Chapter Summary 2.1. 2.2

Chapter 2 Summary - Fatima Syeda

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Chapter 2 - Summary

Cells (binary/octet-stream)

Caption: : Cells

Cells are the smallest living Units of an organism. All cells have three​​​​​​​ things in common no matter what type of cell they are, all cells have a cell membrane which separates the inside of the cell from it's environment, cytoplasm, the jelly like substance within a cell and DNA which is the cell's genetic material.

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Microscopes

Very small things need to be magnified or made bigger so that they become visible to us. Scientists use microscopes to do this.  Objects that an only be seen through a microscope are described as microscopic. Microscopes allow scientists to see the tiny building blocks of life, cells. The magnification of a microscope tells you how much bigger the image is than the real object. A micrometre is often used by scientists to measure microscopic things, a micrometre is one thousandth of a millimetre. 

Light Microscope (binary/octet-stream)

Light microscope

The type of microscope used in many schools and laboratories is a light microscope. Light from a mirror or a lamp passes through a specimen  or object. The specimen being looked at must be very thin so light can pass through easily. The light then passes through a series of lenses that causes the specimen to appear bigger. What you see through the microscope is called the image.   

Stereo and Electron microscopes

Stereo Microscope Using a stereo microscope is like having two monocular microscopes joined together, with each one focusing on the same point but from different angles.The image you see is in three dimensions.

Electron Microscope Electron microscopes use beams of tiny particles called electrons instead of light and are able to magnify up to a million times! There are two types of electron microscopes.. SEM (scanning electron microscope) TEM (transmission electron microscope)

Cells

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The work of different people and discoveries led to the development of the cell theory, which explains the relationship between cells and living things. all living things are made up of one or more cells Cells are the basic building blocks of all living things new cells are produced from existing cells

Animal cells

Animal Cell (binary/octet-stream)

Animal cells contain smaller cells called organelles. Each organelle has a special job or function. Some organelles are too small to be seen with a light microscope and are only visible with an electron microscope.Examples are: mitochondria- the powerhouse of the cell  lysosomes- the garbage disposal units  endoplasmic reticulum- forms pathways that allow materials to move quickly and easily through the cell ribosomes- microscopic 'factories' that produce proteins  

Plant cells

Plant Cell (binary/octet-stream)

Like animal cells, plant cells have a cell membrane , cytoplasm and nucleus. The vacuole in a plant cell is much larger than the one in an animal cell. Plant cells also have a cell wall outside the cell membrane. The cell wall helps support the plant and gives it shape. Many plants cells contain chloroplasts, chloroplasts contain a green substance called chlorophyll and are found in the green parts of plants. Plants can't go hunting for food so they make their own food using photosynthesis. 

Fungal cells.

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Fungi are organisms that can be made of just a single cell or many cells. Yeast is an example of a single-celled fungus, while the toadstool is an example of a fungus with many cells. Cells of fungi have the same structures as animal cells plus a cell wall like plant cells. Fungal cells do not have chloroplasts; therefore can't make their own food. Fungi produce and release chemicals that digest the material they are growing on.

Dividing cells

Mitosis (binary/octet-stream)

Unicellular organisms reproduce by dividing to produce two new identical cells. Mitosis is when a cell divides into two identical cells. Mitosis helps for repair, cells in multicellular organisms often wear out or are damaged and need to be replaced. For example, each time you cut yourself or scrape some skin off, the damage is repaired by mitosis producing new cells.

Happy Studying :)

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