Genetics and Cell Biology Overview

Definition: Study of heredity and variation in organisms.
Key Concepts:
- DNA Structure: Double helix, nucleotides (adenine, thymine, cytosine, guanine).
- Gene: Segment of DNA that encodes a protein or RNA molecule.
- Alleles: Different forms of a gene.
- Genotype vs. Phenotype: Genotype is the genetic makeup; phenotype is the observable traits.
- Mendelian Genetics: Principles of dominance, segregation, and independent assortment.
- Mutation: Changes in DNA sequence affecting genetic information.

Definition: Study of cells, their physiological properties, structures, and interactions.
Key Concepts:
- Cell Theory: All living organisms are made of cells; cells are the basic unit of life; all cells arise from pre-existing cells.
- Cell Types: Prokaryotic (no nucleus, e.g., bacteria) vs. Eukaryotic (nucleus present, e.g., plant and animal cells).
- Cell Structures:
  - Nucleus: Contains genetic material.
  - Mitochondria: Energy production (ATP).
  - Ribosomes: Protein synthesis.
  - Endoplasmic Reticulum: Protein and lipid synthesis.
  - Golgi Apparatus: Modifying and packaging proteins.
- Cell Membrane: Phospholipid bilayer; regulates what enters/exits the cell.

Definition: Study of interactions between organisms and their environment.
Key Concepts:
- Ecosystem: Community of living organisms and their physical environment.
- Biomes: Large ecological areas (e.g., deserts, forests, tundras).
- Food Chains/Webs: Energy flow in ecosystems; producers, consumers, and decomposers.
- Niche: Role and position of a species in its environment.
- Biodiversity: Variety of life in a particular habitat or ecosystem.

Definition: Change in the heritable traits of biological populations over successive generations.
Key Concepts:
- Natural Selection: Mechanism of evolution; survival of the fittest.
- Mutation: Source of genetic variation.
- Speciation: Formation of new and distinct species.
- Evidence for Evolution: Fossil records, comparative anatomy, molecular biology.
- Common Descent: All living organisms share a common ancestor.

Definition: Study of microorganisms, including bacteria, viruses, fungi, and protozoa.
Key Concepts:
- Microorganisms: Usually unicellular; play roles in decomposition, nitrogen fixation, and disease.
- Bacteria: Prokaryotic cells, diverse metabolic pathways, can be beneficial or pathogenic.
- Viruses: Acellular, require a host to replicate; can cause diseases.
- Fungi: Eukaryotic, decomposers; can be multicellular (mushrooms) or unicellular (yeast).
- Antibiotics: Medications that inhibit bacterial growth; ineffective against viruses.

Study of heredity and variation in organisms.
DNA consists of a double helix structure made up of nucleotides: adenine, thymine, cytosine, and guanine.
Genes are segments of DNA that encode proteins or RNA molecules.
Alleles represent different forms of a gene found at the same locus on homologous chromosomes.
Genotype refers to the genetic makeup of an organism, while phenotype refers to observable traits influenced by the genotype and environment.
Mendelian genetics encompasses principles such as dominance (one allele's expressed over another), segregation (alleles separate during gamete formation), and independent assortment (genes for different traits assort independently).
Mutations are changes in DNA sequences that can alter genetic information and contribute to diversity.

Focuses on the physiological properties, structures, and interactions of cells.
Cell theory asserts that all living organisms are composed of cells, which are the fundamental units of life, originating from pre-existing cells.
Prokaryotic cells lack a nucleus (e.g., bacteria), while eukaryotic cells have a well-defined nucleus (e.g., plant and animal cells).
Key cell structures include:
- Nucleus: Contains genetic material (DNA).
- Mitochondria: Sites of energy production through ATP synthesis.
- Ribosomes: Responsible for protein synthesis.
- Endoplasmic Reticulum: Involved in the synthesis of proteins and lipids.
- Golgi Apparatus: Modifies, sorts, and packages proteins for secretion or use within the cell.
- Cell Membrane: A phospholipid bilayer controlling the movement of substances in and out of the cell.

Investigates interactions among organisms and their environment.
Ecosystems are communities of organisms interacting with their physical surroundings.
Biomes are large ecological areas characterized by distinct climates and vegetation, such as deserts and forests.
Food chains and food webs illustrate energy flow in ecosystems, involving producers (e.g., plants), consumers (e.g., animals), and decomposers (e.g., fungi).
The niche of a species defines its role and position within an ecosystem, including resource use and relationships with other species.
Biodiversity refers to the variety of life, including species richness and ecosystem diversity in specific habitats.

Describes changes in heritable traits in biological populations over generations.
Natural selection acts as the primary mechanism of evolution, favoring traits that enhance survival and reproduction.
Mutations create genetic variation, serving as the raw material for evolution.
Speciation is the process through which new species arise, often due to geographical or reproductive isolation.
Evidence for evolution includes fossil records, comparative anatomy, and molecular biology studies.
Common descent indicates that all living organisms share a common ancestor through evolutionary processes.

Examines microorganisms, encompassing bacteria, viruses, fungi, and protozoa.
Microorganisms are largely unicellular and contribute to ecological processes such as decomposition and nitrogen fixation, along with causing diseases.
Bacteria are prokaryotic organisms with diverse metabolic capabilities; they can be beneficial (e.g., gut flora) or pathogenic (causing infections).
Viruses are acellular entities that require a host organism to replicate and can lead to various diseases.
Fungi, which may be multicellular (like mushrooms) or unicellular (like yeast), act as decomposers in ecosystems.
Antibiotics serve as medications that inhibit bacterial growth; however, they are ineffective against viral infections.