Lab: Microscope and Cells

Compound Light Microscope

Has two magnifying lenses: ocular and objective, uses light for viewing, most commonly used

Proper way to hold microscope

One hand on under base, one hand holding the arm, carry microscope close to your body

On/Off switch

Near light source

Magnification

Multiply Ocular and Objectives

Ocular Lens

Stays the same; 10x

Objective Lens

Changes magnification; 4x, 10x, 40x

Major Parts of the Cell

Cell membrane, Nucleus, and Cytoplasm

Cell Membrane

Boundary of the cell; transports particles in and out of cell

Nucleus

In the middle of the cell, control center, houses DNA

Cytoplasm

Space between DNA & membrane; holds organelles (where chemical reactions occur) & inclusions (stored material for cell)

Cell Cycle

Interphase (G1, S, G2), Mitosis, Cytokinesis

G1

Cell growth (2x) and metabolis

S

synthesis; replication of DNA

G2

additional growth, replication of all other internal components

G1 and G2 Checkpoints

Body stops cell cycle to examine cell and check for any mistakes

DNA Replication

Chromosome replicated, two chromatids bond and are held by centromere

Blastula

Ball of cells after fertilization

Prophase

Chromatin becomes visible, nuclear membrane disappears, spindle fibers form

Metaphase

Centrioles at poles, chromosomes lined up in the middle, spindle fibers attach to chromosome at centromere

Anaphase

Centromeres divide, chromosomes separate

Telophase

Nucleus reforms, spindle fibers disappear, cytokinesis begins

Cytokinesis

Produces two identical daughter cells

Mitosis

Two daughter cells, Identical to original cell, Growth and repair