Levels of Organisation

Levels of Organisation

Core
• Relate the structure of the following to their
functions:
• ciliated cells – in respiratory tract
• root hair cells – absorption
• xylem vessels – conduction and support
• muscle cells – contraction
• red blood cells – transport

Define:
• tissue
• organ
• organ system

Ciliated Cells - These are cells with tiny cilia. Many cilia can be found in your throat and are generally used for pushing substances along e.g mucus when you have a cold. They can also be found on the lining of the intestines but that is more for the absorption of enzymes (discussed later)

Root Hair Cells - These Cells absorb water and nutrients from surrounding soil to benefit the plant. It absorbs water by process of Osmosis, down a water concentration gradient.

Xylem Vessels - Once water has been absorbed into the plant root hair cell, it proceeds to the Xylem. At the top of the Xylem is a low pressure whereas at the bottom is a higher pressure, this causes water to flow up the Xylem to the rest of the plant.

Muscle Cells - These are the cells which make up muscles. They are generally used for movement/contraction. Cells make up a tissue and the main feature of muscle tissues is their ability to shorten/contract to promote movement.

Red Blood Cells - The main function of Red blood cells is to transport Haemoglobin. Once Oxygen has gone through the Lungs, it is Oxygenated and contains Haemoglobin, it takes this Haemoglobin to other cells around the body and oxygenates them. Red blood cells contain no nucleus and have a biconcave shape, both of these features allow for a larger surface area in which to carry Haemoglobin. Red blood cells are also very small, which means they can fit through even the tiniest of Capillaries and oxygenate every cell in the body.

Tissue -  a group of cells with similar structures, working together to perform a shared function.

Organ - This can be defined a as a group of tissues working together to perform a single bodily function. The lungs oxygenating blood could be seen as one example.

Organ System - This can be defined as a group of organs working in a system to carry out body functions. The organs involved must have similar functions and work towards the same goal for example, all the organs in the Circulatory System.