What are the different types of teeth?
Teeth are the organs that perform mechanical digestion in the mouth or oral cavity. There are different types of teeth some of them are incisors, canines, first molars, and second molars. Each tooth has four types of surfaces.
- Milk teeth: at about 6 months of age the first set of teeth appears. These teeth are called milk teeth, which remains, till the age of 6.
- Permanent teeth
About at the age of 7 years, the milk teeth gradually fall and are replaced one by one by the permanent teeth. These teeth remain until the age when they start falling again.
Location of teeth
There are about 32 permanent teeth in human beings in both of the jaws. Teeth are embedded in jaw sockets. There are 16 teeth in the upper jaw and 16 in the lower jaw.
Structure of teeth
Each tooth consists of three parts.
It is the parts of the tooth which are above the gum level, it is the biting chewing surface o0f tooth.
It is the part of a tooth that is surrounded by the gum.
The root is the part of the tooth that is embedded in bone.
The outer surface of the crown is covered by a very hard white substance, known as the enamel. It is non-living and protects teeth. It also gives a lustrous appearance to teeth.
The inner portion of the enamel is called the dentine. It is not as hard as the enamel.
- Pulp cavity
There is a cavity inside the dentine, which is known as the pulp cavity.
The pulp cavity is filled with soft connective tissue called the pulp. It also contains the nerves and blood vessels that supply oxygen and food to the growing tooth.
The root of each tooth is covered with a hard material called cement. The tough fibers of periodontal membranes attach the cement to the bone to fix them firmly in the jaw socket.
A diet that contains all of the nutrients required by the body is called a balanced diet.
Composition of a balanced diet
Balanced diet-contains carbohydrates, fats, proteins, vitamins, and minerals in proper proportion according to the requirement of the body.
Recommendations for a balanced diet
An average adult can get the necessary energy as 50% from carbohydrates.
Fats contain soluble vitamins and fatty acids. So the vitamins are available for the body. Fatty acids are also high energy suppliers. Thus fat must be included in a balanced diet.
Adults are recommended to get 1gm of protein per kg of body weight daily, while the infants should get 2gm/kg from birth to six months. It is also suggested that 60% of daily intake should have animal proteins because it contains the more important amino acids
The process in which food is calla in the mouth and them the body of the animal is called “ingestion”.
Mechanism of ingestion
- Food is taken in the mouth cavity which is also known as the buccal cavity.
- Food is cut known into smaller pieces by the teeth.
- There are salivary glands in the mouth that secrete saliva.
- Saliva mixes with small pieces of food and helps it to swallow.
- These saliva mixed food particles are easily digestible by the action of enzymes.
The process of breaking the food mechanically into smaller pieces is called mechanical digestion i.e. the breaking of food into smaller pieces in the mouth.
The process in which food is mechanically broken down into smaller chemical compounds is known as the chemical digestion”. Like the breakdown of food by the action of enzymes.
Importance of chemical
Natural and artificial fertilizers are the minerals nutrients that are the source of inorganic requirements of the plants. Inorganic fertilizers provided minerals ions for the successive production of the crop. These minerals are obtained directly or indirectly from the soli. Fertilizers are used to add mainly three elements to the soli in the inorganic form these three elements are nitrogen (N) phosphorous (P) and potassium (K).
Modern commercial fertilizers
Modern commercial inorganic fertilizers are often designated by their N-P-K percentages e.g. the widely used garden fertilizers called 5-10-contains 5%, 10% P and 5% soluble K by weight.
Addition of nitrogen to the soli
Nitrogen is also added to the soil as ammonium nitrate or ammonium sulfate. Phosphorus and potassium are added in the form of superphosphate and potassium chloride, respectively.
What is the importance of photosynthesis?
Excess food made by photosynthesis is stored in the plant body in various ways. It depends upon their environment, age and seasons. It is stored in different parts of the plant such as root, stem, and seed, etc.
Photosynthesis releases oxygen in day time which is used by all the organisms is respiration.
- CARBON DIOXIDE
Photosynthesis reduces CO2 in the atmosphere.
- CARBON CYCLE
Photosynthesis helps in maintaining the carbon cycle.
- COOLING EFFECT
It is a property of CO2 to absorb the heat of the sun. If Photosynthesis does not occur for some reason, CO2 gas produced by the burning of fuels shall accumulate in the atmosphere. Our earth will warm up due to the absorption of heat by CO2
Which minerals are required by the plants beside C, H, and O?
Minerals required by the plants
There are certain other minerals which are also required by the plants. Some of them as follows.
Function: nitrogen is present in amino acid, the building blocks of protein which are essential for protoplasm.
Absorption: it is found in the soil as nitrates or ammonium salts and is absorbed by the plants in dissolved form.
Function: phosphorous is an important element present in the ATP, nucleic acid, cell-wall, NADPH2, and other important compounds.
Absorption: it is absorbed in the form of soluble phosphates, by the plants.
- Sulfur (s)
Function: it is a component of some amino acids.
Absorption: it is found in the form of sulfates in the soil, and absorbed by plants through their roots.
Function: magnetism is an important constituent of chlorophyll, which is the essential pigment of photosynthesis. It is also essential for fats synthesis.
Absorption: it is present in the soil in water-soluble carbonates, and absorbed through root hairs of the plant.
Function: cytochrome is an important compound involved in c=electron transport which contains iron.
Absorption: plants absorbs iron through their roots from the soil