Science 8 Unit 2 Topics 1-3
cell theory
All living things are composed of one or more cells, Cells are the basic unit of structure and function in all organisms.
Level of Cell Organization
System ➔ Organ ➔ Tissue ➔ Cell
Why are cells so small
They would be very inefficient if they were large. Larger cells would need more materials and would produce more waste.
Cell Wall
a rigid structure surrounding the cell membrane of plants, fungi, and some unicellular organisms; protects and supports the cell
Organelles
a structure within a cell that has specific function
eyepiece
also called the ocular lens - used to look through, and the lens magnifies an object
Chloroplasts
an organelle that contains chlorophyll and enables plants to make carbohydrates through the process of photosynthesis; found only in plants and in some unicellular organisms
characteristics of all living organisms
are made of cells need energy grow and develop respond to their environment reproduce have adaptations for their environment produce wastes
functions all living organisms
energy movement reproduction growth wastes
Unicellular
having a single cell
Multicellular
having many cells
Vacuoles
in a cell, a fluid-filled organelle that stores water, food, wastes, and other materials
Nucleus
in a cell, an organelle that controls all the cell's activities
field of view
is the area you see when you look through a microscope
coarse adjustment knob
moves the tube up and down, to help focus the lens - like a camera lens
Cytoplasm
the gel-like substance within the cell membrane that contains and supports the structures of the cell
Cell Membrane
the selectively permeable structure enclosing the contents of a cell or organelle; regulates the passage of substances into and out of a cell or organelle
Cellulose
the tough, carbohydrate material that in large part makes up the cell walls of many plants and fungi
the diaphragm
use to change the amount of light that shines on the slide
the stage
where you place the slide; it has clips so the side doesn't move and it has a hole in the center which allows a light to brighten up the slide