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Explanation: Air passes through nostrils, nasal cavities where some of the tiny dirt particles from the air are removed and the temperature of air is brought close to that of the body. Epiglottis, a flap like structure controls the movement of food and air towards respective passage. When air passes out of the lungs and over the vocal cords it causes to vibrate vocal cords and this produces sound. Wind pipe channeling air to lungs at lower end, the trachea divides into two bronchi on leading to each lung. Each bronchi is further divided into smaller and smallest branches called branchioles. These finally terminate in cluster of air sacs called alveoli in the lungs. Gaseous exchange takes place here as blood capillaries take up oxygen and expel carbondioxide.

Unique features of acquired immunity are as follows: 

a. Specificity:

Acquired immunity is specific for each type of pathogen. It has the ability to differentiate between various foreign molecules. 

b. Diversity: 

It has the ability to recognize vast variety of diverse pathogens or foreign molecules. 

c. Discrimination between self and non-self: 

It is able to differentiate between own cells (self) and foreign cells or molecules (non-self). 

d. Memory: 

When the immune system encounters a specific pathogen for the first time, it generates immune response and eliminates the invader. The immune system retains the memory of this encounter. As a result, a second encounter with same pathogen stimulates a stronger immune response.

The orderly increase in the quantity of all the cellular components is known as Growth.

Protoplasm is composed of a mixture of small molecules such as ions, amino acids, monosaccharides and water, and macromolecules such as nucleic acids, proteins, lipids and polysaccharides. In eukaryotes the protoplasm surrounding the cell nucleus is known as the cytoplasm and that inside the nucleus as the nucleoplasm.

Correct Answer is: (a) Refractive index of a glass slab

When the slab is placed on a flat surface, the real depth and apparent depths can be measured directly by the travelling microscope.

(i) Glomerular filtration : Blood flows inside the glomerulus under the influence of pressure due to the narrowness of efferent arteriole. As a result it undergoes pressure filtration or ultra filtration. Waste molecules, nutrient molecules and water are filtered out and enter the Bowman's capsule. 

(ii) Tubular reabsorption : The peritubular capillaries around PCT reabsorb all the useful components of primary urine such as glucose, amino acids, vitamin C, Potassium, Calcium, Sodium, Chlorides and 75% of Water. 

(iii) Tubular secretion : It is the active secretion of waste products by blood capillaries into the urinary tubule. It ensures removal of all the waste products from blood, viz., urea, uric acid, reatinine, salt ions like K⁺, Na⁺ and H⁺ ions. This maintains proper concentration and pH of urine.

Correct Answer is: (b)

Sharp images are obtained for small angles of incidence. For large angles of incidence, the images become indistinct and proper ray tracing becomes difficult.

(1) In photosynthesis solar energy is converted to chemical energy and is stored in plants as starch. 

(2) During photosynthesis plants absorb carbondioxide from the atmosphere. So it reduces the CO₂ level on the Earth. 

(3) In this process plants release oxygen as a by product. Oxygen is essential for all living things on the Earth. 

(4) Each year photosynthesis synthesizes approximately 160 billion metric tonnes of carbohydrates.

(a) 1.During photosynthesis, plants trap solar energy and by utilising simple inorganic substances like CO₂ and H₂O, they prepare complex organic substances like carbohydrates. 

2. These carbohydrates are utilised for providing energy for most living organisms including human beings. 

3. It is the only process which adds O₂ to the atmosphere and makes our living possible. 

(b) 1. Dark reaction of photosynthesis does not require light energy. 

2. The term dark reaction does not mean that they occur when it is dark or at night. 

3. It only means that the reactions are not dependent on light as in light reaction. 

(c) 1. To get better results from related experiment, it is necessary to destarch a plant before performing any experiment on photosynthesis. 

2. The plant which is kept in the dark place for few days for the removal of starch from the leaves, is called a destarched plant. 

3. It is to precisely to estimate the amount of starch produced after experiment. 

(d) 1. During day time, plants carryout photosynthesis actively. 

2. During this time O₂ given out as a by-product is taken up by plants for respiration. 

3. Not only this, CO₂ produced during respiration will be used in photosynthesis. 

4. Thus, both photosynthesis and respiration are inter related, it is not possible to demonstrate respiration during day time.

Photosynthesis is the process in which green plants use sunlight to make their own food. Photosynthesis requires sunlight, chlorophyll, water, and carbon dioxide gas as raw materials. Chlorophyll is a substance in all green plants, especially in the leaves. Plants take in water from the soil and carbon dioxide from the air.

Photosynthesis Site:

• Photosynthesis occurs in chloroplasts, which are unique organelles. Because this organelle has its own DNA and genes, it can produce its own proteins.
• The stroma, fluid, and grana comprise chloroplasts. Chlorophyll a, chlorophyll b, and carotenoids are three essential pigments that absorb light energy in the chloroplast.

Types of photosynthesis:

There are two types of photosynthetic processes: oxygenic photosynthesis and anoxygenic photosynthesis. The general principles of anoxygenic and oxygenic photosynthesis are very similar, but oxygenic photosynthesis is the most common and is seen in plants, algae and cyanobacteria. 

An ecosystem with high species diversity is much more stable than an ecosystem with low species diversity. Also, high biodiversity makes the ecosystem more stable in productivity and more resistant towards disturbances such as alien species invasions and floods.
If an ecosystem is rich in biodiversity, then the ecological balance would not get affected. As we all know, various trophic levels are connected through food chains. If any one organism or all organisms of any one trophic level is killed, then it will disrupt the entire food chain. For example, in a food chain, if all plants are killed, then all deer’s will die due to the lack of food. If alldeer’s are dead, soon the tigers will also die. Therefore, it can be concluded that if an ecosystem is rich in species, then there will be other food alternatives at each trophic level which would not allow any organism to die due to the absence of their food resource.
Hence, biodiversity plays an important role in maintaining the health and ecological balance of an ecosystem.

Example of corm is  Colocasia (ol) 

Steam is widely used in heat sterilization, where an autoclave is filled with steam heated to 121–134 °C (250–273 °F).

Methanogens do not produce is Oxygen.

Sterilization is a surgical process whose entervention blocks gamete transport and thereby prevent conception. Sterilization procedure in the male is called ‘vasectomy’ and that in the female ‘tubectomy’. 

(d) All of them

S.L. Miller in his experiment in 1953 used methane, hydrogen, ammonia at 800°C. At the end of experiment he obtained amino acids.

The adaption in wind pollineted flowers are given below:

(i) The size of flower is very small

(ii) Bright coloured corolla. nectar glands and fragrance are absent

(iii) Flower are grouped together in clusters

(iv) pollen grains are produced in large quantities

(v) Versatile Fixation of anthers aid in shaking off pollen grains in the air

(vi) pollen grains are dry smooth and very light. e.g. coconut Palm date palm

DNA replication is  Semi-conservative, semi-discontinuous.

Alcohol disuse showed following long term disadvantages in men 

(i) Harmful effect on nervous system. 

(ii) Damage of liver (serosis). 

(iii) During pregnancy its use caused adverse effects on embryo. 

In plants, Meiosis occurs in  Anther.

Vaccination, pathogens, antigens proteins are directly injected into the body in its very small quantity and body show primary immune response and protect the body from harmful infection. 

The properties of genetic code are as follows:– 

(a) Triplet nature – The genetic code is a triplet code which is arranged in a sequence on m-RNA. 

(b) Unambiguous and specific – One codon codes for only one amino acid, hence it is unambiguous and specific. 

(c) Degenerate code – Some aminoacids are coded by more than one codon, hence the code is degenerate. 

(d) Commaless form – There are no comma and punctutation marks between the coding triplets (Codons). 

(e) Universal – The code is nearly universal. For example, from bacteria to human UUU would code for Phenylalanine (Phe). 

(f) Nonsense or Terminator Codon – Three of the 64 codons, namely UAA, UAG and UGA, do not specify any amino acids, but signal the end of the message. 

(g) Initiation codon – AUG and sometime GUG are the initiator codon. As AUG stands for methionine, polypeptide chain begins with methionine when they are synthesized. 

Bacteria are a cellular (unicellular) small creatures which can be seen only through a microscope. They are found in air, seas, lakes and in the intestine of men and other creatures. They are in the shape of Coccus, Bacillus and Spirillium. They multiply quite rapidly through simple fission (division of cell) or sexual or asexual reproduction. Lakhs of bacteria are produced within an hour.

Advantages of Bacteria:

(i) Some bacteria are useful in agriculture. It increases soil fertility. These bacteria are capable of converting atmospheric free nitrogen into nitrogenous compounds which is essential for all plants. Some Bacteria attack dead bodies of plants and animals and convert their complex compound into simpler substances, e.g. carbondioxide (CO₂), Water(H₂O), Nitrates(NO₃), Sulphate(SO₄) etc.

(ii) Bacterium lactici acidi and B. acidi lactici are found in milk. These bacteria ferment lactose sugar found in milk to form lactic acid by which milk becomes sour. Lactic acid bacteria help in the formation of curd.

(iii) Some bacteria are very much useful in industries. Vinegar is manufactured from sugar solution in the presence of Acetobacter aceti. Clostridium acetobutylicum takes part in the manufacture of butyl alcohol and acetone. Bacteria helps in fibre ratting. The process of fibre ratting is carried out by clostridium butyricum inhabiting in the water. In tobacoo industries Bacillus megathenium mycococcus is used for its fermentative capacity for developing flavour and taste in tobacco leaves. In tea industries by fermentative action of Mycocccus candisdans, special taste is developed in the tea leaves. Some bacteria are useful in tanning of leather. They decompose fats which are found in skin of animals with the result that skin and hairs are separated from each other and this leather ready for use.

(iv) Some bacteria are useful in manufacturing medicine. Some of the antibiotics are manufactured by bacterial actions. a.g. Bacillus brevis-antibotic thyrothricin, B subtilis-abtibiotic subtelin. Vitamin B₂ is manufactured by ferentative action of clostridium acetobutylicum. Some of the antibiotic are obtained from different species of streptomyces. Such as streptomycin (from Bacteria streptomyces grisieus), chloromycetin (from S. Venezuelae), Auremycin (from aureofaciens), Terramycin (from rimosu) Neomycin (from fradiae). etc.

Anemophily is a mode of pollination or transfer of pollengrains from anther to stigma through the agency of wind. The flowers which are wind pollinated are called anemophilous. The anemophilous flowers are characterized by the following adaptation:– 

(a) Flowers are small, colourless, inconspicuous, odourless and nectarless. 

(b) Calyx and corolla are either reduced or absent. 

(c) Filament of stamens are usually long and versatile. 

(d) Pollengrains are small, light, dry, dusty and sometimes winged (e.g. pine). 

(e) Pollengrains are infinite in number. 

(f) Stigmas are hairy, feathery and branched. 

(g) When flowers are unisexual, male flowers are more abundant than female flowers. In bisexual flowers, the stamens are generally numerous. 

Example of wind pollinated flowers are grasses, sugarcane, bamboo, maize etc.

Microbes are essential for human welfare because they help through various ways in promotion of our health, foods, agro product and reduction of pollution level as well.

These are illustrated below:– 

(a) Microbes are essential for production of diary products like paneer, curd, butter etc. which are processing products of milk. Their production is carried out by the microbes such as bacteria. Similarly bread, idli, vinegar are produced by the activity of microbes. 

(b) By using Mithanogen bacteria, production of biogas is possible. 

(c) Microbes also help us in a treatment of domestic waste water. 

(d) In the field of industries, by activity of microbes we obtain alcoholic drinks of ionous type, organic acids, vitamin B₂ and B₁₂, dextrins, steroid, aminoacids, cyclosporin etc. which all enhances our life.

(e) Microbes are used in the field of treatment against infectious diseases. 

(f) In the field of agriculture, microbes are used to increase production of agriculture. We used microbes as pesticides, weedicides which improve our environmental health. 

(g) Microbes are also used as ‘single cell protein’ which fulfills our protein requirements.

The maintenance of hives of honey bees for the production of honey is called bee keeping or apiculture. 

Bee keeping is a small scale industry for the production of honey which have following economic importance:– 

(i) Bee keeping gives honey which is an important nutritive substance. 

(ii) Bee-hives gives bee-wax which is utilized in making polishes. 

(iii) Bee keeping helps in pollination of various crops useful for mankind.

The biological wealth of our planet has been declining rapidly which leads to loss of biodiversity. The loss of biodiversity in a region may lead to many effects, such as–

(a) Decline in plant production, 

(b) Lowered resistance to environmental perturbations, and 

(c) Increased variability in certain ecosystem processes. 

Causes of biodiversity losses are:– 

(1) Habitat distruction and fragmentation – Due to intense antitropogenic activities the number of temperate rain forests are greatly minimized. As a result enumerable species living or in are being extinct. Due to increased pollution load, the biotic habitat is being fragmented as a result many species are extinct. 

(2) Over exploitation – Human beings has over exploited the natural resources for their need and greed, as a result many species of commercial importance are either become extinct or are on the verge of extinction. 

(3) Invasion of exotic species – The inclusion of exotic species in any ecosystem either knowingly or unknowingly has greatly affected the existence of local species. The invasion of exotic species is one of the principal cause of their distruction. 

(4) Co-extinction – when one species becomes extinct the species of plants and animals associated with it also become extinct. Like the extinction of a plant having mutual relationship with an insect, leads to extinction of the insect also.

 4 peptide chains are found in each antibody molecule.

Crossing over is the exchange of genetic material between homologous chromosomes that results in recombinant chromosomes during sexual reproduction. 

Its uses are as follows : 

(i) For producing new combination of genes.

(ii) For development of new species. 

(iii) Mapping of chromosome is prepared by frequency of crossing over.

Uses of DNA finger printing : 

(i) Paternity test. 

(ii) Identification of criminal. 

(iii) Mapping of Human genome.

When DNA cut into fragments with restriction enzymes into precies reproduclble sequences is known as restriction endonuclease.

DNA fingerprinting is a teachnique to find out variations in individuals of a population at DNA level.

Applications of DNA fingerprinting are given below:-

(i) Paternity disputes can be solved by DNA finger printing

(ii) It can solve to study the breeding patterns of animals facing the danger of extinction

(iii) It can be used to study the bre is useful in rest oring health of the patients suffring from the leukenia (blood cancer)

(iv) It is very sue ful in the detection of crime and legal pursuite

Immigration- It is the number of individuals of the same species that have come into the habitat from elsewhere during the considerable time period. 

Emigration- It is the number of individuals of the population who left the habitat and gone elsewhere during the considerable time period.

Answer (c) Diphtheria

Following are five bacterial diseases in human :– 

(a) Tuberculosis – Mycobacterium tuberculosis 

(b) Whooping cough – Bordela pertussis 

(c) Cholera – Vibro cholera 

(d) Typhoid – Salmonella typhi 

(e) Leprosy – Mycobacterium leparae

Following five viral diseases and its causative agent:– 

(a) Small pox – Variola virus 

(b) Rabies (Hydrophobia) – Lisa virus type I 

(c) Hepatitis – Hepatitis A virus 

(d) Polyomelites – Polio virus 

(e) AIDs – HIV virus

Biotechnological applications in medicine and human health-

(i) Genetically engineered insulin 

(ii) Interferon

(iii) Human growth hormone 

(iv) Vaccine preparation

(v) Monoclonal antibodies 

(vi) Antibiotics

(vii) Gene therapy

In laborating favarasle asepticand presence of important meneralselt growth hormon etc. when we develope zygot, tissue or expalnt is known as tissue culture. In another words we say that for hybridization experimental work when we formed laploid plants are known as tissue centre.

Answer (d) Organic farming

Two applications of biotechnology in the field of medicine are given below:-

(i) By syncona wegotquinian. It is a usefull medicine in maliria disease

(ii) Practiamole, Pencilire etc. are use in higher antibiotic in different type of dissase.

Answer (c) Stephan Hales

Menstrual cycle:-

It is involves cyclic changes in the femal' reproductive tractculminating in mens truation, that is flow of cast off uterine and fallopian tube lining along with blood and tissue fuid through in vagina. It consists of three phases- Proliferative lohase, secretary phase and menstrual phase.

The various phases with harmonal regulation in menstrual cycle is given below:-

(i) Follicular Phase:- It begins on the fifth day of cycle. It lasts up to fourteenth day. The endo metrium becomes normal. the proliferation changes start. The mucosa thickens and the glands get enlarged. the graafian folliciles get mature.

It is caused by oestrogen and it controlled by FSH of pituitary glands. On the 15th ovulation occurse and corpus develops.

(ii) Luteal phase or Progestational phase:- It last form 15th 27th day. Mucosal layer thicknes and the glands get enlarged. The luteum grown further and attains maximum size on the 19th day and degenerates on 27th day. It is caused by progestrone. Formation of corpus lecteum and secretion of progesterone are controlled by L.H. of anterior pitutang.

(iii) Ischamic phase:- It on the 28the day in will first discharge of blood takes place. the corpus lutecum degenrates. the level of progesterone falls and it controlled by L.H. of pituitanty glands.

(iv) Menstruation phase:- It lasts for 3 to 5 days. Menstruation occurs. Blood, mucus, stripped off endometriumand an unfeetilized ovumpass out ad discharge. the main couse is the lack of progesterone.