The unit of life- The cell

Cell

the basic structural, and functional unit of all living organisms.

Tissue

a group of similar cells working together to carry out a specific function

Organ

a group of different tissues working together to carry out a function.

system

a group of different organs working together to carry out many functions.

Cell continuity

states that all cells arise from pre-existing cells, through cell division.

unicellular organisms

perform all life functions in a single cell. cells are small has a short life span

multicellular organisms

Cells work together in tissues and organs. Can become large has a longer life span.

Light microscope

used to study living cells when low magnification and low resolution is enough

Electron microscope

use a beam of electrons and electromagnets to illuminate to focus and magnify the image. they provide higher magnification and higher resolution than a light microscope. there’s two types

Cytoplasm

jelly like material that contains dissolved nutrients and the salts plus structures called organelles where many of the chemical reactions happen. water content 70%-85%

Nucleus

contains genetic material which controls the cells activities

Cell membrane

controls the movement of substances in and out of the cell

Mitochondria

organelles that contain the enzymes for respiration , where most energy is released in respiration

Ribosomes

tiny non membranous organelle where protein synthesis occurs

Turgor pressure

outward pressure of a vacuole against the cell membrane and the cell wall, gives support to plant cells

chloroplast

organelles that contain the green pigment, chlorophyll which absorbs light energy for photosynthesis

Cell wall

made from cellulose, it strengthens the cell and supports the plant

Permanent vacuole

filled with cell sap to help keep the cell turgid

Eyepiece

where the specimen is viewed through, it magnifies the specimen

objective lens

Magnifies the specimen, low power, medium power and high power lens

Stage

holds the slide in place

Coarse focus wheel

Brings specimen into rough focus

fine course wheel

brings specimen into sharp focus

Light source

illuminates the specimen

Iris diaphragm

Controls the amount of light reaching the slide

Condenser

Gathers the light and focuses it on the specimen

Protoplasm

the total living content of a cell. which includes both the cytoplasm and the nucleus.

Cytosol

cytoplasm minus organelles

chromatin

precursor of chromosomes, visible when a cell is not dividing

DNA replication

DNA makes an exact copy of itself