Arrange the following cells according to their order of development in testis during spermatogenesis.
(A) Secondary spermatocytes
(B) Spermatids
(C) Primary spermatocytes
(D) Spermatogonia
Choose the correct answer from the options given below:

Find the odd one out among the following structures?

ABO blood groups are controlled by the -

Read the passage carefully and answer the given questions.
Recombinant DNA Technology
Asexual reproduction preserves the genetic information, while sexual reproduction permits variation. Traditional hybridization procedures used in plants and animals breeding very often lead to inclusion and multiplication of undesirable genes along with the desired genes. The techniques of genetic engineering, which include creation of recombinant DNA, use of gene cloning and gene transfer, overcome this limitation and allow us to isolate and introduce only one or a set of desirable genes without introducing genes into the target organism.
In Recombinant DNA Technology, what is the role of the "selectable marker gene"?

Read the following paragraph carefully and answer the given questions.
Certain types of leukocytes (WBC) of our body like polymorpho-nuclear leukocytes (PMNL-neutrophils) and monocytes and natural killer (type of lymphocytes) in the blood as well as macrophages in tissues can phagocytose and destroy microbes. For determining the cause of allergy, the patient is exposed to or injected with very small doses of possible allergens, and the reactions studied. The use of drugs like anti-histamine, adrenalin and steroids quickly reduce the symptoms of allergy. Heroin, commonly called smack is chemically diacetylmorphine which is a white, odourless, bitter crystalline compound. This is obtained by acetylation of morphine. Techniques like radiography (use of X-rays), CT (computed tomography) and MRI (magnetic resonance imaging) are very useful to detect cancers of the internal organs. Different species of Plasmodium (P. vivax, P. malaria and P. falciparum) are responsible for different types of malaria. Of these, malignant malaria caused by Plasmodium falciparum is the most serious one and can even be fatal.
Which of the following technique is not very useful to detect the cancers of internal organs?

Which one of the following equation represent Verhulst Pearl Logistic Growth?

Meiotic division taking place during oogenesis is an unequal division resulting in the formation of a:

Sickle-cell anaemia is:

About ______ the first cellular forms of life appeared on earth.

\(\left[ Cu ( en )_2\right]^{2+}\) is more stable than \(\left[ Cu \left( NH _3\right)_4\right]^{2+}\) because

The self inductance of an inductor does not depend on the :

Calculate the magnetic moment (spin-only) of a trivalent ion in aqueous solution if its atomic number is 22 .

For a series LCR circuit, \( R = X_L = 3X_C \). The impedance of the circuit and the phase difference between voltage V and current I, respectively, will be: