CELL THEORYCELLS AND MICROORGANISMS

Compare the characteristics of living and non-living things.

Understand that living things are made up of one or morecells.

Know that cells:• are the structural and functional units of life• come from pre-existing cells• contain hereditary material

The cell membrane defines a cell; it separates the cell fromits surroundings.

Overview

What makes something living?

Work in small groups to create a list of requirements to classify something as living or non-living.

Activity

Earth is the only known planet that sustains life.

“Life” refers to the vast diversity of living things which inhabitthe planet.

Biology is the study of living things!

Living and Non-Living Things

Living things must show all of the following characteristics:

MOVEMENT

RESPIRATION (energy production)

SENSITIVITY (detecting and responding to changes)

GROWTH (the ability to make more cells)

REPRODUCTION (the ability to pass on genetic info)

EXCRETION (removal of wastes)

NUTRITION (take in and use appropriate nutrients)

Living Things

INTENDED STUDENT LEARNING

Compare the characteristics of living and non-living things.

INTENDED STUDENT LEARNING

Compare the characteristics of living and non-living things.

Complete the following table to show why each of these organisms is considered to be alive.

Activity

Living? Picture Movement Respiration Sensitivity Growth Reproduction Excretion Nutrients

Koala

Whale Shark

Tree

Euglena

Complete the workbook questions in your books.

Questions

A theory starts as a hypothesis. If there is enough evidence tosupport the hypothesis it becomes a theory - an accepted andvalid explanation.

The Cell Theory describes the properties of cells.

Cell Theory

Robert Hooke was the first to describe the cell, and publishedhis observations in his book, Micrographia, in 1670.

Hooke sliced a piece of cork and noticed the structural unitsunder his microscope.

He called these structures ‘cells’ (small rooms).

Cell Theory

Leeuwenhoek (1674) was the first to observe live cells,including red blood cells.

Cell Theory

The Cell Theory states:• All living organisms are composed of one or more cells.• The cell is the basic structural and functional unit of life.• All cells arise from pre-existing cells by cell division.

Modern Cell Theory added more points after advancement incytology and molecular biology:

• There is a flow of energy in cells.• The cell contains hereditary information (DNA) which is passed on

during cell division.• All cells are basically the same in chemical composition (molecules,

ions, and atoms).

Cell Theory

Cell History

INTENDED STUDENT LEARNING

Understand that living things are made up of one or more cells.

INTENDED STUDENT LEARNING

Know that cells:• are the structural and functional units of life• come from pre-existing cells• contain hereditary material

The cell membrane is responsible for controlling what entersand exits the cell. It is approximately 8 nanometres thick.

The membrane is comprised of a phospholipid bilayer and isimportant in maintaining the internal environment of a cell. Ifthere was no control over the environment, the cell would diequickly.

The Cell Membrane

Fluid Mosaic Model

INTENDED STUDENT LEARNING

The cell membrane defines a cell; it separates the cell from its surroundings.

Homework

Independent content revision

Workbook questions