description in isotonic solution

remains the same size and shape

- solution is isotonic to the cell

RBC description in hypotonic solution

water entering cell= causing burst= hemolysis

- solution is hypotonic to the cell

RBC description in hypertonic solution

water leave the cytosol and enter solution outside the cell

- cell crenates and appears shrivelled with spiked edges

- solution is hypertonic to the cell

EXPERIMENT: which of the 3 solutions was hypotonic to the RBCs

distilled water

EXPERIMENT: which of the solutions was hypertonic to the RBCs

3.0% NaCl

EXPERIMENT: which of the solutions was isotonic to the RBCs

0.9% NaCl

EXPERIMENT: which of the solutions caused the cells to crenate

3% NaCl

EXPERIMENT: which of the solutions caused the cells to hemolyze

distilled iwater

EXPERIMENT: in the substance starch, what colour is the control to give a positive result

dark blue/ black

EXPERIMENT: in the substance starch, what colour is the control to give a negative result

yellow

EXPERIMENT: in the substance chloride ions (NaCl), what colour is the control to give a positive result

cloudy

EXPERIMENT: in the substance chloride ions (NaCl), what colour is the control to give a negative result

clear

EXPERIMENT: in the substance glucose, what colour is the control to give a positive result

yellow- green or brown colour

EXPERIMENT: in the substance glucose), what colour is the control to give a negative result

light blue