REPRODUCTION IN ORGANISMS PART II

In continuation with our previous discussion about introduction of first chapter, I'm uploading the second part.
In this part we'll be discussing Asexual reproduction: Modes & Significance.
Go through the video and try solving the assignments in between as well as at the end.

Practice Paper: class XII

Lesson Covered:

Strategies for Improvement in Food Production
Microbes in Human Welfare
Biotechnology: Principles & Applications

Time: 1 ½ hour                                                                                                                       MM 40

Instructions:

Q 1-5 (1 mark), 6-10 (2 marks), 11-15 (3 marks), 16-17(5 marks)

1.       Name the first transgenic cow developed and state the improvement in the quality of the product produced by it.

2.       Name the vector used for transferring nematode specific gene in tobacco plant.

3.       What is SCP? Name the organism used for production of SCP.

4.       A resistant variety of Abelmoschus esculentus show resistance against a virus. Name the virus and plant variety.

5.       “A person is suffering with high blood cholesterol.” Which kind of bioactive molecule you will suggest to reduce his cholesterol level?

6.       A banana herb is virus infected. Name the method that will help in obtaining healthy banana plants from this diseases plant.

7.       Name the insect pest killed by the product of cryIAb gene. Explain how this gene makes the plant resistant to the insect pest.

8.       What is activated sludge? Where is it produced? Why is it named so?

9.       What is inbreeding depression. How can it be overcome?

10.   How are sugarcane varieties with high yield, thick stem, high sugar formed that can be grown in North India?

11.   Explain the term MOET. Which hormone is used for this method. Give the key steps of MOET.

12.   What are palindromes? Where are they used?

13.   What was Cohen & Boyer’s contribution to field of Biotechnology? Show diagrammatically.

14.   What is PCR? Where is it used. Represent the key steps diagrammatically.

15.   Draw a well labelled diagram of a cloning vector showing:

Ori, rop, atleast two restriction sites & 2 antibiotic markers. Give function of each.

16.   (a)Write any one drawback of selection of recombinant due to inactivation of antibiotic. Explain how recombinants and non-recombinants are differentiated on the basis of colour production in the presence of a chromogenic substrate?

     (b)Explain why DNA is not able to pass through cell membrane? Which methods are available to make the plant cell competent to take up DNA from surrounding medium?

17.   Given below is the   sketch of one method used to separate DNA fragments:

                

(a) Give the term caption for above diagram.

(b) At which end would be loaded the samples and why?

(c) Analyse the reason for different positions taken up by the DNA bands.

(d)Elaborate the step he would have followed to visualize DNA bands.

(e) Name the gel used in this technique.

PRETEST: Principles of Inheritance & vaiation (Part 1)

Hello!

Starting with Unit 2.

Here are the pretest questions based on first 8 pages of Chapter 5. In my book (i.e. 2019-20 publication available online) the page numbers are 67-75. In terms of Topic; End of 5.2 (Inheritance of One Gene)

Read the pages carefully; and try to answer the questions. see how many you can answer.

The key points of this portion are already on blog, but I would request you not to refer them, and focus solely on book reading.

1.       Branch of Biology that deals with inheritance & variations _________

2.       ___________ is the basis of heredity.

3.       The major cause of variation is ______________; which has been used by humans for selective breeding.

4.       Experiments conducted by Mendel involved ___________ of true breeding Pea plants, which involved the technique of ___________.

5.       What was the advantage of taking large sampling size in Mendel’s experiment?

6.       Define true breeding lines.

7.       F₁ & F₂ in crossing stands for ___________ & _________.

8.       The ratios obtained by Mendel in F₁ & F₂ of monohybrid cross respectively was _________ & ____________.

9.       Factors of Mendel are equivalent to _______, and are units of inheritance required for expression of particular trait.

10.   T & t represent two forms of a __________, known as __________ which control expression of a trait.

11.   TT & Tt produce the same phenotype.

                                             i.            Capital T represents ________, small t represents _______.

                                           ii.            What conclusion was drawn by Mendel on the basis of this?

12.   The type of cell division that occurs during gamete formation is _____. Here only one _______ of a pair is passed in to a gamete.

13.   Graphical representation to calculate the probability of occurrence of different types of Genotypes in a cross is known as ___________.

14.   Self Pollination of a dwarf plant will give tall and dwarf in the ratio _:_.

15.   An organism exhibiting a recessive phenotype for tallness will have the following genotypes _________.; while an organism exhibiting a dominant phenotype for tallness will have the following genotypes _______________.

16.   Test cross is crossing tall (dominant phenotype) plant with ________ plant.

17.   Mendel gave ___ (no.) laws on the basis of monohybrid crosses; they are ___________ & _____________.

18.   _______ flower position & _______ flower colour in pea is dominant.

19.   The two seed related characters chosen by Mendel were ______ & _________.

The total number of true breeding

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

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 (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.