REPRODUCTION IN ORGANISMS: Key Points

Life Span: Period frm birth to natural death

Life span not related to size (e.g. mango – short; peepal – long)

Reproduction significance: Continuity of species

Factors on which mode of reproduction depends:  habitat, internal physiology etc.

Cell div mode of rep in unicellular org.

In favourable condition – Binary fission: In amoeba & paramecium (two equal halves) In Unfav conditions: Encystation & Sporulation (formation of minute Amoeba or Pseudopodiospores)

Budding: yeast (2 unequal halves)

In Fungi & Algae: Asexual rep through spores: Types: Zoospores – motile; zygospores – non motile Conidia – in Penicillium; Gemmules – in Sponges Fragmentation – Hydra

Water Hyacinth (terror of Bengal), high rate of veg propagation.

Veg propagules: Potato: Buds (eyes), Banana & Ginger: Rhizome;  Bryophyllum: Adventitious buds on leaf margins…… Key feature: NODE

In simple org: asexual rep in fav conditions; sexual in unfav (provides variations, enables protection by hard seed coat) In higher org: sexual rep common, asex rare. In animals only sexual

Sexual Rep: Elaborate, Complex & Slow. Offspring not identical to parents

Common pattern of sexual rep: Complete juvenile/vegetative (in plants) phase Beginning of rep phase (flowering in plants) senescent phase Length of the 3 phases variable in different organisms Hormones responsible for transition between 3 phases. Unique: Bamboo perennial but flowering once in lifetime Strobilanthus kunthiana once in 12 yrs.

Animals: e.g. birds seasonal breeders in nature (in captivity; exploited) Placental Mammals: Cyclical changes in ovaries & Hormones Non primate mammals: Oestrous Cycle Primate mammals: Menstrual cycle

Events: Pre-fertilization, Fertilization & Post fertilization

Gametogenesis: Male & Female, haploid, may be homogametes (isogametes) or heterogametes. Male: antherozoid or sperm; female: egg or ovum

Sexuality in plants: Unisexual/Dioecious/Heterothallic e.g. papaya, date palm OR Bisexual/Monoecious/Homothallic Male: staminate; Female: Pistillate If make and female flower on different plants: dioecious If male & female flower on same plant: Monoecious

Sexuality in animals: Bisexual (Hermaphrodite): Earthworm, Sponges, tapeworm & leech Unisexual: Rest

Gamete Formation: Haploid Parents body may be haploid: e.g. fungi, algae, Bryophytes. Produce gametes by mitosis Diploid: e.g. pteridophytes, Gymnosperms, Angiosperms and all animals. Produce gametes by Meiosis

Site of meiosis in diploid organisms: Meiocytes (gamete mother cells)

Gamete Transfer: organisms where both male & female gametes: fungi & Algae To compensate for loss during transfer, male gametes produced in large numbers.

In bisexual flowers – self fertilization In unisexual flowers – cross fertilization, so pollination important.

Fertilisation/ Syngamy: Dev of new organisms without fertilization : Parthenogenesis Seen in Rotifers, Honeybees & some Lizards. Site of Fertilization: Outside (External), Inside mother’s body (Internal) fertilization. Disadvantages of Ext Fertilization: Gametes can be destroyed by predators. Technique to avoid this – large number of gametes released.

Post Fertilization Events: Formed in medium (external fert)/ In Mother’s body (Int Fert) Types of development; Undergoes period of rest- fungi & Algae  (develops thick wall to protect from desiccation and damage) Undergoes Meiosis – Haplontic life cycle – forms haploid spores Forms embryo

Embryogenesis: Zygote                  Cell Division & Cell Differentiation                                                         Embryo Oviparous vs Viviparous Parts of flower after fertilization: Petals: wither & fall Sepals: Wither and Fall (Exception- Brinjal, Tomato) Pistil: Remains attached Stamen: wither & Fall Ovary: Fruit (Wall of fruit – Pericarp)

And now some questions:

1. Why unicellular organisms are considered immortal?
2. Why progeny of asexual reproduction called Clones?
3. What are vegetative Propagules?
4. Characterize: Veg, rep & senescent phase in annual, biennial & Perennials
5. Differentiate: Seasonal & Continuous Breeders

BIOTECHNOLOGY

IMPORTANT TOPICS

BOARD PREPARATION

pBR322

1. Palindromes with e.g. & diagram
2. Endonuclease vs. exonuclease
3. Restriction endonucleases, nomenclature
4. Cloning vectors, characteristics & diagram
5. Isolation of DNA, Enzymes
6. Gel Electrophoresis, Principle, Technique
7. Modes of Transformation (Ti, Competence, Microinjection, Gene Gun)
8. PCR
9. Types of Bioreactors, Downstream Processing
10. Selection (Antibiotic: Replica Plating; Insertional Inactivation)
11. Bt, cry
12. Insulin Production
13. RNA interference, ADA deficiency
14. Bioethics, Biopatents
15. GEAC

BOARD PREPARATION: Practise Question Paper

Single cell to life

Amazing video of formation of a new Organism from single cell

Click On Link below  👇👇

Cell to organism

Beautiful ❤️❣️❣️

Key Points: Evolution Part 3

	Supports to Natural Selection: Anthropogenic Selection Artificial Breeding Industrial Melanism Insecticide/Pesticide Resistance Resistance to antibiotics
	Adaptive Radiation: process of evolution of different species from a geographical area, by moving into different geographical area (habitat). E.g Australian Marsupial More than one adaptive radiation in an area – Convergent evolution e.g. Australian Marsupial & Placental mammals
	Vestigial organs: Organs present in non-functional forms. e.g. Vermiform appendix, Nictitating Membrane, hair on body
	Connecting Links: organisms possessing characters of two different groups of organisms, e.g. Connecting Links Organism Groups Euglena Plants & Animals Peripatus Annelida & Arthropoda Balanoglossus Non-chordates & Chordates Chimaera Cartilaginous & Bony Fish
	Missing Links: Fossil evidence showing combined forms of two groups. E.g Archaeopteryx (reptiles & Birds)
	Atavism: reappearance of ancestral characters. E.g. short tail in human babies, winged petiole in citrus
	Lamarck’s Theory: Use & Disuse of organs Characters are acquired due to new needs in changing environment.
	Mutation Theory: Hugo de Vries (Evening Primrose) New species originate due to mutations or discontinuous variations Mutations subjected to natural selection If unfavourable; destroyed
	Synthetic Theory: synthesis of Darwin’s & Hugo de Vries theories Five basic factors of evolution: 1.       Mutations 2.       Gene Recombinations 3.       Gene Migration / Gene Flow 4.       Genetic Drift              Founder Effect 5.       Hybridisation
	Types of Natural Selection: 1.       Stabilising Selection: favours average characteristics & eliminates extremes 2.       Directional/Progressive Selection: favors non-average or extreme for of trait & pushes population in one direction 3.       Disruptive Selection: favours both extremes and eliminates individuals with average traits. Forms two peaks in population. Two different populations formed. Disruptive section leading to formation of two new species – adaptive radiation
	Hardy Weinberg Principle: Describes theoretical situation where no evolution is occurring in a population i.e. frequency of alleles in a population is constant – genetic equilibrium uses algebraic equation: For a gene A with 2 alleles A & a Genotypes        Frequency AA                         p aa                          q Aa                         2pq Where, p frequency of dominant allele in population                q frequency of recessive allele in population              p2 Probability of occurrence of homozygous dominant              q2 Probability of occurrence of homozygous recessive             2pq Probability of occurrence of hetrozygous Allele frequency: p+q=1 So genotype Frequency: p2+q2=2pq=1
	Conditions/Absence of Genetic Equilibrium: Absence of Mutation, Gene Flow, Genetic Drift, genetic recombination, natural selection Founder Effect: Drifted population forming a new species (founder species) in the new area.
Lobefins (Coelacanth): fish capable of traversing between land & water Difference in eggs of amphibians & reptiles?	Evolution chronology: 3 eras: Paleozoic, Mesozoic & Cenozoic Age of Ferns & Amphibians: carboniferous Origin of Angiosperms & Age of Dinosaurs: Jurassic Current Age: Quaternary
	Evolution of Man: Dryopithecus: 15mya, knuckle walker Ramapithecus: 14-15 mya, walked like gorilla Australopithecus: 5mys, erect walker, omnivorous Cranial capacity 500cc Homo habilis: 2 mya, fully erect, vegetarian (no meat), tool maker Cranial capacity 650 – 800 cc Homo erectus: 1.5mya, meat eaters, used fire, Cranial capacity 900cc Neanderthals: 40,000 to 100,000 yrs ago, Omnivorous, Cranial capacity 1400cc Homo sapiens: 25,000 yrs ago, Omnivorous, Cranial capacity 1300-1600cc

Key Points Evolution: Darwin's Theory & Evidences (Part 2)

	Evolution of Life: Charles Darwin: ship – HMS Beagle Location: Galapagos;  Animal: Finches
	Theory of Natural Selection: Mechanism of Evolution 1.       Population if unchecked increases exponentially 2.       Resources are limited leading to struggle 3.       Population has built in variations in characteristics 4.       Characters which help an individual to survive better in natural conditions are favoured 5.       This leads to survival of the fittest. ‘Fit’ / ‘Fitness’ by Drawin refers only to Reproductive fitness
	Similar conclusions given by Wallace, work at Malay Archipelago.
	Evidences of Evolution: 1.       Fossils/Paleontological Evidence 2.       Comparative Anatomy & Morphology 3.       Embryology 4.       Molecular Evidences
	Fossil: hard parts of life forms found in rocks. Age estimated by C dating
	Comparative Anatomy: Similar structures developed along different lines due to different needs of the organism (adaptations) – Divergent Evolution. Structures k/a Homologous Homology indicates common ancestry e.g. forelimbs of mammals (bats, whales, humans – all have humerus, radius, ulna, carpals, metacarpals & phalanges) Vertebrate Heart/Brains Thorn & Tendril of Bougainvillea & Cucurbita
	Different Structures evolving for similar functions, hence appear similar – convergent evolution Structures k/a analogous e.g. eye of octopus & mammals flippers of Penguins & Dolphins sweet potato root & Potato Stem
	Embryological Evidences: Biogenetic Law: Ontogeny recapitulates Phylogeny Given by Haeckel Ontogeny – development of embryo Phylogeny: development of race / evolution Thus during embryo stages of all vertebrates, embryos of fish are seen In plants: Protonema of ferns & Moss similar to Algae Primitive Gymnosperms have flagellated sperms like Pteridophytes Leaves in seedlings of Acacia are similar, while in adults – compound
	Molecular  Evidences: Biochemical Similarity Similarity in amino acids, nucleic acids, Common Genetic Code Only 1.8% difference in DNA of Humans & Chimpanzee Amino acids sequence of Cytochrome C – identical in them.

Key Points: Evolution (Big Bang & Origin) Part 1

XII	EVOLUTION
QUESTIONS	NOTES
	Age of universe: 20 bn yrs ago Age of Earth: 4.5 bn yrs ago Life appeared: 4 bn yrs ago
	Universe m/o clusters of galaxy. Galaxy m/o clusters of stars, clouds of gases & dust. BIG BANG THEORY: explains origin of universe.
	Composition of Earth: Water vapour, methane, CO2, NH3 (frm molten mass on Earth’s surface) No atmosphere
	Processes on Earth post big bang led to formation of CO2, water etc.
	Theories of Origin of Life: ·       Panspermia: Life came from outer space as ‘spores’ ·       Spontaneous generation: Life originated from decaying matter ·       Life comes from pre-existing life – Louis Pasteur ·       Abiological Origin of life: Oparin & Haldane ·       Exp demo of above: Miller
Define Biogenesis	Biogenesis/ Chemical Evolution: Inorganic molecules            Non-living organic molecules s/a proteins, RNA etc.                                                   Life Conditions required: High temp, Volcanic storms, reducing atmosphere containing CH4, NH3 etc
	Miller’s exp: Flask with: CH4, NH3, H2 (red. Atm)                      Water vapour                      Electric Spark (high temp – 800°C) Result: Amino acids formed Further Proof: ·       Others obtained sugars, pigments, fats, N bases in similar exp ·       Meteorite content reveals similar material from other places in space

Key Points: Chapter 1 Reproduction In Organisms

XII	Chapter 1:  Reproduction In Organisms
QUESTIONS	NOTES
	Life Span: Period frm birth to natural death
Why unicellular org immortal?	Life span not related to size (e.g. mango – short; peepal – long)
	Reproduction significance: Continuity of species
Sexual vs asexual rep	Factors on which mode of reproduction depends: habitat, internal physiology etc.
Y asexual rep progeny k/a clones?	Cell div mode of rep in unicellular org.
	In favourable condition - Binary fission: In amoeba & paramecium (two equal halves) In Unfav conditions: Encystation & Sporulation (formation of minute Amoeba or Pseudopodiospores)
	Budding: yeast (2 unequal halves)
Asexual vs vegetative What are veg. Propagules?	In Fungi & Algae: Asexual rep through spores: Types: Zoospores – motile; zygospores – non motile Conidia – in Penicillium; Gemmules – in Sponges Fragmentation – Hydra
	Water Hyacinth (terror of Bengal), high rate of veg propagation.
	Veg propagules: Potato: Buds (eyes), Banana & Ginger: Rhizome;  Bryophyllum: Adventitious buds on leaf margins…… Key feature: NODE
	In simple org: asexual rep in fav conditions; sexual in unfav (provides variations, enables protection by hard seed coat) In higher org: sexual rep common, asex rare. In animals only sexual
	Sexual Rep: Elaborate, Complex & Slow. Offspring not identical to parents
Veg, rep & senescent phase in annual, biennial & Perennials	Common pattern of sexual rep: Complete juvenile/vegetative (in plants) phase Beginning of rep phase (flowering in plants) senescent phase Length of the 3 phases variable in different organisms Hormones responsible for transition between 3 phases. Unique: Bamboo perennial but flowering once in lifetime Strobilanthus kunthiana once in 12 yrs.
Seasonal Breeders vs Continuous breeders.	Animals: e.g. birds seasonal breeders in nature (in captivity; exploited) Placental Mammals: Cyclical changes in ovaries & Hormones Non primate mammals: Oestrous Cycle Primate mammals: Menstrual cycle
Events: Pre-fertilization, Fertilization & Post fertilization
	Gametogenesis: Male & Female, haploid, may be homogametes (isogametes) or heterogametes. Male: antherozoid or sperm; female: egg or ovum
	Sexuality in plants: Unisexual/Dioecious/Heterothallic e.g. papaya, date palm OR Bisexual/Monoecious/Homothallic Male: staminate; Female: Pistillate If make and female flower on different plants: dioecious If male & female flower on same plant: Monoecious
	Sexuality in animals: Bisexual (Hermaphrodite): Earthworm, Sponges, tapeworm & leech Unisexual: Rest
	Gamete Formation: Haploid

Why DNA is preferred Genetic Material

Genetic material should be capable of:

1. Stability: storing genetic information, chemical & Structural stability
2. Expression: able to express in from of traits or 'Mendelian Characters'
3. Replication: Be able to duplicate genetic material accurately
4. Inheritance: pass on copies of genetic information to next generation 
5. Evolution: allow production of variations through mutation or recombination

DNA vs RNA as genetic material

Both DNA and RNA have ability to act as genetic material but RNA preferred because:

1. DNA has Deoxyribose while RNA has Ribose - Chemical stability
2. Thymine in DNA while Uracil In RNA - Chemical stability

Chemically less reactive

➤Stability proved by Transformation (Griffith's experiment)

1. DNA double stranded, RNA single stranded - structural stability
   
2. Ability to replicate: complementary base pairing in dsDNA allows accurate copying during semiconservative replication 

Both DNA & RNA can express themselves through proteins. In fact protein synthesis cannot occur without RNA.

Ability to undergo mutation: both DNA & RNA able to mutate. In fact RNA mutates faster than DNA.

RNA being more reactive, and DNA being more stable; DNA was preferred over RNA as genetic material.

Now having read the topic try answering these questions:

1. Why is RNA more suitable in a catalytic role?
2. It is difficult to develop vaccines against RNA viruses s/a Rhinovirus (common cold Virus) or HIV?  
3. Justify, RNA is better suited for transmission of genetic information.