Biology Flashcards
What are the three types of microscopes?
Simple Microscope: Single lens. 10x-20x magnification
Compound Light Microscope: Two or more lenses. Up to 2000x magnification (most are under 400x). The most common microscope in science classes and medical laboratories.
Electron Microscope: Powerful microscopes used for scientific research. Magnification up to 10 million times.
How do you calculate the magnification of a microscope?
Multiply the objective lens (the one near the sample) by the eyepiece lens (the one close to your eye) to get the total magnification.
ie. 4x eyepiece and 10x objective would equal 40x total magnification
What are the seven characteristics of all living things?
- Made up of cells
- Take in nutrients
- Need energy
- Produce waste
- Respond to stimuli
- Grow
- Reproduce (have babies)
What are the three principles of cell theory?
- All living things are made up of one or more cells.
- All living cells come fro other cells.
- The cell is the basic unit of life.
What do you need to see a virus?
An electron microscope, because viruses are extremely small.
What are viruses made of?
Viruses consist of a piece of DNA covered by a protective protein.
How do viruses reproduce?
Viruses reproduce by injecting their DNA into a host cell and tricking it into manufacturing new viruses. The viruses reproduce in the cell, preventing the cell from functioning properly.
What are some examples of viruses?
HIV (Human Immunodeficiency Virus), causes AIDS
Influenza
COVID
What is the difference between unicellular and multicellular organisms?
Unicellular: describes a single celled living thing
Multicellular: describes a living thing made up of multiple cells (like humans)
What are some of the functions performed by organelles inside a cell?
Organelles literally means “little organs” and, like human organs, they perform specific tasks to help keep cells alive. They include:
- Providing a structure and form
- Forming a barrier between the cell and the environment.
- Building and repairing cells.
- Synthesizing materials
- Storing and releasing energy
- Getting rid of waste material
- Multiplying in number
What are the three major parts of a cell?
- Cell membrane: The thin, flexible structure that surrounds the cell. Regulates what enters and exits the cell. Controls the movement of food, waste and other substances.
- Nucleus: The ‘brain’ of the cell. Controls the functions of the cell. Contains genetic information through DNA.
- Cytoplasm: A jelly-like fluid in which organelles are found. This is where many chemical reactions take place within the cell.
What does the mitochondrian do?
[ an organelle ]
Converts the energy stored in food into usable energy for the cell. The ‘powerhouse’ of the cell.
What does the ribosome do?
[ organelle ]
Manufactures proteins, the building blocks for structures in the cell.
What does the endoplasmic reticulum do?
[ organelle ]
A network of flattened tubes that transport proteins within the cell.
What does the Golgi Body do?
[ organelle ]
Sorts and packages proteins in membrane-wrapped structures called vesicles.