Chapter 6 – Life Processes || Class - 10th || Science || - APNA MATH CLASSES

Nutrition in Plants and Animals

Nutrients: Carbohydrates, proteins and fats are the main nutrients and are called macronutrients. Minerals and vitamins are required in small amounts and hence are called micronutrients.

Modes of Nutrition

      1. Autotrophic Nutrition.
      2. Heterotrophic Nutrition.

1.   Autotrophic nutrition (Auto =self and trophos = nourishment) E.g. Plants, Algae, blue green bacteria.

Process – Photosynthesis (Photo=light; Synthesis= to combine)
Raw materials- (i) Carbon dioxide (ii)Water
Equation- 

6CO2 + 6H20 ------SUNLIGHT + CHLOROPHYLL -----> C6H12O6 + 6O2             
 
Energy conversion- Light/Solar energy to Chemical energy

Factors for Autotrophic nutrition -

(i) Carbon dioxide
(ii) Water
(iii)  Light
(iv) Temperature

Events/ Steps of photosynthesis-

(i)   Absorption of light energy by chlorophyll
(ii) Reduction of Carbon dioxide to Carbohydrate

Gaseous exchange-

(i) Gas used- Carbon dioxide
(ii)  By product - Oxygen

Source of raw materials-

(i)  Water & Minerals - Soil

Heterotrophic Nutrition – Life Processes Class 10 Notes

Heterotrophic nutrition can be further divided into three types, viz. saprophytic nutrition, holozoic nutrition, and parasitic.

The digested food is then ingested by the organism. All the decomposers follow saprophytic nutrition. 

Parasitic Nutrition: The organism which lives inside or outside another organism (host) and derives nutrition from it is known as parasites and this type of mode of nutrition is called parasitic nutrition. For example Cuscuta, tick etc.

Nutrition in Amoeba

1. Amoeba feeds by holozoic mode of nutrition.
2. The engulfed food gets enclosed in a food vacuole.
3. As the food vacuole passes through the cytoplasm, digestion, absorption and assimilation take place.

Nutrition in Paramoecium

1. Paramoecium also exhibits holozoic nutrition.

1. A food vacuole is created enclosing the food.

Nutrition in Human Beings

The alimentary canal is divided into several parts, like oesophagus, stomach, small intestine, large intestine, rectum and anus.

Structure of the Human Digestive System:The human digestive system comprises of the alimentary canal and associated digestive glands.

• Alimentary Canal: It comprises of mouth, oesophagus, stomach, small intestine and large intestine.
• Associated Glands: Main associated glands are
  • Salivary gland
  • Gastric Glands
  • Liver
  • Pancreas

(i) Mouth: Intake of whole food.

(ii) Teeth: Chewing/grinding of food.

(iv) Salivary Glands: Secrete saliva + Mucus (It is a sticky, gelatinous material that lines your lungs, throat, mouth, nose, and sinuses.) + Starch is converted into glucose by saliva (Salivary amylase)

(vii) Small Intestine: The small intestine is the site of the complete digestion of carbohydrates, proteins and fats.

(a) Walls of small intestine secrete intestinal enzyme which convert Carbohydrates into glucose, fats in fatty acid + glycerol and Proteins into amino acids.

(c) It receives the secretions of the liver and pancreas.
→ The food is acidic which is made alkaline for the pancreatic enzymes to act.

(viii) Large Intestine:
(a) Absorb excess of water.

Stomata – Life Processes Class 10 Notes

Functions of stomata

• Exchange of gases, O2 and CO2.
• Loses a large amount of water (water vapour) during transpiration.

Opening and closing of stomatal pores:

• The opening and closing of stomatal pores are controlled by the turgidity of guard cells.

Human Respiratory System

Passage of air through the respiratory system:

→ Nostril: Air is taken into the body.

→ Nasal Cavity:  It is lined with hairs and mucus membrane.
→ Trachea: Pharynx splits into trachea and esophagus. It connects the larynx (or voice box) to the bronchi of the lungs.

→ Bronchi: They are the main passageway into the lungs.