Ecological Systems and Population Dynamics: An In-Depth Analysis
Ecology and Distribution of Ecological Systems
Ecology is the study of interactions among organisms and their environment, including biotic (living) and abiotic (non-living) factors.
Levels of Study:
- Organismal: Focuses on individual organisms and their interactions with the environment.
- Population: Examines factors that regulate population growth and size.
- Community: Studies interactions among different species in a particular area.
- Ecosystem: Investigates interactions between communities and their environments,
Protein Structure, Enzymes, and Vitamins: Comprehensive Insights
Protein Structure: Levels and Significance
Protein structure refers to the multi-level spatial arrangement of proteins. There are four levels:
Primary Structure
The primary structure is the specific order in which amino acids (aa) are arranged in a polypeptide chain. Each of the 20 amino acids can join without restriction. Polarity varies among amino acid residues, and the chain has terminal carboxyl (COOH) and amino (NH2) groups. Some residues are polar and oriented outward, while others are nonpolar
Read MoreUnderstanding Genetics: From Genes to Chromosomal Alterations
Genes: Fragments of DNA containing information related to one characteristic.
Gene pairs: Two genes, each located on a different chromosome of a homologous pair, that contain information about the same characteristic.
Dominant genes: Genes that manifest their expression in a hybrid individual, preventing another gene, called recessive, from expressing different information about the same characteristic.
Codominant genes: Genes in hybrid individuals where both characteristics have the same strength,
Human Digestion: Processes, Health, and Food Safety
Chewing
During chewing, food is fragmented, and its presence in the mouth stimulates the secretion of saliva (which moistens and lubricates the food bolus) by the salivary glands.
Swallowing
Once the bolus is crushed and insalivated, it passes from the mouth into the esophagus. This act is called swallowing. Swallowing is a voluntary phase, in which the tongue pushes the bolus against the palate and elevates the soft palate, and two involuntary phases: the first, when the bolus passes into the pharynx,
Read MoreEvolution and the Origin of Life: From Darwin to Modern Theories
The Origin of Variability
Darwin could not explain how such variability arises on which natural selection acts, and how such variability is maintained generation after generation. Many of the differences between individuals are due to genetic variations, and these are generated by two processes: mutation and sexual reproduction.
Mutations as a Source of Variability
Mutations are changes that occur randomly in genes. Those that affect the gametes are transmitted to offspring. Types:
- Harmful mutations:
DNA Replication, Transcription, and Translation in Molecular Genetics
Molecular Genetics: DNA Replication, Gene Expression, and Mutation
Concept of Gene
A gene is a fragment of DNA containing encoded information for the synthesis of structural and regulatory proteins.
Characteristics of Genes
- Prokaryotes: Genes are continuous units; all information contained in the gene leads to protein synthesis.
- Eukaryotes: Genes are fragmented. Sequences consist of information to synthesize proteins (exons) and other sequences that are eliminated in the transcript (introns).
Replication
Replication
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