Understanding Genes, Alleles, and Mendelian Genetics
A gene is a fragment of DNA that contains the information needed to make a protein. Qualitative characters are determined by a single gene, while quantitative characters are influenced by many genes.
Alleles, Genotypes, and Phenotypes
Alleles are different versions of the same gene within a population. An individual is homozygous for a specific gene if they have two identical alleles on their homologous chromosomes. They are heterozygous if they possess two different alleles for that gene.
- Genotype:
Understanding Cells: Anatomy, Function, and Division
Cell Structure and Function
A cell is the smallest functional and anatomical unit of living beings. Some organisms consist of a single cell (unicellular), while others have multiple cells (multicellular). Cells perform the following vital functions:
- Nutrition: Taking in molecules from the environment and transforming them into energy.
- Relationship: Communicating with the external environment.
- Reproduction: Forming new cells from existing ones, with the same genetic information.
The cell theory, developed
Read MoreUnderstanding the Key Features and Levels of Living Things
Key Features of Living Things
- Complex Organization: Molecules interact in complex internal and external functions.
- Cellular Structure: Can be unicellular or multicellular.
- Feeding and Metabolism: Capture and use energy and matter for growth, development, and maintenance.
- Responsiveness: Detect external stimuli and respond appropriately.
- Reproduction: Ability to create new individuals, similar or different from themselves.
Levels of Biological Organization
Subatomic Level
Composed of neutral protons and
Read MoreCellular Organelles and Levels of Biotic Organization
Cellular Organelles
Cellular organelles comprise a supramolecular complex. Although they have their own characteristics, they cannot be considered living beings, as they do not meet the criteria for nutrition, relationships, and reproduction. Inside the cell, there are several cellular organelles such as mitochondria, peroxisomes, and the endoplasmic reticulum.
Viruses are macromolecular complexes consisting of two types of macromolecules: proteins and nucleic acids, and in some cases, lipids.
Levels
Read MoreCarbohydrates and Lipids: Monosaccharides to Polysaccharides
Carbohydrates and Lipids
Understandings: Monosaccharides and Polymers
Monosaccharide monomers are linked together by condensation reactions to form disaccharides and polysaccharide polymers.
| Monosaccharides | Glucose | Energy molecule used in aerobic respiration |
| Galactose | Nutritive sweetener in foods | |
| Fructose | Fruit sugar | |
| Disaccharides | Maltose | Malt sugar found in barley, consists of 2 glucose molecules |
| Lactose | Sugar found in milk | |
| Sucrose | Transport sugar found in plants because of its solubility | |
| Polysaccharides | Starch | Storage |
Health Hazards: Environmental, Chemical, and Biological Risks
Health Hazards: An Overview
Physical Environmental Insults: Ionizing radiation is a form of energy that can modify the structure of matter and cause changes in our cells. It can be natural or artificially produced by temperature variations. High temperatures with excessive humidity prevent the evaporation of sweat and can be lethal.
Chemical Hazards
Chemicals: Air pollution occurs when human activities alter the composition of the air by adding compounds that affect health. Water pollution, from domestic
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