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Understanding the structure of a muscle cell

Introduction to cell theory--the idea that 1) all living things are made of one or more cells, 2) cells are the basic unit of life and 3) all cells come from other cells. Explore the roles that Hooke, Leeuwenhoek and others played in developing cell theory.

Hooke and Leeuwenhoek were two of the first scientists to use microscopes to study the microscopic world of cells. Hooke coined the term "cell" after observing the tiny compartments in cork, while Leeuwenhoek discovered a variety of living creatures in pond water, blood, and other samples. They contributed to the cell theory by suggesting that cells are the fundamental units of life and structure, and that all living things consist of one or more cells that originate from other cells by division. 

All living things are made up of cells, which is the smallest unit that can be said to be alive. An organism may consist of one single cell (unicellular) or many different numbers and types of cells (multicellular).

Plant cells have a cell wall in addition to a cell membrane, whereas animal cells have only a cell membrane. Plants use cell walls to provide structure to the plant. Plant cells contain organelles called chloroplasts, while animal cells do not. Chloroplasts allow plants to make the food they need to live using photosynthesis.

Video 1: Construction of a circle when its radius is known
Video 2: Examples of how to construct a circle
Video 3: Common mistakes made when constructing a circle

Video 1: How to construct a line segment
Video 2: Examples of constructing different line segments
Video 3: Common mistakes made when constructing a line segment

Video 1: What are perpendiculars and perpendicular bisectors and how to construct them
Video 2: How to draw a perpendicular and perpendicular bisector using a ruler and a compass
Video 3: Examples related to the construction of perpendiculars and perpendicular bisectors on a line segment
Video 4: Common mistakes made when constructing perpendiculars and perpendicular bisectors

Video 1: How to construct a copy of an angle
Video 2:
Video 3: Common mistakes made when constructing an angle as a copy of another

Video 1: How to construct angles of a given measurement using paper and a protractor 
Video 2: How to construct angles of a given measurement using a compass
Video 3: Examples of constructing angles of specific measurements
Video 4: Common mistakes made when constructing angles of specific measurements

Introduction to the cell.