Lab 4 Dropbox
Introduction
All living things are composed of cells, the basic structural and functional unit of living organisms that are capable of independent functioning. Cells vary in size, generally ranging from 10 µm to 100 µm, with animal cells being the smallest and plant cells being the largest in size.
One of the basic principles of biology, proposed by Theodor Schwann and Matthais Schleiden in 1836, is cell theory which is defined in the following three statements:
All living organisms are composed of one or more cells, which can be unicellular (one cell) or multicellular (more than one cell).
The cell is the basic unit of life.
New cells arise from pre-existing cells.
Cells are divided into one of two major classifications, eukaryotic or prokaryotic.
A eukaryotic cell contains a membrane-bound nucleus and organelles. An organelle is a membrane-bound structure within a cell that provides a specific cellular function; each organelle has a specific job to do. It is the presence of a nucleus that gives eukaryotes their name, and is derived from the Greek words eu, meaning “good” and karyon, which means “nut or kernel.” Organisms that contain eukaryotic cells are referred to as eukaryotes. All large organisms, including plants, fungi, and animals, are examples of eukaryotes. Some unicellular organisms are also eukaryotes.
A cell that lacks a membrane-bound nucleus is a prokaryotic cell. The word prokaryote is a combination of the Greek words pro, which means “before,” and karyon, which means “nut or kernel.” Organisms that contain prokaryotic cells are referred to as prokaryotes. Most prokaryotes are single-celled, although some are multicellular. Bacteria and archaea are examples of prokaryotes. Archaea was not discovered as a major domain of life until the late 1970s by Dr. Carl Woese at the University of Illinois.
Adapted from Hands-on Labs.
Viruses
“From single-celled organisms to human populations, viruses affect all life on earth, often determining what will survive. But viruses themselves also evolve. New viruses, such as the AIDS-causing HIV-1, may be the only biological entities that researchers can actually witness come into being, providing a real-time example of evolution in action.” Villarreal, L. P. (2004). Are viruses alive? Scientific American-American Edition, 291, 100-105. (Links to an external site.)
Learning Objectives
Identify and label the key features/organelles of cells from plants, animals, and bacteria.
Classify cells as prokaryotic or eukaryotic and compare and contrast features of each.
Summarize the key functions of cell organelles.
Watch the following videos:
1https://youtu.be/cj8dDTHGJBY
2https://youtu.be/9UvlqAVCoqY
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