This PSEB 7th Class Science Notes Chapter 2 Nutrition in Animals will help you in revision during exams.
PSEB 7th Class Science Notes Chapter 2 Nutrition in Animals
→ Animals do not make their own food like plants. They get their food directly or indirectly from plants.
→ Animals eat complex foods and then break them down into simpler substances.
→ Different animals require nutrients, different ways of consuming food, and different ways of using food in the body.
→ Those who eat only plants are called vegetarians.
→ Animals that only feed on other animals are called carnivores.
→ Animals that eat both plants and other animals are called omnivorous animals.
→ Different types of animals have different ways of getting food.
→ There are three types of nourishment:
- Decomposer nutrition
- Parasitic nutrition
- Animal nutrition
→ During animal nutrition, complex food is transported to the body where it is broken down into simple soluble substances (compounds) with the help of enzymes, which are absorbed by the body.
→ Five stages during the process of receiving food are:
- Food intake
- Digestion
- Absorption
- Self-adaptation
- Excretion
→ The human digestive system includes the mouth cavity, food pipe, stomach, small intestine, large intestine, Rectum, and Anus.
→ There are four types of teeth in the human mouth:
- Incisors
- Canines
- Pre-molars
- Molars teeth
→ Food is digested starting from the mouth and up to the small intestine.
→ Digested food is transmitted through the blood to different parts of the body.
→ Absorption of water and some salts occurs in the large intestine.
→ Undigested and unabsorbed food remains in the rectum in the form of feces and is then excreted through the anus.
→ Carnivores: Animals that only feed on other animals are called carnivores.
→ Omnivorous: Animals that eat plants and other animals as food are called omnivorous animals.
→ Eating: The act of taking food into the body is called eating.
→ Digestion: This is the biological process during which complex substances are broken down into simpler substances. Enzymes (chemicals) that leak from the glands in the body help in this digestive process. Digestion starts from the mouth cavity and ends in a small intestine.
→ Absorption: This is the stage of food acquisition in which the digested food is absorbed through the inner walls of the small intestine.
→ Excretion: Undigested food passes out of the oesophagus. This process is called excretion.
→ Mouth cavity: The food received through the mouth then goes into the mouth cavity. It is the part that comes after the teeth area.
→ Enamel: A strong protective substance on the teeth is a layer of enamel.
→ Food Pipe: It is the longest part of the oesophagus, extending from the mouth to the anus. Here enzymes break down complex food into simple molecules.
→ Gallbladder: This is a pouch that sits just under the liver, it stores the bile produced by the liver.
→ Caecum: A diaphragm-like structure between the small intestine and the large intestine is called the caecum organ.
→ Bile Juice: The liver is the largest gland of our body from which leakage occurs which accumulates in the gallbladder. This leakage is called bile juice.
→ Ruminants: Grass-eating animals such as cows, buffaloes, are called ruminants.
→ Automation: Food absorbed by the intestines is transported through the blood to different parts of the body. This action is called automation.