Science Fundamentals: Key Concepts and Definitions
Science Fundamentals: Key Concepts
Science is a body of knowledge and a process for generating that knowledge.
The Scientific Method
What is science and the scientific method based on? Evidence
An observation is a description, measurement, or record of any object or scientific phenomenon.
After it has been supported by a predictable experimental outcome, a scientific hypothesis still cannot be considered to have been proven true.
In a controlled experiment, which variable is manipulated? Independent variable
Basic
Read MorePlate Tectonics: Shaping Earth’s Crust
The study of the processes that shape the broad outlines of the Earth’s crust through the creation of continents and oceans, mountains and sea trenches, and so on.
The plates are pieces (more or less rigid) in the most superficial part of the Earth that move about with respect to others. For example, imagine chunks of melon peel slipping on the fruit’s flesh. The interactions between these plates result in tectonic processes. The theory of plate tectonics elegantly explains a wide range of geological,
Read MoreEvolution and Speciation: A Comprehensive Summary
Theory of Natural Selection
Individuals within a population exhibit heritable variations. Organisms live longer than the environment can support, leading to competition. Some inherited variations give individuals survival advantages.
The Synthetic Theory (Neo-Darwinism)
This theory builds upon Darwinian ideas, incorporating new findings. Its core principles include:
- The evolving unit is the population.
- Environmental conditions favor the reproduction of well-adapted individuals.
- Evolution is driven by
Evolutionary Agents, Adaptation, and Biodiversity
Evolutionary Agents
Evolutionary agents cause changes in gene frequencies within a population. These agents include:
- Mutations: Changes in genetic information that introduce new alleles, leading to variability within the population. Mutations occur randomly, and the environment determines whether a mutation is neutral, harmful, or beneficial.
- Genetic Drift: Random changes in allele frequencies from one generation to the next, particularly significant in small populations.
- Gene Flow: The transfer of
Animal and Plant Cells: Features, Processes, and Energy Transfer
Animal and Plant Cells: Key Features
Animal Cells:
- Nucleus: Controls the activities of the cell.
- Cytoplasm: Where chemical reactions take place.
- Cell Membrane: Controls the passage of substances.
- Mitochondria: Structures in the cytoplasm responsible for energy production.
- Ribosomes: Where protein synthesis takes place.
Plant Cells:
- All have a cell wall made of cellulose, which strengthens the cell and provides support.
Additional Features in Plant Cells
- Chloroplasts: Found in all green parts of plants, responsible
Cell Biology: Functions, Theory, and Classification
What are Vital Functions?
Vital functions are the processes that sustain life.
Some functions specialize in groups of cells in a multicellular organism, such as a human.
These include nutrition, relationship (response to stimuli), and reproduction.
Single-celled vs. Multicellular Organisms
The main difference in functioning between a cell in a single-celled organism and one in a multicellular organism is that a single cell must perform all vital functions individually and independently. In contrast,
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