Cell Organelles: Structure, Function, and Energy Production
Essential Cellular Organelles: Structure and Function
Membrane-Bound Organelles
Golgi Apparatus
The Golgi apparatus consists of flattened sacs (cisternae) and independent vesicles surrounded by a membrane and assembled in groups called dictyosomes. Its function is the secretion of substances taken from the endoplasmic reticulum and destined for lysosomes.
Lysosomes
Lysosome Structure and Role: These are spherical vesicles surrounded by a membrane, which contain hydrolytic enzymes. They are responsible
Read MoreCore Concepts in Plant Biology and Animal Diversity
Plant Evolution and Life Cycles
- Land plants evolved from green algae (Charophytes).
- The gametophyte is haploid (n) and produces haploid gametes by mitosis.
- Fusion of gametes gives rise to the diploid (2n) sporophyte, which produces haploid spores by meiosis.
- Bryophytes lack specialized tissues for support and water conduction.
- Vascular plants have two types of vascular tissue: xylem and phloem.
- Xylem conducts most of the water and minerals.
- Phloem consists of living cells arranged into tubes, distributing
Human Nutrition: Process, Nutrients, and Infant Feeding
The Nutrition Process: Ingestion, Digestion, Absorption, and Expulsion
Ingestion
Ingestion involves the mechanical and chemical preparation of food before it enters the stomach:
- Chewing (Mastication): This is the crushing and fragmentation of food, carried out by the tongue and the teeth.
- Insalivation: This is the impregnation of food with saliva, secreted by the salivary glands, until it becomes a mass called the food bolus.
- Swallowing (Deglutition): The food bolus passes through the pharynx and esophagus
Anatomy and Function of Digestive & Respiratory Systems
The Human and Avian Digestive System Anatomy
Pharynx: Swallowing and Lymphocyte Maturation
The Pharynx is a muscular tube that leads into the next portions of the digestive tract: the esophagus and trachea. The tonsils are used for the maturation of lymphocytes. Below the cartilaginous fold belonging to the larynx is the epiglottis, which covers the glottis during swallowing to prevent food from passing into the trachea. The medulla controls swallowing, including closing the nostrils by raising the
Read MoreBiotechnology Fundamentals: Genetics, Recombinant DNA, and Therapeutics
Biotechnology: Definitions and Core Concepts
Definition: Biotechnology uses living organisms or their products to solve problems or create useful items.
Historical and Modern Techniques
Historical Uses
- Fermentation
- Selective breeding
- Antibiotics
Modern Techniques
- Gene cloning
- Genetic engineering
- Recombinant DNA
- CRISPR-Cas (Gene Editing)
- Synthetic genomes
Disciplines Involved
- Biology
- Chemistry
- Physics
- Mathematics
- Computer science and Bioinformatics
- Engineering
Applications of Biotechnology
- Disease-resistant crops
- Golden
Comprehensive Biological Concepts: Immunity, Behavior, & Reproduction
The Biological Basis of Immunity
Innate Immunity
- Invertebrates: Exoskeleton, lysozyme, hemocytes, recognition proteins.
- Vertebrates: Skin and mucous membranes, phagocytes (neutrophils, macrophages), Toll-like receptors (TLRs), antimicrobial peptides, complement system, natural killer (NK) cells, interferons.
Inflammation and the Lymphatic System
- Triggered by injury or infection; involves mast cells releasing histamine and cytokines.
- Lymph nodes contain macrophages and dendritic cells for pathogen clearance