Saturday, February 29, 2020
EXAM POINTS FOR NEET BIOLOGY
2. T.O. Diener discovered a: Free infectious RNA
called viriodes
3. Mannitol is the stored food in Fucus
4. Equisetum is a vascular cryptogam
5. Phylogenetic system of classification is based on Evolutionary relationships
6. Aschelminthes
(round worms),annelid,arthropoda,mollusca and chordates are bilaterally symmetrical and
triploblastic.
7. Peripatus is a connecting link between Annelida and Arthropoda
8. ) Lampreys and hag
fishes comprises ‘jawless vertebrates.
9. If a live earthworm is prickled with a needle on its
outer surface without damaging its gut the fluid that comes out is coelomic fluid .
10. Plasmodesmata are connections
between adjacent cells
11. Stroma in the chloroplasts of higher plant contains light-independent reaction enzymes
12. Synapsis occurs between two homologous chromosomes during zygotene stage.
13. Middle lamella is composed mainly of Calcium pectate
14. Cytoskeleton is
made up of Proteinaceous filaments
15. The cell junctions called tight, adhering and gap
junctions are found in Epithelial tissue
16. The kind of tissue that forms the supportive structure
in our pinna (external ears) is also found in Tip of the nose is cartilage.
17. Ciliated epithelial
tissue present on the inner surface of bronchioles and fallopian tubes .
18. Genetic code is unambiguous,a codon in mRNA is read in a in contiguous
fashion. It is nearly universal. It is degenerate
19. Removal of introns and joining the exons in a define
order in a transcription unit is called Splicing
20.semiconservative replication of DNA was first demonstrate
in Escherichia coli by Messelson and Stahl and in
Vicia faba by Taylor.
21. Nirenberg and
Mathaei cracked the DNA and discovered unequivocally that a genetic code is
a “triplet.
22. Point mutation involves change in single base pair
23. In the case of peppered moth (Bistonbetularia) the
black-coloured form became dominant over the
light-colored form in England during industrial revolution. This is an
example of natural
selection whereby the darker forms were
selected.
24. Sickle cell anemia is
aused by a change in a single base pair of DNA.Gag coding or glutamicacid
changes to GUG coding or valine.
25. The most popularly known blood grouping is the ABO
grouping. It is named ABO and not ABC, because “O” in it refers to having no antigens A and B on RBCs.
26. Baldness is a
sex-influenced trait. Linkage is an exception to the principle of
independent assortment in heredity.Galactosemia
is an inborn error of metabolism.Small
population size results in random genetic drift in a population
27.Cotyledons and testa respectively are edible parts in ground nut and pomegranate
28. An example of a seed with endosperm, perisperm, and
caruncle is: Castor .
29. Guard cells help in transpiration. Guttation is when a plant
pushes water out through tips of the leaves of plants. These are
special pores called hydathodes.
30. Manganese is required in photolysis of water during photosynthesis
31. Oxygenic photosynthesis occurs in Oscillatoria.
32. Fruit developed
from hypanthodium inflorescence is called
Syconus
33. The annular and spirally thickened conducting elements
generally develop in the protoxylem when the root or stem is maturing.
34. Lemon is an
example of axile placentation .
35.In barley stem vascular bundles are closed and scattered.
36. Aerobic respiratory pathway is appropriately termed amphibolic
37. Palisade parenchyma is absent in leaves of sorghum .
38. Reduction in vascular tissue, mechanical tissue and
cuticle is characteristic of hydrophytes.
39. Anatomically fairly old dicotyledonous root is
distinguished from the dicotyledonous stem by
position of
protoxylem .
40. Cyclic photophosphorylation results in the formation of ATP.
41. In a standard ECG
the P-wave represents the electrical excitation (or depolarisation) of
the atria, which leads to the contraction of both the atria.
The QRS complex
represents the depolarisation of the ventricles, which initiates the
ventricular contraction.
The T-wave
represents the return of the ventricles from excited to normal state
(repolarisation) and the end of the T-wave marks the end of systole.
42. Uric acid is the chief nitrogenous component of the
excretory products ofinsects,rep[tiles and birds.
43. Fat and cellulose
in humans reaches the stomach totally undigested.
44. Iris –
Involuntary smooth muscle,Heart wall -
Involuntary cardiac muscle, Biceps of upper arm – Striatedmuscle fibres.
Abdominal wall – Striated muscle
45. Compared to blood our lymph has more WBCs and no RBCs
46. If the stretch
receptors of the urinary bladder wall are totally removed there
will be no micturition.
47. Hypothalamus
of human brain is concerned with the regulation of body temperature.
48. A young infant may be feeding entirely on mother’s milk
which is white in colour but the stools which the infant passes out is quite
yellowish. What is this yellow colour due to bile pigments passed through bile juice.
49. Globulins contained in human blood plasma are primarily
involved in defence mechanisms of body
50. Seminal plasma in humans is rich in Fructose, calcium and certain enzymes
51. Cytosine, uracil, thiamine – Pyrimidines. Malleus, incus,
stappes – Ear ossicles.Ilium, ischium,
pubis – Coxal bones of pelvic girdle.Actin, myosin, troponin and
tropomyosin. – Muscle proteins
52. About 30% of starch is hydrolyzed by salivary amylase in
our mouth. Oxyntic cells in our stomach secrete the Hcl.Fructose and amino acids are absorbed through intestinal mucosa with
the help of carrier ions like Na+.Chylomicrons are small lipoprotein
particles that are transported from intestine into lacteals.
53. Transpiration and root pressure cause water to rise in
plants by pulling and pushing it,
respectively
54. Elbow joint is an example of hinge joint,
55. Heterospory is
considered important in the development of seed habit.
56. NAA is a synthetic auxin .
57. Abscisic acid is
a derivative of carotenoids.
58. Vegetative propagation in mint occurs by sucker.
59.Pinus is monoecious.
60. Foetal ejection reflex in human female is induced by full developed foetus and placenta.
61. Menstruation :
Breakdown of endoometrium and ovum not fertilized.Ovulation : LH attain peak level .Proliferative phase :
Rapid regeneration of endoometrium and
maturation of Graafian follicle.Development
of corpus luteum-Secretory phase and increased
secretion of progesterone
62. Fertilization of
the ovum is the most likely root cause why menstruation is not taking place
in regularly cycling human female.
63. The correct sequence of spermatogenetic stages leading
to the formation of sperms in a mature human testis is: Spermatogonia – Spermatocyte –
Spermatid – Sperms
64.A change in the amount of yolk and its distribution in
the egg will affect the pattern of
cleavage.
65. When breast feeding is replaced by less nutritive food
low in proteins and calories; the infants below the age of one year are likely
to suffer from: Marasmus
66. Fishes occupy more than one trophic level in a pond
ecosystem.
68.Montreal protocol aims at reduction of ozone depleting substances
69. Chipko movement was launched for the protection of
forests. The Chipko movement, or Chipko Andolan,
was a forest conservation movement in India. It began in 1970s in
Uttarakhand, then a part of Uttar Pradesh(at the foothills of Himalayas) and
went on to become a rallying point for many future environmental movements
all over the world.
70. The correct sequence of plants in a hydrosere is Volvox → Hydrila → Pistia → Scirpus→ Lantana
→ Oak
71. Steps taken by Government of India to control air
pollution include:Use of non-polluting
Compressed Natural gas (CNG) only has fuel by all buses and trucks
72. Biochemical Oxygen Demand (BOD) in a river water increases when sewage gets mixed with river
water.
73. DDT residues are rapidly passed through food chain
causing bio magnification because DDT is liposoluble.
74. Global agreement in specific control strategies to
reduce the release of ozone depleting substances, was adopted by the Montreal protocol.
75. Somaclones are obtained by tissue culture
76. Root knot of vegetables – Meloidogynesp. Late blight of potato – Phytophthora infestans. Black rust to wheat –
pucciniagraminis .Loose smut of wheat - Ustilagonuda
77. Bacillus thuringiensis,Trichoderma harzianum and Nuclear
polyhedrosis virus (NPV) are used as biopepesticide.
78. Zea mays
species select for the production of bioethanol.Jatropha for biodiesel.
79. Frankia and rhizobium are symbiotic nitrogen fixes.
80. A health disorder that results from
the deficiency of thyroxine in adults and characterized by (i) a low metabolic
rate, (ii) increase in body weight and (iii) tendency to retain water in tissue
is Myxoedema
81. Malignant tumours
may exhibit metastasis.Benign tumours does not show the the property of metastasis
82. smallpox.the common cold , measles, mumps, rubella, chicken pox, shingles, hepatitis,herpes and cold sores,
polio, rabies ,Ebola and AIDS are viral diseases.
. 83. A person likely
to develop tetanus is immunized by administering Preformed antibodies
84. Use of anti-histamines and steroids give a quick relief
from allergy.
85. Alzhimer disease in humans is associated with the
deficiency of: Acetylchlorine
86. Agrobacterium
tumefaciens is commonly used in transfer of foreign DNA into crop
plants.
87. The bacterium Bacillus thuringiensis is widely used in
contemporary biology as insecticide.
88. Textile – amylase- Detergents – lipase-Fruit juice –
pectinase
89. Polyethylene glycol method is used for Gene transfer without a vector
90. Transgenic plants are the ones generated by introducing foreign DNA in to a cell and regenerating a
plant from that cell.
91. Bt toxin is a
inactive protoxin gets converted into active form in the insect gut.
92. The genetic defect- adenosine deaminase (ADA) deficiency
may be cured permanently by) Introducing
bone marrow cells producing ADA into cells at early embryonic stages .
93. There is no DNA in Mature
RBCs.
94. The letter T in T-lymphocyte refers to thymus.
95. Lion a resident
in Gir national park?
96. The eye of octopus and eye of cat show different
patterns of structure, yet they perform similar function. This is an example of
Analogous organs that have evolved due
to convergent evolution
97. Accumulation of
uric acid crystals in joints causes their inflammation called gout.
98. A phosphoglyceride is always made up of A saturated or unsaturated fatty acid
esterified to a glycerol molecule to which a phosphate group is also attached.
99. Perisperm differs from endosperm in being a diploid tissue
100. A sedentary sea anemone gets attached to the shell
lining of hermit crab. The association is:
commensalism
Lecture notes on DNA -Microarrays
Microarrays are linear arrays of molecules immobilized at definite locations on an inert solid support such as a glass slide allowing them to be studied simultaneously.
DNA microarrays and protein microarrays are widely being used in genomics and proteomics, respectively.
Principle:
Microarray technology is based on the principle of hybridisation between a 'probe' and target molecules that are to be detected.
This is based on complementarity between the two molecules -such as the base pairing of complementary strands of DNA or protein-antibody interaction.
The probes are attached to a solid support and the experimental sample is in solution.
Once the target molecules bind the probes, these are detected by appropriate methods.
DNA Microarray
An array is an orderly arrangement of samples.
It provides a medium for matching known and unknown DNA samples based on base-pairing.
An array experiment can be conducted on substrates such as microplates or standard blotting membranes.
To create an array, the sample may be deposited by hand or by robotics.
In general, arrays are described as macroarrays or microarrays, the difference being the size of the sample spots. Macroarrays contain sample spot sizes of about 300 microns or larger and can be easily imaged by existing gel and blot scanners.
The sample spot sizes in microarray are
typically less than 200 microns in diameter and these arrays usually contain thousands of spots.
DNA microarrays or DNA chips, which have DNA molecules (the probes)
immobilized at precise locations on a substrate have become well accepted platforms for studying gene expression and tracking mutations.
The solid substrate can be a silicon
wafer, a thin sheet of glass, plastic or a nylon membrane .
Microarrays are prepared by arraying the samples in the cells of the substrate by high-speed robotics.
In each reaction cell, trillions of polymeric molecules from a specific sequence of single strand DNA fragment are immobilized .
These known sequences of single
strand DNA fragments immobilized on the substrates are often called probes. Unknown fragments of single stranded DNA samples, called the target, are allowed to react or hybridize with the probes on the chip.
The double stranded DNA hybrids are formed in the chips where the target and the probe are complementary according to the base-pairing rule.
To facilitate the diagnosis or analysis of the hybridized chip, the target samples are
often labelled with tags, such as fluorescent dyes (say, red and green), or radioisotope molecules.
Spots with fluorescence can be detected using scanners interfaced with a
computer that generates an image of the array.
The image is then processed using
appropriate software packages to generate microarray data.
Applications
DNA microarrays can be used to detect DNA sequences in samples.
Microarray
technique can be used to detect cellular RNA indirectly (after reverse transcription
to DNA).
This method of measuring gene expression via CDNA is called expression
analysis.
Microarray technology has important applications in pharmacogenomics.
These include drug discovery and development, drug safety and molecular diagnostics.
DNA chips would also help evolve personalized medicines.
Thursday, February 27, 2020
Lecture notes on Micrometry
Micrometry involves measurement of minute or microscopic objects using microscope.The micrometer consists of two components namely a stage micrometer and an ocular micrometer
Stage Micrometer
This is a glass slide that can be mounted on the stage of the microscope. It
is similar to a microscope slide and measures 7.5 cm x 2.5 cm. It has a linear scale of length 1 mm engraved on it. This 1 mm distance is precisely divided into 100 equal divisions. Therefore each small division is equal to 0.01 mm (10 um). Every 5th and 10th divisions are demarkated by longer lines.
Ocular Micrometer
Ocular micrometer is a glass disc with a diameter of 21 mm. While in use, it
is placed on top of the field diaphragm of the eye piece. At the centre of this disc
is engraved an arbitrary linear scale with 100 equal divisions. Every 10th division
is demarkated by longer lines.
Calibration
The magnification of a microscope is calibrated using the stage micrometer
and ocular micrometer. This is done by determining the value of each arbitrary
division of the ocular micrometer in terms of millimeters or microns.For calibration, stage micrometer is mounted on the stage of the microscope and focussed until the graduations become visible. Then, the ocular micrometer is introduced on top of the field diaphragm of the eye piece. Once
the stage and ocular micrometer scales become visible, both are aligned parallel
to each other. The stage micrometer is then moved and positioned so that its
initial division (or any other division near to the initial division) coincides with
the initial division (or any other division near to the initial division) of the ocular
micrometer. The number of divisions on both the scales is counted upto a farthest
point where the two scale divisions again coincide. The value of one ocular
micrometer is calculated as follows:
Value of one ocular micrometer division=
Number of divisions on the stage micrometer /Number of divisions on the ocular micrometer X 100
The calibration is done both under the low power and high power of the microscope separately. When calibration is over, the stage micrometer is replaced with the slide containing the object to be measured. Upon focussing, the object
can be seen superimposed on the ocular micrometer scale. The dimensions of
the object are recorded in terms of the ocular micrometer divisions. Since the
value of each division on the ocular micrometer is known, the actual dimensions of the object can be derived easily.
Lecture notes on Camera Lucida and its importance.
A camera lucida is an optical device used for drawing the diagram of microscopic objects . It was invented in 1806 by William Hyde Wollaston and Christian Gobrecht
The term"camera lucida" means "lit room" in Latin. The camera lucida performs an optical
superimposition of the subject being viewed and the surface on which the
observer is drawing . The person sees both the image of the specimen
and drawing surface simultaneously, as in a photographic double exposure, This
allows the person to trace the outlines of the image using a pencil. If white paper
is used, the superimposition of the paper with the scene tends to wash out the
scene, making it difficult to view. Camera lucida works on simple optical principle reflecting beam of light through a prism and a plane mirror.
The microscopic image of the object is reflected by the prism on to the plane mirror and there from the image is reflected on to the plane white paper. The person who observe moves the pencil on the lines of the image and draws a correct and faithful figure of the object on the paper.
When working with a camera lucida it is beneficial to use black paper and to draw with a white pencil.Camera lucida sketches are often used to supplement photomicrographs to make clear illustration of a structure. In many cases, drawings on camera lucida may provide more clarity and comprehension than photomicrographs. Thus,histological and microanatomical illustrations in textbooks and research papers are often camera lucida drawings rather than photomicrographs.
Tuesday, February 25, 2020
Lecture notes on microevolution and macrevolution
Microevolution:The evolution which occurs on a small scale and within a single population is micro evolution.Changes in the gene pool, which results in a few changes in the same species also called Intra-species genetic change. The changes in micro evolution occur over short timescales.Genetic information gets altered or rearranged.As this process has been experimentally proven and so creationists support this type of evolution.
Example
The peppered moth, new strains of flu viruses, Galapagos finch beaks,Pesticide resistance, herbicide resistance, and antibiotic resistance are all examples of microevolution by natural selection
Macroevolution:The evolution that occurs on a large and surpasses the level of the single species is macro evolution.The macroevolution results in the formation of new species. The changes observed in macro evolution occurs over long-time scales.There is the new addition, deletion in the genetic structure, resulting in the new species.As there are many barriers in providing experimental proof and so creationists do not support this kind of evolution.
Examples:Origin of different phyla, development of vertebrates from invertebrates, development of featherrs and scales, evolution of birds fom reptiles
Lecture notes on Human Evolution-Different stages
Human evolution
Human evolution is the time taken process of change by which humans originated from apelike ancestors. Scientific proof suggested that the physical and behavioral traits shared by all human originated from apelike ancestors and evolved over a period of approximately six million years.
Taxonomic Position of modern man in animal kingdom
Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Mammalia
Order: Primates
Family: Hominidae
Genus: Homo
Species: Sapiens
Characters:
Highly developed brain and high cranial capacity.
Humans are more intelligent than others
The power of thinking and sense of self consciousness .
Humans posses erect posture and bipedal locomotion.
They have grasping hand.
Shifting from hunting life to cultivating life with culture and civilization.
It may statef that the origin and evolution ofman have occurred from the ape-like ancestor.The various stages are described as below
1.Parapithecus(Anthropoid):They were the common ancestor of human apes and monkey. Their fossils were discovered from Egypt. They have evolved 36 million years ago.
2.Dryopithecus:They were the common hominid ancestor of human and apes. Their Fossil was discovered from Europe and Africa. They have evolved 24 million years ago. They possessed a round forehead and pointed canine teeth.
3.Ramapithecus or shivapithecus:Fossil discovered from Shivalik hills of India and also from the Butwal and Dang of Nepal. They were the oldest and direct ancestors of humans.They were evolved 14 million years ago. They were arboreal in habit but also walked on the ground. They posses smaller canine and larger molar teeth.
4.Australopithecus: They were the first Human-like form of ape. It is regarded as the connecting link between human and apes. They evolved five million years ago Their fossils discovered from Africa. They were the first human ancestor showed bipedal locomotion. Their cranial capacity was 500 cc.
5. Homo habilis or Handyman or Skilful man:They were the first toolmakers(nutcrackers). They made various tools from stone. Their fossil discovered from East Africa. They were evolved 2 million years ago. Their cranial capacity was 700Cc. They had prognathous jaw, protecting brow ridge and narrow slopy forehead.
6.Homoerectus or Erect man:They have more erect posture. They made more elaborate tools from stone and bond. They have evolved 1.7 million years ago. They also had prognathous jaw, protecting brow ridge and narrow slopy forehead. They have three subspecies:
a.H.erectus erectus or Java ape-man: Their fossil was discovered from Java of Indonesia. They first used fire for cooking and protection. Their cranial capacity was 900 cc.
b.H.erectus pekinensis or Peking man: Their fossils were discovered from peking of China. They were shorter and lighter than Java ape-man. Their cranial capacity was 900- 1200cc.
c.H.erectus Heidelbergenosis or Heidelberg man: Their fossils were discovered from Heidelberg of Germany. They were much taller and heavier. Their cranial capacity was 1300 cc.
7.Homo sapiens neanderthalensis or Neanderthal man:Their fossils discover from Neander valley of Germany. They had slightly prognathous jaw with a broad nose. Their cranial capacity was 1300-1600 cc (equal to that of modern man).They were stronger than modern man. They developed society, culture, and division of labour. They lived in a cave. They buried dead bodies with the ceremony. They were omnivorous and cannibals. They were the skilled hunter. They used an animal skin for clothing. They became extinct 3000 years ago.
8.Homo sapiens fossilis or Cro-magnon man: They were the immediate ancestor of modern man. Their fossils were discovered from the cromagnon rock of France. They had the orthognathous jaw with a rounded forehead. Their cranial capacity was 1650 cc so supposed to be more intelligent than modern man. They made sculpture and color painting in the cave. They were omnivorous. They made more excellent tools like spears, bows, and arrows.
9.Homo sapiens sapiens(Modern man): They evolved 20,000 years ago and spread around Caspian and Mediterranean sea before 1000 years ago.Cranial capacity is 1450 cc They migrated towards different countries and develop into different races:
a. Caucasians: Those who migrate westward like Europe, Southeast Asia.
b. Mongoloid: Those who migrate eastward like ChinaJapan, Siberia etc.
c. Negroid: Those who move southward like Africa.
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