Animal Physiology: Nutrition, Digestion, Respiration, Circulation, and Excretion
Animal Physiology: Key Systems
Nutrition
The process by which living organisms obtain energy and matter for growth, development, and vital functions. Animals use energy from organic matter catabolism.
- Ingestion and digestion of food to release nutrients.
- Distribution of nutrients to body cells.
- Absorption of oxygen and transport to cells.
- Cell metabolism
- Waste removal from cells.
- Waste excretion.
Digestion
Macromolecule transformation into smaller, absorbable molecules.
- Physical/Mechanical: Fragmenting food,
Bacteria, Viruses, and the Immune System: A Deep Dive
Bacteria: Reproduction and Genetics
Asexual Reproduction
Bacteria, as primitive organisms, primarily reproduce asexually through fission (simple division or bipartition). The original cell divides, resulting in two identical daughter cells. This process lacks variability.
Sporulation
A more evolved form of asexual reproduction is sporulation. Under negative environmental conditions (changes in humidity, temperature, or nutrient scarcity), bacteria form spores—resistant structures that remain dormant.
Read MorePlant and Animal Nutrition
Plant Nutrition
Bryophyte Nutrition
Seedless plants are small and have a thallus organization. Although they have colonized the terrestrial environment, they lack true roots for water and mineral absorption, and vascular tissue for transport.
Cormophyte Nutrition Process
- Absorption of water and minerals by roots (root hairs are coated in a piliferous layer).
- Transportation of xylem sap.
- Gas exchange (carbon dioxide and oxygen).
- Transportation of phloem sap.
Xylem Transport
Water and mineral salts enter
Read MoreMicrobiology: Bacteria, Viruses, and Eukaryotes
Item 21
1. Concepts and Types of Organisms
Organisms, often only visible with a microscope, are classified as prokaryotic or eukaryotic, and unicellular or multicellular. Depending on their nutrition type, they are divided into prokaryotes (archaebacteria, eubacteria—Kingdom Monera) and eukaryotes (algae, protozoa, fungi—Kingdom Protista). Viruses are not considered living organisms.
2. Viruses
Viruses are simple, microscopic particles formed by DNA or RNA and surrounding proteins. Free viruses
Read MoreSeed Plants: An In-Depth Look at Spermatophytes
Spermatophytes: The Seed-Bearing Lineage
Spermatophytes are a monophyletic group encompassing all vascular plants that produce seeds. The term originates from the Greek words “sperma” (seed) and “phyton” (plant), translating to “seed plants.” This group aligns precisely with the traditional classification of flowering plants, as the pollen grain in seed plants generates a pollen tube to reach the ovum, facilitating fertilization.
Gymnosperms: Vascular Plants with Naked Seeds
Gymnosperms are vascular
Read MoreAnimal Physiology: Key Mechanisms and Systems
Osmoregulation and Excretion
Osmosis and Water Balance
Osmosis is the movement of water across a semipermeable membrane from an area of low solute concentration to an area of high solute concentration. Excretion is the process of removing metabolic wastes and toxins from the body. Animals employ different strategies to maintain water balance:
- Osmoconformers: These animals, like jellyfish, maintain an internal osmolarity similar to their environment.
- Osmoregulators: These animals, like humans, actively