Beneficial Microorganisms vs Harmful Microorganisms
- Process of fermentation: Yoghurt, Cheese, Bread, Vinegar, Wine
- Beneficial Bacteria are found in our intestines and help us digest our food.
- Bacteria are also used to make vaccines to prevent disease. Some fungia re used to make medicines called antibiotics.
- Some microorganisms are decomposers. They produce enzymes that break down dead plants and animals. Microorganisms turn this dead material into nutrients which enter the soil. They are Nature’s way of recycling. This process is called decomposition.
- Germs are microorganisms that cause disease:
Bacteria: Some reproduce inside our body and cause infections: Sore throats, acne, ear infections and even cavities in our teeth.
Viruses: They need to be inside a living thing, like a plant, animal or person, to grow and reproduce. They spread easily from one person to another: Chickenpox, measles and influenza.
Fungi: Mould is a type of fungi that grows on food or sometimes on our bodies. (Athlete’s Foot)
Amoebae: They spread disease through water. They can cause intestinal infections that give us diarrhoea, nause or stomach ache.
False – True – True – True - True
What is a cell?
The cell is the basic unit of life. Cells join together to form different living organisms. Some organisms, like bacteria or amoebae, are made up of only one cell and are called unicellular organisms. Other organisms are made up of many cells. They are called multicellular organisms. Plants, animals and humans are made up of millions of cells.
The cell structure:
All cells have three things in common:
- The NUCLEUS is at the centre of the cell. The nucleus controls the cell.
- CYTOPLASM fills the inside of the cell and supports its structure. It is mostly composed of water. There are organelles in cytoplasm. Organelles perform operations for the cell.
- The MEMBRANE is the skin of a cell. It limits and protects the cell. The membrane lets nutrients into the cell.
The organisation of multicellular organisms:
A cell is a basic unit of life. Cells that perform the same function group together and form tissue. For example, muscle cells group together and form muscle tissue. Tissues that perform the same function form organs. For example, the stomach, the heart and the kidneys are organs. Organs that work together form systems. For example, the oesopahgus, the stomach, the small and the larg intestine form the human digestive system. Different systems form organisms.
1.- What is the function of each part of the cell?
1.- This part controls the cell: _______________
2.- This part protects the cell and lets nutrients in: ______________
3.- This part is mostly made of water: _________________
2.- Order the words from the simplest to the most complex structures:
Organism - Cell - Organ - Tissue - System
3.- Complete the sentences:
( unicellular - cell - membrane - tissue - multicellular - nucleus - systems - organism)
a.- The ... controls the functioning of the cell.
b.- Cells group together to form ...
c.- In ... organisms, the cell performs all life functions.
d.- Organs that work together form ...
4.- Complete the sentences (Organism - Tissue - Organ)