Organisation of Multicellular Organisms - 3.2 Flashcards
3.2
What are living things called?
Living things are called organisms.
What is a cell?
A cell is a tiny volume of a watery fluid enclosed in a membrane and is the smallest unit that can live on its own and that makes up all living organisms and the tissues of the body.
What are the different characteristics of Prokaryotic cells and Eukaryotic cells?
Eukaryotic cells are found in multicellular organisms and are found in most living organisms.
1. Have a nucleus.
2. Have membrane-bound organelles.
3. Have more DNA than prokaryotic cells.
4. Larger than prokaryotic cells (1 – 100um).
Prokaryotic cells are single-cell organisms such as bacteria.
1.No membrane-bound organelles
2. No nucleus.
3. Have less DNA than eukaryotes.
4. Do not have a nucleus
5. Smaller than eukaryote cells (1 – 10 um).
What is the hierarchical structure of organisation?
Groups of cells make up tissues. Various tissues make up an organ. Various organs make up organ systems. Multiple organ systems make up an organism. For example, groups of cardiac muscle cells make cardiac muscle tissue. Various cardiac muscle tissues then make up the heart and blood vessels. The heart & blood vessels make up the circulatory system.
How do organ systems in a multicellular organism function together to ensure survival?
Organ systems in a multicellular organism are interdependent meaning they need to work together to ensure survival. For example, the respiratory system supplies oxygen to the circulatory system, which transports it to cells for energy production, while the digestive system provides nutrients needed for survival.
What is the nervous tissue?
The nervous tissues consist of neuron cells that transmit electro-chemical nerve impulses to communicate with other tissues/organs. For example - The brain and spinal cord are made up of nervous tissue.
What is the muscle tissue?
The muscle tissue consists of muscle fibres that contract and relax under nervous stimulation to provide movement. Skeletal muscles are controlled voluntarily, whereas smooth and cardiac muscles are involuntarily controlled. For example - skeletal, smooth and cardiac.
What is the epithelial tissue?
The epithelial tissue covers and protects the internal and external surfaces of various organs. For example - Squarimo, columnar & ciliated.
What is connective tissue?
The connective tissue provides structures support by binding to other tissues and organs in the body
Describe the characteristics of nervous tissue that make it well adapted to its function.
Nervous tissue is well adapted to transmit electrical signals throughout the body. Nervous tissue is made up of neuron cells, which consist of dendrites, axon and axon terminals and myelin. The dendrites are adapted to receive messages, whereas axons transfer messages to the axon terminal. Axons are often insulated by a myelin sheath, which is a fatty protective coating that speeds up the transmission of signals. Neurons that are used frequently adapt and have thicker myelin sheaths.
Describe the characteristics of dense fibrous connective tissue that make it well adapted to its function.
Dense fibrous connective tissue produces a high concentration of dense collagen fibres for strength and flexibility. Making them well suited to their function as tendons and ligaments that join bones to muscles and muscles to muscles.
Describe the characteristics of simple squamous epithelial tissue that make it well adapted to its function.
Simple squamous epithelial tissue is made of a single layer of thin, flat cells, making it well adapted for exchange surfaces. Its smooth surface reduces friction, making it ideal for lining blood vessels, alveoli in the lungs, and other areas where efficient exchange of gases or fluids is essential.
Describe the characteristics of stratified squamous epithelial tissue that make it well adapted to its function.
Stratified squamous epithelial tissue consists of multiple layers of cells. The outer layer of the skin consists of tightly packed stratified squamous epithelial cells serving as a barrier for dehydration and invasion by pathsogens. An example used for is skin,
Describe the characteristics of ciliated columnar epithelial that make it well adapted to its function.
Ciliated columnar epithelial tissue consists of tall, column-shaped cells with hair-like projections called cilia, which help move mucus and trapped particles. It is well adapted for clearing debris from the respiratory system.
What is the main function of the respiratory system?
The main function of the respiratory system is to deliver air to the lungs so the exchange of oxygen and carbon dioxide can occur in the alveolus. Trachea, lungs, bronchi, diaphragm and intercostal muscles are a few organs included in the respiratory system.
What is the main function of the circulatory system?
The main function of the circulatory system is to transport blood around the body to deliver nutrients to cells and collect waste products throughout the body. Heart, arteries and veins are part of the circulatory system.
What lifestyle choices affect the function of organs and systems?
A diet of high sugars and saturated fats can result in reduced pancreatic cells, which produce insulin, leading to the inability of an organism to control blood glucose levels resulting in type 2 diabetes.
A diet high in salt and chronic stress can increase blood pressure and the risk of hypertension, where the blood pressure in blood vessels is too high, resulting in hypertension.
A diet high in saturated and trans fats increases blood cholesterol levels resulting in fatty deposits building up against the walls of blood vessels resulting in Atherosclerosis.
A diet low in calcium and vitamin D can result in poor bone density, resulting in Osteoporosis, where bones are weak and fragile.
What is homeostasis?
Homeostasis is the process by which organisms maintain a stable internal environment (such as temperature, pH, and water balance) despite external changes. It involves systems like the endocrine and nervous systems to regulate key bodily functions.
What is the fluid-mosaic model of membrane structure?
The cell membrane consists of a phospholipid bilayer with embedded proteins. Hydrophilic heads face outward, and hydrophobic tails face inward. Glycoproteins and glycolipids have attached carbohydrate chains. The membrane controls material exchange and separates the cell’s internal and external environment.
