Biotic and Abiotic Organization, Human Cells, and Body Systems

Posted on Jan 15, 2025 in Biology

Biotic and Abiotic Levels of Organization

  1. Atom Level: Consists of atoms of the chemical elements from which living matter is formed: carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur.
  2. Molecule Level: Formed by the joining of two or more atoms.
  3. Macromolecule Level: Formed when molecules join together.
  4. Organelle Level: When macromolecules join together, they form organelles.
  5. Cellular Level (Biotic): Organelles can be considered the organs of cells. They come together to form cells, which are the fundamental units of living things.
  6. Multicellular Level: All organisms that contain more than one cell are classified into this level, and they are classified into the following sublevels:
    • Tissue Sublevel: Cells with the same shape and function form tissue.
    • Organ Sublevel: Organs are formed from different types of tissue that work together to perform a specific function.
    • Organ System Sublevel: Organ systems are made up of various organs that work together to carry out a specific function.

Cell Characteristics

Structure and Functions

  • Cell Membrane: Surrounds and protects the cells.
  • Cytoplasm: Contains many different organelles that carry out vital functions.

Types

  • Prokaryotic Cells: Have no nucleus. They are only found in bacteria.
  • Eukaryotic Cells: Have a nucleus. They are found in all other living things.

Human Cells

  1. The nucleus contains genetic material.
  2. The cell membrane protects the cell from the outside.
  3. This contains the cytoskeleton.
  4. Vacuoles store a variety of substances.
  5. Mitochondria break down glucose to produce energy as part of cellular respiration.
  6. Ribosomes produce proteins and are either attached to the rough endoplasmic reticulum (RER) or are free in the cytoplasm.
  7. The rough endoplasmic reticulum (RER) stores proteins formed in the attached ribosomes and transports them around the cell.
  8. The Golgi apparatus transports substances to the outside of the cell.
  9. Lysosomes are involved in digestion within the cell.
  10. The smooth endoplasmic reticulum produces lipids and breaks down toxic material.

Infectious Illness

  • Direct Transmission: Pathogens are transferred directly from the infected person to another person via physical contact.
  • Indirect Transmission: Pathogens are transferred via an intermediary from the host to another person.

Internal Defenses

Acquired immunity is built up throughout our lives as a result of the body suffering different infections. Lymphocyte B-cells recognize antigens and turn into antibody-producing plasma cells. Lymphocyte T-cells are able to destroy cells that have been damaged.

The Nutrition Process

The nutrition process requires four closely related systems that work together to perform the necessary functions: the digestive, respiratory, circulatory, and excretory systems. It is divided into three stages:

  1. Obtaining nutrients
  2. Distributing nutrients and oxygen
  3. Eliminating waste

Organs of the Digestive System

  • Mouth: The entrance to the digestive tract.
  • Pharynx: A muscular tube that connects the digestive system to the respiratory system.
  • Esophagus: A muscular tube around 25 cm long.
  • Stomach: Connected to the esophagus via a sphincter.
  • Liver: The largest internal organ in the body.
  • Gallbladder: A pear-shaped structure located under the liver.
  • Pancreas: A long, narrow organ with two ducts: the main pancreatic duct and the accessory duct.
  • Small Intestine: Starts at the pylorus and ends at the ileocecal valve, where it joins the large intestine.
  • Large Intestine: Connected to the small intestine via the ileocecal valve.

How Does Our Digestive System Work?

We have two processes:

  • Mechanical Digestion: Food is ground, cut up, and mixed with digestive juices to form a paste.
  • Chemical Digestion: Food is broken down by hydrolytic enzymes.
  1. Preparation of Food and Digestion in the Mouth: Three processes: mastication, insalivation, and deglutition.
  2. Deglutition: The movement of the food bolus from the mouth towards the pharynx.
  3. Gastric Digestion: Food going down the esophagus enters the stomach when the cardiac sphincter relaxes.
  4. Intestinal Digestion: The chyme moves into the duodenum, where it is mixed with pancreatic juice, bile, and intestinal juice.
  5. Intestinal Absorption: Nutrients are absorbed by the intestinal villi.
  6. Egestion: The substances fermented by the intestinal flora are compacted to form feces.

What Makes Up the Respiratory System?

  1. Nasal Cavities
  2. Pharynx
  3. Larynx
  4. Trachea
  5. Bronchi
  6. Lungs

Work of the Respiratory System

  • Ventilation: Air moving in and out of the lungs.
  • Gas Exchange: Oxygen in the air inside the lungs transfers to the blood.
  • Inhalation: Air in, chest expands, diaphragm flattens.
  • Exhalation: Air out, chest contracts, diaphragm relaxes.