Evolutionary Biology: Concepts and Mechanisms
Evolutionary Biology: Key Concepts and Mechanisms
Genetics and Population Dynamics
Haplotypes and Linkage Disequilibrium
A haplotype refers to the genotype of linked loci on a chromosome, often used for mitochondrial DNA due to its haploid nature. Linkage disequilibrium describes the non-random association of alleles at different loci. Factors like sexual reproduction and genetic recombination can reduce linkage disequilibrium.
Genetic Load and Population Admixture
Genetic load refers to the fitness
Read MoreUnderstanding Cells: Structure, Function, and Nutrition in Living Organisms
The Cell: The Fundamental Unit of Life
Living organisms are composed of basic units called cells. These cells act as small factories, each performing specific functions and communicating with each other to maintain the organism’s overall health and functionality. Organisms can be single-celled (unicellular) like bacteria and protozoa, or multicellular like animals and plants.
Cell Theory
Scientists have established the cell theory, which states that:
- The cell is the basic unit of life, both structurally
The Vascular System and Blood Flow
The Vascular System & Blood
The Vascular System
A network of vessels that transport blood throughout the body, divided into four main categories:
Arteries
Carry blood away from the heart to different organs.
- Very elastic, can easily stretch and recoil.
- Blood pressure is measured in arteries.
Arterioles
Regulate blood distribution to various tissues in the body.
- Have rings of smooth muscle that can constrict or relax and alter blood flow.
- Arteriole muscle is controlled chemically (Autoregulation) and through
Vital Signs: Understanding and Monitoring Key Health Indicators
Normal Ranges and Influencing Factors
In healthy individuals, vital signs typically fall within specific ranges. However, various factors can influence these values:
- Physiological: Age, weight, sex, physical activity, food intake
- Environmental: Temperature, time of day, altitude
- Psychological: Personality, emotional state, stress response
- Pathological: Infections, bleeding, dehydration, burns, heart/lung/kidney abnormalities
Temperature
Body temperature reflects the balance between heat production (e.g.
Read MoreExtracellular Matrix: Components, Functions & Cell Adhesion
Extracellular Matrix (ECM) Components
Glycosaminoglycans and Proteoglycans
Glycosaminoglycans (GAGs): Long, unbranched polysaccharide chains composed of repeating disaccharide units. They are usually sulfated and contain carboxyl groups, giving them a strong negative charge that attracts cations like Na+. This high concentration of Na+ and the inability of GAGs to fold into compact structures create tissue fluid drag, contributing to the ECM’s resistance to compression forces and providing intrinsic
Read MoreCardiovascular System: Anatomy and Physiology
Cardiovascular System
Sympathetic System
The sympathetic system increases conduction velocity and heart rate (FC), leading to increased force of contraction. It is predominant during physical activity and stress.
Hormone System
Hormones, such as epinephrine and norepinephrine (catecholamines), exert their action through the liver, producing similar effects as sympathetic activity.
Excitoconductor System
This system is responsible for cardiac automaticity and consists of:
- Sinoatrial (SA) node
- Atrioventricular