Passing Package
BIOLOGY
LIFE PROCESSES
→ Steps of Photosynthesis:
(i) Absorption of light energy by chlorophyll.
(ii) light energy → chemical energy and water molecules → hydrogen and oxygen.
(iii) Reduction of carbon dioxide to carbohydrates.
→Aerobic respiration:
★ Presence of oxygen
★ More energy released
★ Produce CO2 + H2O + Energy
★ Ex: Plants and Animal
→ Anaerobic respiration:
★ Absence of oxygen
★ Less energy released
★ Produce Ethanol + CO2 + Energy
★ Ex: Yeast
→ Glucose breakdown:
→ Alveoli:
Increase the surface area for gaseous exchange.
→ Stomach functions
★ Gastric glands release hydrochloric acid, pepsin and mucus.
★ Hydrochloric acid creates an acidic medium which facilitates the action of pepsin.
★ Pepsin digests protein.
→Small intestine functions
★ Small intestine is the site of complete digestion of proteins, carbohydrates and fats.
★ Enzymes in the intestinal juice convert
- proteins into amino acids,
- complex carbohydrates into glucose
- fats into fatty acids and glycerol.
★ Digested food is absorbed by the villi present in the walls of intestine.
→ Villi:
★ Finger-like projections called villi.
★ It absorb digested food.
→ Double circulation
Blood flow through heart twice.
Advantages:
Suply more oxygen to body tissue and helps to maintain constant body temperature.
→Blood vessels:
★ Arteries : Carry oxygenated blood
★ Veins : Carry deoxygenated blood
★ Blood capillaries : Exchange of materials.
Difference between arteries and veins
→Nephron:
Structure:
Nephron contains glomerulus, Bowman’s capsule, and a long renal tubule.
Functions:
★Waste materials in the blood are filtered and collected by Bowman’s capsule.
★Glucose, amino acids, salts and water, re-absorbed and urine flows along the tube.
→Xylem:
★ Transport water and minerals
★ Unidirectional
★ Xylem tracheids and vessels transport materials
★ Suction pressure
→ Phloem:
★ Transport food
★ Bidirectional
★ Sieve tube and companion cells transport materials
★ Osmotic pressure
Transpiration: process of removing excess of water from plant body.
Translocation: process of transport of food from leaves to other parts of plant.
→ Excretion in plants
★ Excess of water removed by transpiration
★ Remove oxygen and carbon dioxide gases through stomata
★ Resins and gums get store in old xylem
HOW DO ORGANISMS REPRODUCE?
→ Types of Asexual reproduction:
→ Binary fission:
Ex: Amoeba, Leishmania
→ Multiple fission:
Ex: Plasmodium
→ Fragmentation:
Ex: Spirogyra
→Regeneration:
Ex: Planaria
→ Budding:
Ex: Hydra
→ Spore Formation:
Ex: Rhizopus
→ Advantages of vegetative propagation:
★Early flowering and fruit formation.
★ To grow many plants like sugarcane, roses, or grapes.
★ Genetically similar plants produce.
→ Difference b/w Fragmentation and Regeneration
| Fragmentation | Regeneration |
| The organism breaks-up into smaller pieces upon maturation, each piece develops into new individual | If organism is somehow cut or broken into many pieces, each piece grows into a complete organism |
| Ex: Spirogyra | Ex: Planaria |
→ Sexual Reproduction in Plants
→ Self pollination:
Transfer of pollen grains from anther to stigma of same flower.
→ Cross pollination:
Transfer of pollen grains from anther to stigma of different flower.
→ Changes in flower after fertilization:
★ Zygote →Embryo
★ Ovule → Seed
★ Ovary → Fruit
→ Male reproductive parts functions
★ Testis: Produce sperm and Testosterone hormone
★ Vas deferens: Transfer of sperm
★ Prostate and Seminal vesicles: Secrets fluid which helps sperm movement and provide nutrition.
→ Female reproductive parts functions
★ Ovary: Produce egg and estrogen hormone
★ Fallopian tube: transfer egg
★ Uterus: embryo development
→Placenta
★ Transfer oxygen and food from mother to embryo
★ Transfer waste form embryo to mother.
→ Menstruation cycle
★ Every month the uterus wall becomes thick and spongy.
★ If the egg is not fertilized, it breaks and comes out through the vagina as blood and mucous.
→ Contraceptive methods
★ Barrier method: Condoms, Diaphragm
★ Physical method: Copper T
★ Chemical method: Oral pills, Vaginal Pills
★ Surgical method: Tubectomy(female), Vasectomy(Male)
→ Sexual transmitted disease:
★ Virus: AIDS and Warts
★ Bacteria : Gonorrhoea and Syphilis
CONTROL AND COORDINATION
→Reflex action:
Sudden response to stimulus.
→Reflex arc:
★ Path of reflex action
★ Stimulus →Receptor →Spinal card→ Motor neuron→ effector
→ Synapse:
Gap between two neurons
→ Receptors
★ Photoreceptors in the eyes to detect light.
★ Phonoreceptors in the ears to detect sound.
★ Olfactory receptors in the nose to detect smell.
★ Gustatory receptors in the tongue to detect taste.
★ Tangoreceptors in the skin to detect touch.
→Brain parts function
★ Cerebrum: controls touch, smell, hearing, taste
★ Medulla: controls heart beat, blood pressure, coughing, swallowing, vomiting
★ Cerebellum: controls Body movement, balancing
→Plant Hormones
Plant hormones are chemical substance which control and coordinate the plant bady.
★Auxins: Cell elongation
★ Gibberillins: Growth of stem
★ Cytokinin: Cell division
★ Abscisic acid: Inhibits growth
★ Ethylene: Flowering and ripening of fruits
→Tropic movement:
★ Phototropism: Plant growth response to light.
Ex: Growth of Shoot towards light
★ Geotropism: Plant growth response to gravity.
Ex: Growth of root towards earth
★ Hydrotropism: Plant growth response to water.
Ex: Growth of root towards water
★ Chemotropism: Plant growth response to chemical.
Ex: growth of pollen tube towards ovule
→ Endocrine glands in Human being:
★ Pituitary gland - Growth hormone - controls body growth
★ Thyroid gland - Thyroxin - Controls metabolism
★Pancreas - Insulin - Controls blood sugar level
★ Adrenal gland - Adrenaline - Controls blood pressure and heart beat
★Testis - Testosterone - controls sperm production
★ Ovary - Estrogen - Controls egg production
OUR ENVIRONMENT
→ Food Chain:
Flow of food energy from one organism to the next
Ex:
★ Grass → Deer → Lion
★ Grass → Insect → frog → snake
→ Food web
Group of several interconnected food chains.
→ Trophic level
Steps of food chain where energy is transfer.
→ 10% law
Energy transfer decrease at every trophic level by 10%.
→ Ozone layer
ozone is a O3 molecules.
Formation:
Function:
Protect the earth from UV radiation.
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