Biology Notes 2024 PDF

## DIVERSITY - Five kingdoms classification - **Whittaker** - **Monera** - **Protista** - **Fungi** - **Plantae** - **Animalia** - **Group formed on the basis of:** - Source of Nutrition - Body mode - Cell structure -...

## DIVERSITY - Five kingdoms classification - **Whittaker** - **Monera** - **Protista** - **Fungi** - **Plantae** - **Animalia** - **Group formed on the basis of:** - Source of Nutrition - Body mode - Cell structure - Body organisation - **Taxonomy:** Identification of living organisms. - **Father:** Carolus Linnaeus. - **Virus:** - Non-living. - **Algae:** - Belong to Plantae. - Perform Photosynthesis. - Colour: Green/Blue/Red. - **Carl Woese** - Dividing Monera - **Archaebacteria (Archea)** - **Eubacteria (Bacteria)** - **Charles Darwin:** - Described idea of evolution. - **Hierarchy classification** - Kingdom - Animals, Plant - Phylum - Class - Order - Family - Genus - Species ## ORGANISMS - **Prokaryotes:** - Unicelluar - **Monera**. - **Eukaryotes:** - Unicelluar - **Protista** - Multicelluar - With cell wall - **Fungi** - Cell wall made of chitin (though complex sugar). - Heterotrophic Eukaryotic (depends on others) - **Parasite:** Require a living protoplasm of a host organism for food. - **Saprophytic:** Mode of nutrition in fungi. Feed on dead. - Unable to perform Photosynthesis - **Ex: Yeast, Mould (bread), Mushroom, Aspergillus.** - Fungi - Break down food outside the body. - **Plantae** - Able to perform Photosynthesis. - Without cell wall - **Animalia** - **Monera** - Unicelluar prokaryotes. - Some of them have cell wall. - Some of them do not have cell wall. - **Mycoplasma** (No cell wall). - **Autrophic & Heterotrophic** - **Autrophic:** Self-made- - **Cyanobacteria** (blue-green Algae) - **Ex: Anaebeana.** - Cyanobacteria have chlorophyl present and perform photosynthesis. - **Hetrotrophic:** Defence on others. - **Ex: E. coli, Pseudomonas, Rhizobium, Salmonella, Agrobacterium** - **Come under Monera**: Lactobacillus, Nostoc. - **Protista:** - Organism - Unicelluar Eukaryotic organisms. - **Autrophic & Heterotrophic** - Mode of nutrition. - **Ex: Unicellular Algae, Diatoms, Paramecium, Amoeba, Euglena.** - **Protozoans** - **For locomotion: Flagellum** - **Fungi:** - Cell wall made of chitin. - Heterotrophic Eukaryotic. - Unable to perform photosynthesis. - Examples of fungi. - **Plantae:** - Eukaryotes - Multicelluar - Cell wall - Use chlorophyll. - Able to perform photosynthesis. - Mode of nutrition: Autotrophs. - **Cryptogams:** Non seed producing plant. - **Thallophyta:** - Not have well differentiated body (xylem, phloem) - Vascular tissue - absent - Seeds - absent - Flower/Fruit - absent - Habitat: Aquatic plants. - Plants of this group called - Algae. - **Examples:** Spirogyra, Ulothrix, Cladophora, Ulva, Chara, lichen - **Bryophyta:** - Called Amphibians of the plant kingdom. - Vascular tissue - absent - Seeds/flower - absent - Fruit - absent - Differenitiated to form stem/leaf like structures. - **Examples:** Mosses (Funaria), Marchantia, Riccia. - **Pteridophyta:** - Body design - Differentiated. - Vascular tissue - present - Roots, stem, leaves - Seeds/flower - absent - Fruit- absent - Habitat - Terestrial - They consist of the embryo along with stored food. - **Examples:** Marsilea, Fern, Horse Tails. - **Phanerogams:** Seed producing plant. - **Gymnosperms:** - Plantae - Enclosed seeds - Flower present - Fruit present - Seed present - Vascular tissue present - **Angiosperms:** - Flowering plants. - Plantae - Non-flowering plant - Naked-seeds - No fruit - No flower - **Ex: Monocot:** Cycas, Pines (Pinus), Deodar, Cedrus. - **Gymnosperm:** - Body differ. Terrestrial. - Vascular tissue present. - Fruit - absent - **Examples:** Marsilea, Fern. - **Bryophyta:** - Body differ. - Amphibian. - No V.T. - **Examples:** Mosses, Marchantia, Riccia. - **Thallophyta:** - No body differentiation - Aquatic - No vascular tissue - Seeds/fruit/flower-x - **Examples:** Algae, Spirogyra. - **Plants:** - Do not have differentiated plant parts. - **Thallophyta** - **Bryophyta** - Do not produce seeds. - **Pteridophyta** - Have differentiated plant parts. - With vascular tissue. - Produce seeds - **Phanerogarms** - **Gymnosperms:** Bear naked seeds. - **Angiosperms:** Bear seeds inside fruits. - Have seeds with two cotyledons. - **Dicots** - Have seeds with one cotyledon. - **Moncots** ## ANIMALIA - **Eukaryotes** - **Multicellular** - **Without cell wall** - **Mode of Nutrition:** Heterotrophic. - **Symmetry:** - **Asymmetric:** Unequal parts, can’t divide in equal parts. - **Radial Symmetry:** Dividonly Left & Right, any vertical plane equal (starfish, butterfly). - **Bilateral Symmetry:** - **Body Cavity (Coelom):** - **Acoelomate:** No true internal body cavity or coelom. - **Porifera:** - With holes (pores). - Body not differentiated. - Known as sponges. - **Examples:** Euplectella, Spongilla, Sycon. - Non-motile - Multicellular - Asymmetric - Diploblastic - Acoelomatic (body cavity x) - Marine also. - **Plathyhelminthes:** - Known as Flatworms. - Bilaterally symmetrical - Triploblastic - **Examples:** Tapeworm, Planaria (free-living), Liver Fluke (parasitic). - **Pseudocoelomate:** Fake body cavity. - **Nematoda:** - Cylindrical body. - Bilaterally symmetrical. - Triploblastic. - Fake body cavity (coelom). - **Examples:** Ascaris, Wuchereria. - **Coelomate:** - **Annelida:** - Segmented cylindrical body. - Body differentiated into head & tail. - Bilaterally symmetrical - Triploblastic - Have true body cavity. - **Examples:** Earthworm, Leech. - **Arthropoda:** - Largest phylum in the animal kingdom. - Jointed legs - Bilaterally symmetrical - We differentiate organ (B.C) - Triploblastic - Open circulatory system - **Examples:** Spiders, Butterfiles, Mosquitoes - **Mollusca:** - Kidney like organ - execretory sy. - Bilaterally symmetrical. - Triploblastic - Less segmented body - Well developed organs (B.C) - Open circulatory system - Limbas are present. - **Examples:** Snails & Octopus. - **Echinodermata:** - Radial symmetry, Triploblastic - True coelom cavity - Have hard calcium carbonate skeleton. structure - Free living marine Animals. - **Examples:** Sea Urchins, Starfish. - **Chordata (Proto):** - Bilaterally symmetrical - Triploblastic - Circulatory system is closed type. - Road-like system - **Examples:** Balanoglossus, Herdmania - Marine Animals. - **Vertebrata:** - Have a notochord. - Vertebral column. - Internal skeleton - Bilaterally symmetrical - Triploblastic, coelomic & segmented - **Cyclostomata:** - Body is round & elongated like an eel. - Skin soft & smooth. - 2 chambered heart. - Lateral line acts as a sense Organ - **Examples:** Petromyzon, Maxine. - **Amphibia:** - Lays eggs. - 3 chambered. - Both land & water - Respires through the lungs/skin/their gills. - Gills present - **Examples:** Frogs, Salamanders - Mucus glands in the skin. - **Pisces:** - Body is usually streamlined. - Cold-blooded organisms - Gills help in respiration. - Lays - eggs - Single, closed type of blood circulation. - 2 chambered heart - **Reptilia:** - Cold-blooded - Breathe through lungs - 3 chambered heart - 4 chambered (only crocodiles) - Skin dry, tough, without glands. - **Examples:** Snakes, Turtles, Lizards, Chameleon. - **Aves (Birds):** - Warm-blooded - 4 chambered heart. - Lay eggs. - Breathe through lungs. - **Mamalia:** - Warm-blooded, external ears. - 4 Chambered heart. - Have hair, oil glands, sweat - **Exceptions:** Platypus & Echidna (lay eggs as well as milk). - **In vertebrates -> SER:** - Cell of Liver - Plays a crucial role in detoxification of toxic compounds. ## LIFE PROCESSES - **Nutrition:** - **Autotrophic** - **Chemo-Autotrophic:** - Using chemicals - Few Bacteria. - **Photo-Autotrophic:** - Required: CO2 + sunlight + water. - **Examples:** Plants - **Heterotrophic** - **Holozoic N.** - Engulf food. - Food break down inside the body. - Animals - **Examples:** Amoeba. - **Saprotrophic N.** - Depends on dead & decaying organisms. - Food break down outside the body. - **Examples:** Yeast, Mushrooms, Bread moulds, Fungi. - **Parasitic** - Derive nutrition from plants & animals without killing them. - **Examples:** Cuscuta (Amar-bel), Ticks, Lice, Leeches, Tapeworms - **Amoeba:** - **Ingestion -> Digestion -> Absorption -> Assimilation -> Egestion** - **Holozoic Nutrition:** Taking food - finger like extension. - **Ingestion:** - Food particle. - Nucleus - Pseudopodia (help in capturing of food). - **Digestion:** - Food vacule - **Absorption** - **Assimilation** - **Egestion** - **Nutrition in Human Beings** - **Digestion start from Mouth** - Fluid called saliva in mouth - Saliva contains enzyme called salivary amylase - **Maltose** (complex starch) break down into **Sugar** (simple) - Food-> mouth to stomach through oesophagus (food pipe) - **Alimentary canal:** - **Organs that involve** - **Organ:** - Mouth - Oesophagus - Stomach - Small intestine - Large intestine - **Accessory organs:** - Gall bladder - Liver - Bile - Pancreas - **The small intestine also produces its own enzymes:** - **Maltase:** Hydrolysis of polysaccharides mainly to the - **Lactase:** - **Sucrase:** - **Peptidases:** - **Stomach:** - **Gastric glands:** - **Fun:** Digestion in stomach is taken care. - **Pepsin:** Protein digesting enzyme (incomplete digestion in stomach). - **Mucus:** Protects the inner lining of the stomach. - **Hcl:** - **Pepstin** - **Mucus** - **Sphincter muscle:** - Regulates food from the stomach (acidic) - **Gall bladder:** - **Pancreas:** - **PH: 8.5** - **Pancreatic juice:** - **Small intestine:** - **Complete digestion:** - **Fat** - **Protein** - **Carbohydrate** - **Trypsin enzyme, Amylase, Lipase enzyme** - **Protein digest** - **Small intestine:** - **Villi** - **Herbivores:** - Long small intestine to allow cellulose to digest. - **Carnivores:** - Shorter small intestine. - **Ex:** Tiger, meat. - **Enzymes final convert.** - **Protein:** Amino Acid - **Complex carbohydrates:** Glucose, Glycerol - **Large intestine:** - **Respiration:** - **Breathing process:** Inhaling & exhaling - **Only lungs** - **Physical processes:** - **No energy** - **Respiration:** - **Break down glucose** - **Produce energy** - **All cells** - **Chemical processes:** - **ATP produce.** - **Respiration:** - **Aerobic:** - O2 required - Take place cytoplasm & mitochondria. - Complete break down of glucose. - End process: CO2 + H2O - **Anaerobic:** - O2 not required or lack. - Cytoplasm only. - **Yeast** - Incomplete break down of glucose. - End products: CO2, Alcohol, Lactic Acid. - **Absence of O2 (in yeast):** Anaerobic R. - Ethanol + CO2 + Energy (2-carbon) - **Lack of O2 (muscle cell):** Lactic acid + energy (3-carbon) - **Presence of O2 (mitochondria):** Aerobic resp - CO2 + H2O + Energy - **Inhalations:** - Ribs lift up - Diaphragm flat. - Volume of lungs increase. - **Exhalation:** - Ribs downward. - Diaphragm dome shape. - Volume of lungs decrease. - **Haemoglobin** present in the RBC (very high affinity for oxygen) - If the alveolar surface spread out, it covers about 80m² (CO2 is more soluble in water than O2). - **Transportation:** - **Plants:** - Transportation done by vascular tissue. - **Humans:** - Transportation by circulatory system. - **Blood:** - Carry everything also (salt). - **Plasma:** 55% of blood (suclecell anemia, RBC) - Fluid medium, called plasma. - Content: Protein, Hormones. - **Blood cells:** 45% - **WBC (Leukocyte)**: Large, colorless, help? blood clotting. - Shaped: Circular, disc shaped. - Colour: Red because of hemoglobin. - Common name: Erythrocytes - **Cockroach:** 13 chamber heart - **Octopus:** 3 heart. - **Arteries:** - Have thick, elastic walls - Flow of oxygenated blood. - Located: Deep in the muscle. - Have very thick wall. - Blood flow: Heart - -> Body. - **Veins:** - Not need thick walls. - Flow of deoxygenated blood. - Veins present surface of the body. - Have thin walls. - Blood carry: Towards heart. - **Coronary artery:** - Carries blood to heart muscle. - **Capillaries:** - Connection b/w arteries and veins - **Carotid artery:** - Supplies oxygenated blood brain to eyes. - **Subclavian artery:** - Providing blood head & neck. - **Heart:** - **Left atrium:** - Receives oxygen-rich blood from the lungs and pumps it to the left ventricle. - **Left ventricle:** - Left ventricle pumps the oxygen-rich blood to the body. - **Right atrium:** - Receives deoxygenated blood from the body & pumps it to the right ventricle. - **Right ventricle:** - Pumps the deoxygenated blood to the lungs. - **Veins:** - Carry deoxygenated blood towards heart. - **Arteries:** - Carry oxygenated blood away from heart. - **Pulmonary arteries:** - Only arteries can carry deoxygenated blood heart to lungs. - **Pulmonary veins:** - Only veins can carry oxygenated blood, lungs to heart. - **Blood Pressure** - Force that blood exerts against the wall of a vessel - BP: Arteries) veins - **Systolic pressure:** p.f blood inside artery during ventricular systole (contraction). - Normal S.P - about 120 mmHg - **Diastolic pressure:** Pressure in artery during ventricular diastole (relaxation). - Normal D.P - 80 mmHg - **Lymph:** - Colourless & contains less protein. - Absorbed fat from intestine - Drains excess fluid from extracellular space back into the blood. - **Excretion:** - **Excretory stem of human beings:** - Pair of kidneys. - Pair of ureters - Urinary bladder - Urethra - **Kidney:** - PH maintain - Located: In the abdomen. - Urine produce in the kidneys. - **Ureters:** - **Urinary bladder:** Urine stored. - **Urethra** - **Each kidney has 1 million nephrons.** - **Filtration unit of our body:** - **Bowman’s capsule:** Cup shaped end of a coiled tube. - **Nitrogenous waste:** - Urea - Uric acid - CO2 - Excess water - **Guttation:** - Night. - Water loss in the form of water droplets. - **Transpiration:** - Day. - Loss of water in form of water vapour. - **O2 waste in plants:** - Plant waste is stored in cellular vacuoles. ## REPRODUCTION - **Chromosomes:** Become half during gamete formation. - **Male:** 46, sperm cell format - 23. - **Female:** 46, egg cell format - 23. - **Zygote:** 46. - **Meiosis:** - Single cell. - **Asexual:** - Only one parent is required. - No gamete - No fertilizer - No zygote. - **Sexual:** - Two parent needed. - Gamete format - Fertilization - Zygote (multiple cell) - **Embryo** - The DNA in the cell nucleus is the information source for making proteins. - The basic event in reproduction is the creation of a DNA copy. - **DNA copies:** - Will be similar but may not be identical. - Some variation each time. - Useful for time survival of species. - **Fission:** Spliting or division - **Binary:** - Organism split into two parts. - **Longitudinal binary fission:** - **Transverse binary fission:** - **Irregual binary fission:** - **Horizontal spitting** - **Leishmania:** Which cause Kala Azar, split longitudinally. - **Paramecium.** - **Amoeba.** - **Multiple fission:** - **Malarial parasite.** - **Plasmodium.** - **Cytoplasmic stand, mucilage, nucleus, cell wall, plasma membrane, vacuole, pyrenoid.** - **Fragmentation (Ex: Spirogyra):** - Imply breaks up into smaller pieces upon maturation. - These pieces or fragment grow into new individuals. - **Budding:** - **Bud:** Develops as an outgrowth due to repeated cell division at one specific site. - These buds develop into tiny individuals and when fully mature. - **Examples:** Hydra, yeast, planaria. - **Spore formation:** - Multicellular organisms (Fall: Fungi) - Reproduce by spores. - **Bob-on-a-stick structures:** Involved in reproduction called: sporangia. - **Ex: Rhizopus** - **Reproductive part:** - **Sporangia:** Blob like structure. - **Contain:** Spores or cells. - **Non reproductive part:** - **Hyphae** - **Spores** - **Regeneration:** - Individual is somehow cut or breaken up into many pieces. Many of these pieces grow into sperate individuals. - **Examples:** Planaria, Lizard, Hydra. ## Vegetative Propagation - Used in method: - Layering - Grafting to grow many plants. - **Examples:** Sugarcane, Bryophyllum, Potato, Grapes. - **Natural vegetative propagation:** - **Stem:** Turmeric, Ginger. - **Runners/stolon:** Grass runners, strawberry. - **Bulbs:** Onion, Lily. - **Vegetative part:** - Not involved in sexual reproduction. - Bud produced in the notches along the leaf margin & Bryophyllum fall on the soil & develop into a new plant. - **Leaf of Bryophyllum with buds** ## Sexual Reproduction - **Flower:** - **Reproductive part:** - **Female part:** Pistil/Carpel - **Stigma** - **Style** - **Ovary** - **Pollen grain** - **Stigma** - **Male germ cell** - **Pollen tube** - **Female germ cell** - **Male part:** Stamen - **Filament** - **Anther** - **Pollen grain** (produced by Anther) - **Male gamet** - **Stamen:** - Produce pollen grains that are yellowish in colour. - **Bisexual:** - Contains both stamens + pistil (male) (female) - **Examples:** Hibiscus, Mustard, Pea. - **Unisexual (either one):** - **Staminate:** Male reproductive part - **Pistilate:** Female reproductive part - **Examples:** Papaya, Watermelon. - **Pollination:** - **Cross:** - One flower to another. - Through: Wind, Animals, Water. - **Self:** - Same flower, pollination. - **Pollen:** Needs to be transferred from the stamen to the stigma. - **After fertilization:** - **Egg converted:** - **Zygote:** Single cell - **Embryo:** Multiple cell. - **Seed:** Ovule converted. - **Fruit:** Ovary grows rapidly & ripens to form fruit. ## Sexual Reproduction in Human - **Puberty:** - **Boys:** - Facial hair growth - Thinner hair, also in legs. - Skin oily - Genitals growth. - Voices deepening. - **Girls:** - Hair: underarm & pubic. - Breast development - Darkening skin at nipples at tips of breasts. - Mensuration cycle. - Voice shriller. - **Leydig cells or interstitial cells:** - Present: B/w the seminiferous tubules. - Secrete hormone Testosterone. - **Ureter:** - **Seminal vesicle:** - **Bladder** - **Prostate gland:** - **Penis:** - **Urethra:** - **Male Reproductive system:** - **Testes:** - Formation of sperms & germ cells. - Located outside the abdominal cavity in scrotum (pouch). - Sperm formation requires a lower temp. than normal body temp. - **Sperms:** - Are produced by seminiferous tubules and mature in the epididymis. - **Vas deferens:** - Transports mature sperm to the urethra. - **Urethra:** - Common passage for both the sperms and urine. - **Along the path of the vas deferens, in sperm:** - **Prostate gland & seminal vesicles:** - Add their secretion (nutrition) - **Placenta:** - The embryo gets nutrition from the mother’s blood with the help of a special tissue. - **Villi:** Provide large surface area for glucose and O2 to pass from the mother to the embryo. - **The child is born as a result of rhythmic contractions of the muscles in the uterus.** - **Female Reproductive system:** - **Main reproductive organs:** Pairs of ovaries. - **Ovaries:** - One egg is produced every month by one of the ovaries. - Egg is carried from the ovary to the womb through a thin oviduct. - **Uterus:** - Two oviducts unit into an elastic bag like structure. - **Sperm + egg:** - Single cell - Zygote - Fertilized egg - Embryo: Divide by multiple cells - Foetus - Blood/ mucous - **Female ovary:** - Produce egg once a month. - Uterus wall become thick. - **Egg fertilized:** - Pregnancy. - **Not fertilized by sperms:** - Egg + Uterus wall + blood vessels. - **Come out through the vagina:** Rupture. ## Control & Coordination - **Nervous system:** - **CNS:(central nervous system)** - Brain - Spinal cord - **PNS (peripheral nervous system):** - Spinal nerves - Cranial nerves (11). - **Gustatory receptors:** Detect taste - **Olfactory receptors:** Smell - **Thermoreceptors:** Skin - **Photoreceptors:** Eyes - **Sensory receptors:** Ears - **Inner ear:** Body balance - **Dendrite:** Receive impulses from other neurons. - **Nucleus** - **Axon (soma)** - **Cell body** - **Dendrite point** - **Neuron** - **Nerve ending** - **Synapse:** Gap between two neurons - Between two neurons - Neurotransmitter. - **Types of neurons:** - **Sensory neuron:** - Carry information (afferent) to brain. - **Receptor** - **Motor neuron:** - Carry information (efferent) from brain cells to effector organ. - **Interneuron:** - Sensory neurons + motor neurons. - **Reflex action:** Sensory neuron - **Receptors:** Heat/pain, receptors in skin. - **Effector:** Muscle in arm. - **Stimulus receive:** - **Receptor** - **Sensory neuron** - **Relay neuron (in spinal cord):** - **Motor neuron:** - **Effector:** - **Response** - **Spinal cord (CNS):** - Message to brain - **Motor neuron** - **Relay neuron:** Interneuron. - **Brain:** - Is not involved in reflex action but info will reach brain. - **Vertebral column:** - Backbone. - Protects the spinal cord. - **Brain:** - **For brain:** - **Pituitary gland:** - **Hypothalamus:** - **Hind Brain:** - **Receive signals** from sensory organs: - Eyes, ears, skin, nose, tongue - Voluntary movement. - Past experience. - **Fore brain:** The main thinking part of the brain. - **Regulate the senses:** - Sight - Smell - Hearing - **Brain:** - **Cerebrum** - **Brain protected by:** - Cerebrospinal fluid. - *The meninges:* - Dura mater - Arachnoid - Pia mater - **Mid brain:** - Connect for brain - Hind brain - Controlled: involuntary action. - **Pons:** - Sleep cycle - Breathing rate. - **Mid brain:** - Connect for brain. - Hind brain. - Controlled: involuntary action - **Hind brain:** - Cerebellum: - Balance of body - Walk in a straight line - Riding bicycle - Picking up pencil - **Medulla** - Control involuntary action. - Blood pressure. - Salivation. - Vomiting - Heart beat. - Cough. - Respi. rate. - **Spinal cord** - **Plant hormones:** - **Growth promoters:** - **Auxin:** - Helps in growth longer in plant tissue. - Light coming one side, auxin diffuses towards the shady side of the shoot. - Plant to bend towards the light. - **Gibberellin:** - Help in growth of stem - Germination - Flowering - delay aging - **Cytokinins:** - Help in cell divisions. - **Growth inhibitors:** - **Abscisic Acid:** - Inhibits growth. - Wiltering of leaves. - Dormancy of buds/seeds. - **Ethylene (ethyl):** - Gaseous hormone which causes ripening of fruits. - **Hormones in animals:** - If contraction of the diaphragm and rib muscles: - Breathing rate increases. - **Gland:** - **Thyroid gland:** - Iodine is necessary to make thyroxin hormone. - Idione: Synthesis of thyroxin - Iodine deficient: - Symptoms: Goitre disease (swollen neck) - **Pituitary gland:** - Stimulates growth in all organs. - Deficiency: Hor in childhood. - It leads to dwarfism. - **Pineal gland:** - Regulate sleeping pattern. - **Pancreas:** - **Insulin:** Help in regulating blood sugar level. - **Only gland:** exocrine & endocrine - **Adrenal gland:** - Regulate: - Heart beat. - **Testes:** - Sperms - **Male** 12-10 years (puberty). - **Secretion of testosterone** - **Ovaries:** - Ovum - **Female** - **Secretion of estrogen.** - **Growth independent moments:** - **Nastic movements:** Movements which are not growth related. - **Thigmonastic movement:** Movement in response to touch. - **Ex: Touch-me-not plant:** Belongs to Mimosa. - **Growth related movements in plants:** - **Tropic movements:** Growth related. - **Phototropism:** Response in light. - **(+ve) photo:** Growth towards the light: Stem, Shoot - **(-ve) photo:** Growth away from the light: Roots. - **Geotropism:** In response to gravity. - **(+ve) geotropism:** Roots - **(-ve) geotropism:** Stem. - **Thigmotropism:** In response to touch an object. - **Pineal gland, Pituitary gland. Thyroid gland, Thymus, Adrenal gland** ## Heredity and Evolution - **Genetics:** Study of heredity & variation. - **Father of Genetics:** G.J Mendel. - **Worked on pea plant.** - **Traits:** - **Somatic variation:** Acquired traits (after birth). - Tattoo - Driving - **Gametic variation:** Inherited (by birth). - Hair colour - Eye colour - Skin colour. - **When cell division:** - **DNA scattered** in Chromatin - **Chromosomes:** Coild/Condensed of DNA, histone protein. - **Free earlobe:** - **Eye colour:** - **Hair colour:** - **Closed earlobe:** - **Alleles:** Gene ki variety. - **Maternal chromosomes DNA** - **Paternal chromosomes ONA** - **Gene:** - **Brown** - Dominant - **Blue** - Recessive - **Alleles:** - **Stronger gene will win (dominant)** - **Dominant allele:** - Denoted by capital letter (T). - **Recessive allele:** - Denoted by small letter (t). - **Pea:** Pisum sativum - **Flower:** - **Violet flower (V):** Dominant. - **White flower (w):** Recessive. - **Zygote:** - **(i):** - **V/V:** Both are dominant. - **Homozygous dominant condition (pure condition).** - **Violet colour** - **(ii):** - **w/w:** Both are recessive. - **Homozygous recessive condition (pure condition).** - **White colour** - **(iii):** - **V/w:** One Dominant + one recessive. - **Heterozygous condition (hybrid)** - **Violet colour** - **Next