The Cell Theory
Two Basic Categories of Cells
Eukaryotic Cells
All eukaryotic cells contain the following organelles: cell membrane, ribosomes, nucleus, mitochondria, endoplasmic reticulum, cytoplasm, Golgi bodies, lysosomes, nucleolus, vacuole Organelles and Their Functions Other Important Organelles include: Cell membrane (controls what enters and exits the cell), cell wall only in plants and bacteria (provides structure and support), cytoplasm (jelly-like fluid that fills the cell between the cell membrane and nuclear membrane, holds all organelles in place and responsible for the movement of organelles around the cell), centrioles in animal cells (play a role in cell division), nucleolus (makes mRNA and ribosomes)
Plant cells have no centrioles, have a large central vacuole, contain chloroplasts (carry out the process of photosynthesis), surrounded by a cell wall (provides the cell with structure, made up of cellulose) Animal cells contain centrioles (play a role in cell division) and several small vacuoles Life FunctionsThe processes of activities, common to all living things.
Nutrition
Transport
Respiration (Cellular)
Excretion
Regulation
8 Life Functions These 8 life functions are carried out by all living things. Nonliving things may go through some but not all of these life processes or functions. All of these life functions together is metabolism. The bodies ability to maintain a stable internal environment even as the external environment changes is known as homeostasis. Respiration: Energy is produced from the breakdown of material
Regulation: Control and coordination of all life processes and maintenance of homeostasis Reproduction: Production of new individuals Growth: Increase in size or cell number Excretion: Removal of cellular wastes from the body Nutrition: Organisms take in materials from the environment and change them into forms they can use Transport: Absorption and circulation of materials (oxygen, nutrients, wastes, etc.) Synthesis: When complex molecules are made from less complex molecules Metabolism: All the chemical life processes that occur in the body Homeostasis: Keeping the internal environment of an organism stable even if the external environment changes
Organization of Life Levels of Organization
from least complex to most complex Organelle --> Cell --> Tissue --> Organ --> Organ system --> Organism Problem: Does temperature affect the brightness of a glow stick?
Hypothesis: Here students created their own hypothesis (educated guess) using an "If... then..." statement. For example, If we subject glow sticks to high temperatures, then they will glow brighter. Experiment: Now the students carry out the experiment using 3 beakers with different water temperature in each, a thermometer, and 3 glow sticks. The control group is the beaker filled with room temperature water, it is used for comparison. The experimental group is the different water temperatures that the glow sticks were placed in (the glow stick in the beaker with ice and the glow stick in the beaker with hot water. Record and Analyze Data: Students record the temperatures of the beakers, make observations of the glow sticks' brightness and make comparisons. Conclusion: Was the hypothesis supported or refuted by the data? List any potential sources of error. Answer conclusion questions. Hypothesis: Here students created their own hypothesis (educated guess) using an "If... then..." statement. For example, If we subject glow sticks to high temperatures, then they will glow brighter. Experiment: Now the students carry out the experiment using 3 beakers with different water temperature in each, a thermometer, and 3 glow sticks. The control group is the beaker filled with room temperature water, it is used for comparison. The experimental group is the different water temperatures that the glow sticks were placed in (the glow stick in the beaker with ice and the glow stick in the beaker with hot water. Record and Analyze Data: Students record the temperatures of the beakers, make observations of the glow sticks' brightness and make comparisons. Conclusion: Was the hypothesis supported or refuted by the data? List any potential sources of error. Answer conclusion questions. How do scientists obtain new information?
Observations
The Scientific Method
Parts of an Experiment
How can we make our experiment more reliable?
How can we increase the validity of our experiment?
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