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C) both A and B

Correct option is B) Tsarc/zars

B) Proton is represented as P^-

B) a → 3, b → 1, c → 2

An outermost shell that has 8 electrons is said to possess an octet.

Incorrect pair is:

Samuel Crompton – Spinning Mule

Correct option is B) repels

 An atom with 8 electrons or an octet in its outermost shell is chemically stable.

A) electron do not radiate energy while rotating in discrete orbits.

• Rutherford’s model of the atom has a large empty space with a small dense, positively charged nucleus in the center. 
• According to Rutherford, electrons are revolving around the nucleus. 
• Rutherford’s model of the atom could not justify the stability of the atom.

B) nuclear model

Some small particles which are smaller than atoms are present inside the atom, called subatomic particles.

Correct option is D) Chadwick

Correct option is B) 12

Sub-atomic particles: Experiments proved that atoms were divisible and are made up of smaller particles. These particles are smaller than atoms and are present inside the atom called sub-atomic particles. The three subatomic particles are electron, proton, and neutron.

Neutrons have no charge and mass nearly equal to that of protons.

The atoms of the same element which have the same number of protons but have different numbers of neutrons are called isotopes.

Correct option is C) 8

(1) Wave speed: The distance covered by a progressive wave per unit time is called wave speed. 

(2) Frequency: The number of waves that pass per unit time across a given point of the medium is called the frequency of the wave. 

[Note : It is equal to the number of vibrations per unit time made by a particle of the medium.] 

(3) Wavelength: Wavelength is the distance between consecutive particles of the medium which are moving in exactly the same way at the same time and have the same displacement from their equilibrium positions. 

[Note : Such particles are said to be in the same phase (the same state of vibration).] 

(4) Amplitude : The magnitude of the maximum displacement of a particle of the medium from its equilibrium position is called the amplitude of the wave. 

(5) Period : The time taken for a complete wave (one wavelength long) to pass a given point in the medium is called the period of the wave.

[Note : It is equal to the periodic time of the vibrational motion of a particle of the medium.] 

(6) Wave number : The number of waves present per unit distance is called the wave number.

Correct option is A) 12.01

Correct option is A) Isotopes

A progressive wave travelling along the positive x-direction is given by y(x, t) = A sin (kx – ωt)

where A is the amplitude of the wave, k is the wave number and co is the angular frequency.

[Note : y(x, t) = A sin (kx – ωt), y(x, t) = A sin (ωt – kx), y(x, t) = A cos (kx – ωt), y(x, t) = A cos (ωt – kx) also represent a progressive wave travelling in the positive x-direction. Hence, any one of them can be used. y(x, t) can be written simply as y.]

Correct option is C) A and B

Correct option is c. CH₃⁺

Correct option is: (A) must be an odd integral multiple of λ/4.

(i) The parathyroid glands consist of four separate glands located on the posterior surface of the lobes of the thyroid gland, one pair each in the two lobes. 

(ii) The parathyroid glands secrete parathyroid hormone or parathormone, the secretion of which is regulated by the circulating calcium ion. 

(iii) Hypoparathyroidism causes the lowering of blood calcium level thereby leading to parathyroid tetany.

(i) Parathyroid hormones are under the feedback control of blood calcium level. 

(ii) A fall in blood calcium level stimulates them to secrete parathormone which restores blood calcium level. 

(iii) It increases blood calcium by drawing calcium from the bones into the plasma, by increasing calcium absorption in the digestive tract, and by reducing loss of calcium in the urine. 

(iv) It lowers blood phosphate by increasing elimination of phosphate in the urine.

Parathyroid is under the feedback control of blood calcium level. A fall in blood calcium stimulates them to secrete parathormone. A rise in blood calcium inhibits parathormone secretion from them.

The increased demand of calcium by the developing foetus stimulates secretions of parathormone, which, in turn causes increased mobilisation of bone minerals into the blood and thus softening of the bones.

Insulin controls the blood sugar level by facilitating the cellular uptake and utilisation of glucose for the release of energy.

Haemophilia A is a X-linked disease which is characterised by prolonged clotting time and internal bleeding.

The term Biotechnology was coined by Karl Ereky.

(c) Haemophilia

(c) X-chromosome

Vaccines developed by using recombinant DNA technology are called recombinant vaccines. Subunit recombinant vaccines, attenuated recombinant vaccines, DNA vaccines are the types of recombinant vaccines.

Interferons are used for the treatment of various diseases like cancer, AIDS, multiple sclerosis, hepatitis C and herpes zoster.

Interferons were discovered by Alick Isaacs and Jean Lindemann in 1957. It is classified as P and y interferons based on the structure.

Alick Issac and Jean Lindemann.

Interferons are proteinaceous, antiviral, species specific substances produced by mammalian cells when infected with viruses. They stimulate the cellular DNA to produce antiviral enzymes which inhibit viral replication and protect the cells

The Human insulin is synthesized by the (5 cells of Islets of Langerhans in the pancreas. It is formed of 51 aminoacids which are arranged in two polypeptide chains, A and B. The polypeptide chain A has 21 amino acids while the polypeptide chain B has 30 amino acids. Both A and B chains are attached together by disulphide bonds.

1. Subunit recombinant vaccines 

2. Attenuated recombinant vaccines 

3. Edible vaccines 

4. DNA vaccines

Production of insulin by recombinant DNA technology started in the late 1970s. This technique involved the insertion of human insulin gene on the plasmids of E. coli. The polypeptide chains are synthesized as a precursor called pre-pro insulin, which contains A and B segments linked by a third chain (C) and preceded by a leader sequence. The leader sequence is removed after translation and the C chain is excised, leaving the A and B polypeptide chains Explain the steps involved in the production of recombinant hGH.

Using recombinant DNA technology hGH can be produced. The gene for hGH is isolated from the human pituitary gland cells. The isolated gene is inserted into a plasmid vector and then is transferred into E. coli. The recombinant E. coli then starts producing human growth hormone. The recombinant E. coli are isolated from the culture and mass production of hGH is carried out by fermentation technology.

(c) ovarian cells

The recombinant vaccines are generally of uniform quality and produce less side effects as compared to the vaccines produced by conventional methods.

Edible vaccines are prepared by molecular pharming using the science of genetic engineering. Selected genes are introduced into plants and the transgenic plants are induced to manufacture the encoded protein. Edible vaccines are mucosal targeted vaccines which cause stimulation of both systemic and mucosal immune response. At present edible vaccines are produced for human and animal diseases like measles, cholera, foot and mouth disease and hepatitis.

Yes. The Saccharomyces cerevisiae, is the best source of recombinant interferon than E-coli. Since E-coli does not possess the machinery for glycolysation of protein.

Recombinant hepatitis B vaccine as a subunit vaccine is produced by cloning hepatitis B surface antigen (HbsAg) gene in the yeast, Saccharomyces cerevisiae.

Attenuated recombinant vaccines includes genetically modified pathogenic organisms (bacteria or viruses) that are made nonpathogenic and are used as vaccines. Such vaccines are referred to as attenuated recombinant vaccines.

Vaccines that use components of a pathogenic organism rather than the whole organism are called subunit vaccines. The advantages of these vaccines include their purity in preparation, stability and safe use.