LIFE PROCESSES
Life Processes- these are the basic functions performed by living organisms for their survival and body maintenance.
It includes Nutrition, Respiration, Transportation, Excretion etc.
Nutrition- There are two types of nutrition: autotrophic and heterotrophic.
Photosynthesis- It is the process by which green plants make their own food with the help of CO2 and H2O in the presence chlorophyll and sunlight.
Raw materials for photosynthesis are carbon dioxide and water.
Site for photosynthesis is chloroplast in the leaf . Chloroplast contain green colour pigment called chlorophyll.
Main events of photosynthesis are:
1. Absorption of light energy by chlorophyll. 2. Conversion of light energy to chemical energy and splitting of water molecules into 3. hydrogen and oxygen. 4. Reduction of carbon dioxide.
- Stomata- stomata are tiny pores are present on the surface of the leaves. Exchange of gases and transpiration takes place through stomata.
- The opening and closing of stomata is a function of the guard cells.
- Heterotrophic Nutrition- this is of three types: Holozoic(eg- amoeba, animals), Saprophytic(eg- fungi) Parasitic(eg- Cuscuta).
- Nutrition in amoeba- Amoeba takes in food using temporary finger-like extensions of the cell surface(Known as pseudopodia), which fuse over the food particle forming a food vacuole.
- Human digestive system- In humans, digestion begins the mouth and gets completed in small intestine.
- Respiration- It is a process in living organisms involving the production of energy.
- There are two modes of respiration: aerobic(in the presence of oxygen) and anaerobic(in the absence of oxygen).
- Human respiratory system- It involves the passage of air through the respiratory system.
- Mechanism of breathing- It involves two processes: Inhalation and exhalation.
- In human beings, oxygen is transported by haemoglobin. Haemoglobin is respiratory pigment present in RBCs, which have a very high affinity for oxygen.
- carbon dioxide is more soluble in water. than oxygen and hence is mostly transported as dissolved form in our blood .
- Terrestrial organism uses atmospheric oxygen for respiration.
- Aquatic organisms uses oxygen dissolved in water.
- Respiration in plants- Gaseous exchange occur through stomata in leaves, lenticels in stems, general surface of the roots and transpiration.
- The Circulatory system in human beings consists of: a circulatory medium (blood and lymph), blood vessels ( veins, arteries and capillaries) and heart.
- Humans have double circulation. In this, the blood travels twice through the heart in one complete cycle of the body.
- Pulmonary circulation- Blood moves from the heart to the lungs and back to the heart .
- Systemic circulation-Blood moves from the heart to the rest of the body and back to the heart.
- BLOOD Is a fluid connective tissue. It comprises of four components -Plasma, RBCs WBCs, and platelets.
- LYMPH is a yellowish fluid that escapes from the blood capillaries into the intercellular spaces. lymph flows from the tissue to the heart assisting in transportation an destroying germs.
- TRANSPORTATION in plants occurs via xylem and phloem.
- XYLEM carries water and minerals from roots to other parts of plants while PHLOEM carries food from leaves to other parts of the plants.
- TRANSPIRATION is the process by which plants lose water in the form of vapours.
- TRANSLOCATION is the transport of food from leaves (food factory) to different parts of the plants.
- The process the removal the harmful metabolic wastes from the body is called EXCRETION.
- EXCRETORY SYSTEM of human beings includes a pair of kidneys, a urinary bladder, a pair of ureter and a urethra.
- KIDNEY removes waste product from the blood i.e., urea which is produce in the liver.
- NEPHRON is the functional and structural unit of kidney.
- The urine formation involves three steps: Glomerular filtration, tubular re-absorption and secretion.
- Hemodialysis- It is the process of purifying blood by an artificial kidney. It is meant for kidney failure patient.
IMPORTANT CONCEPTS:-
FUNCTIONS OF BLOOD VESSELS-
1.ARTERIES- They carry blood away from the heart to various organs of the body.
2.VEINS- They collect blood from different organs and bring it back to the heart.
3.CAPILLRIES- Exchange of material between the blood and surrounding cells takes place across the thin walls of capillaries.
DIFERRENCE B/W ARTERIES AND VEINS:-
Arteries-1.They are thick walled.
2.they have no valves
3.carry oxygenated blood except, pulmonary artery.
Veins- 1. They are thin walled.
2.they have halves.
3.carry deoxygenated blood except pulmonary vein.
GLANDS AND THEIR SECRETIONS:-
1.Salivary glands- Saliva
2.Gastric glands- Gastric juice, HCL, mucus and pepsin
3.Liver- Bile juice
4.Intestinal glands- Intestinal juice
5.Pancrease- Pancreatic juice, trypsin, lipase, and amylase
AEROBIC AND ANAEROBIC RESPIRATION:-
Aerobic- 1.It takes place in the presence of oxygen.
2.Product obtained are CO2 and H2O.
3.More energy is produced.
Anaerobic- 1. It takes place in the absence of oxygen.
2. products obtained vary.
3. Less energy is produced.
→ In humans, air takes the following path:
Nostrils↣ Nasal passage ↣ Pharynx ↣ Larynx ↣ Trachea ↣ Bronchus ↣ Bronchiole ↣ Alveolus.
Photosynthesis process:-
Glucose breakdown:-
Leafe cross-section:-
Stomata:-
human heart:-
Respiratory system:-
Human alimentary canal:-
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