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48 Cards in this Set

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  • Back
a nonliving particle consisting of a core of hereditary material surrounded by a protein coat
Characteristics of Viruses
1) They appear to be neither living nor nonliving
2) They can reproduce only inside of a living cell
Classification of Viruses
They are classified by their shape, the kind of hereditary material they have, the kind of organism that they infect, and their method of reproduction.
Host Cell
A virus has to be inside of a living cell to reproduce. The cell in which a virus reproduces is called a host cell.
What are the two ways that a virus acts in a host cell?
1) It can be active
2) I can become latent and be an inactive part of the cell for a while
Active Viruses
An active virus causes the cell to make new viruses, which destroy the host cell.
What are the steps that an active virus takes to reproduce itself inside a bacterial cell?
Attach, invade, copy, and release.
Latent Viruses
They enter a cell and becomes part of the cell's hereditary material without immediately destroying the cell or making new viruses. They may hide inside host cells for many years and then at any time become active.
It is made from damaged virus particles that can't cause disease anymore. It could prevent some viral diseases.
Viral Diseases
Viruses may cause disease in plants, animals, fungi, bacteria, and protists. There are no antibiotic medications to CURE viral diseases.
Gene Therapy (helpful viruses)
It involves substituting correctly coded hereditary material for a cell's incorrect hereditary material. Correctly coded hereditary material is enclosed in a virus. The virus may the "infect" defective cell, taking the new strand of hereditary material into such cells to replace the incorrect hereditary material.
Human Immunodeficiency virus attacks the body's immune system. It causes a disease called AIDS, or acquired immune deficiency syndrome.
It stands for Acquired Immune Deficiency Syndrome. AIDS allows the body to be infected by many organisms that cause disease.
Compound Light Microscope
The microscope used in studying life science. It lets light pass through an object and then through two or more lenses. It magnifies organisms or parts of organisms, making details of structures visible.
Electron Microscope
It uses a magnetic field to bend beams of electrons. It can magnify images up to 1,000,000 times.
Who is Rober Hooke?
He was an English scientist. In 1665, Hooke made a very thin slice of cork and looked at it under his microscope. The cork seemed to him to be made up of little empty boxes, which he called CELLS.
The Cell Theory
1) All organisms are made up of one or more cells
2) Cells are the basic units of structure and function in all organisms
3) All cells come from cells that already exist
Two Basic Types of Cells:
Prokaryotic Cell
Cells that have no membrane around their nuclear material are prokaryotic cells. (e.g. Bacteria and cells that form pond scum)
Two Basic Types of Cells:
Eukaryotic Cell
A cell that has a nucleus with a membrane around it is a eukaryotic cell. (e.g. the animal and plant cells)
Cell Membrane
It is a structure that forms the outer boundary of the cell and allows only certain materials to move into and out of the cell. It made up of a double layer of fats with some proteins scattered throughtout.
The function of cell membrane
It helps to maintain a chemical balance between materials inside and outside the cell. Food and oxygen move into the cell through the membrane. Waste products leave through the membrane.
The largest organelle in the cytoplasm of a eukaryotic cell is the nucleus, a stuture that directs all the activities of the cell
The nucleus contains genetic blueprints for the operations of the cell in the form of long strands called chromatin, a form of hereditary material.
DNA is the chemical that controls the activities of the cell.
Cytoplasm is the gel-like material inside the cell membrane and outside the nucleus. It contains a large amount of water and many chemicals and structures that carry out the life processes in the cell.
The structures within the cytoplasm of eukaryotic cells are organelles. Each one has a specific job or jobs.
Endoplasmic Reticulum (ER)
ER is a folded membrane that move materials around in the cell. It extends from the nucleus to the cell membrane and takes up quite a lot of space in some cells.
Cells make their own proteins on small structures in the cytoplasm called ribosomes.
Golgi Bodies
In cells, structures called Golgi bodies are stacks of membrane-covered sacs that package and move proteins to the outside of the cell.
(Powerhouses of the cell)
Cells require a continuous supply of energy. Mitochondria are organelles where food molecules are broke down and energy is released.
In the cytoplasm, organelles called lysosomes contain chemicals that digest wastes and worn-out cell parts as well as break down food.
Cell Wall
It is a rigid structure outside the cell membrane that supports and protects the plant cell.
What are the major differences between an animal cell and a plant cell?
The major difference is that plant cells have cell walls.
Plant cells also differ from animal cells because they can make their own food.
They are organelles in plant cells in which light energy is changed into chemical energy in the form of a sugar.
It is one of the chemicals in chloroplasts that traps light energy. It is a green pigment.
Bacterial Cells
Bacterial cells are prokaryotic cells. Such a cell has a cell wall and cytoplasm, but it has only a single chromosome. There are no nuclei or membrane-covered organelles in bacteria, but they do contain ribosomes.
How cells differ?
Cells comes in variety of sizes, shapes, and functions.
In many-celled organisms, cells are organized into tissues, which are groups of similar cells that do the same sort of work.
Different tissues are further organized into organs, which is a structure made up of different types of tissues that work together to do a particular job to keep an organism alive.
The first compound microscope
Janssen made the first compound microscope in 1590. Leeuwnhoek used fine lenses to make accurate observations. Hooke, Schleiden, & Schwann all drew their conclusions about cells with the help of the microscope.
What is the difference between compound light microscopes and electron microscopes?
Compound light microscopes use light and lenses to make images, while electron microscopes bend beams of electrons in a magnetic field.
How do cells function?
Cell functions are performed by organelles under control of DNA in the nucleus.
Examples of Viral Diseases in humans
AIDS, measles, polio, chichen pox, influenza or flu, mumps, rabies, common cold
Transmission Electron Microscope (TEM)
One kind of electron microscope, which is used to study parts inside a cell. The object has to be sliced very thin and placed in a vacuum. There is no air in a vacuum. Therefore, only dead cells and tissues can be observed this way.
Stereo Microscope
Stereoscopic light microscope that gives you a three-dimensional view of an object. They are used to look at thick structures that light can't pass through.
What packages and secretes substance?
Structures in cells called Golgi bodies package and secreting organelles of the cell. When something is secreted, it is given off by the cell.
Ebola Viruses
The Ebola virus is named for the Ebola river in Africa. In 1976, the first known outbreak of Ebola killed half of the people in a Sudan village; 60% of those who were infected dead.
Where are proteins made?
A structure called nucleolus, which is found in the nucleus, is involved in making proteins.