The detritus food chain (DFC) has at the first tropic level.

Which of the following is not a cyanobacteria ?

The blastocyst becomes embedded in the endometrium of the uterus. This is called :

Observe the figure and answer the following:

The given diagram represents stages (A-E) of development of the embryo sac in angiosperms. Which of the following correctly identifies the structure labelled (ii), (iii), (iv), (v), and (vi) in figure E?

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 one of the following is not the cellular barrier of innate immunity?

Read the following passage carefully.
Restriction enzyme
Restriction enzymes cut the strand of DNA a little away from the center of the palindrome sites, but between the same two bases on the opposite strands. This leaves single stranded portions at the ends. There are overhanging stretches called sticky ends on each strand. These are named so because they form hydrogen bonds with their complementary cut counterparts. This stickiness of the ends facilitates the action of the enzyme DNA ligase. The word palindromes refer to group of letters that forms the same words when read both forward and backward. Restriction endonucleases are used in genetic engineering as molecular scissors.
Which one of the following enzyme helps to join DNA?

Which one of the followings is an example of ex situ conservation?

If \(A=\left[\begin{array}{cc}2 & 3 \\ -1 & 1\end{array}\right]\) and \(A^2-3 A+k I=0\), then the value of \(k\) is:

Arrange the following compounds in increasing order of their boiling points.
(A) Bromomethane \(\left( CH _3 Br \right)\)
(B) Bromoform \(\left( CHBr _3\right)\)
(C) Chloromethane \(\left( CH _3 Cl \right)\)
(D) Dibromomethane \(\left( CH _2 Br _2\right)\)
Choose the correct answer from the options given below:

Which of the following matrix is not skew symmetric matrix?

Let \(F(z)\) be the cumulative density function of the standard normal variate \(Z\), then which of the following are correct?
(A) \(F(z)=\frac{1}{\sqrt{2 \pi}} \int_{-\infty}^z e^{-t^2 / 2} d t,-\infty<Z<\infty\)
(B) \(F(-Z)=1-F(Z)\)
(C) \(F(0)=0\)
(D) \(F(\infty)=1\)
Choose the correct answer from the options given below:

Which of the following reagents are used for denaturation of alcohol

Read the passage carefully and answer the questions given along
Our immune system plays the major role in preventing diseases when we are exposed to disease-causing agents. Immunity is of two types: (i) Innate immunity and (ii) Acquired immunity. The human immune system consists of lymphoid organs, tissues, cells and soluble molecules like antibodies. The immune system also plays an important role in allergic reactions, auto-immune diseases and organ transplantation. The primary lymphoid organs are bone marrow and thymus. The secondary lymphoid organs are spleen, lymph nodes, tonsils, Peyer's patches of small intestine and appendix. There is lymphoid tissue also located within the lining of the major tracts (respiratory, digestive and urogenital tracts) called mucosa associated lymphoid tissue (MALT). It is important to note that HIV/AIDS is not spread by mere touch or physical contact; it spreads only through body fluids. AIDS has no cure, prevention is the best option. Adolescence is accompanied by several biological and behavioural changes and surveys and statistics show that use of drugs and alcohol has been on the rise especially among the youth. Factors associated with drug and alcohol abuse among adolescents are a child's natural curiosity, stress, the perception among youth that it is 'cool' or progressive to smoke, media exposure and an unstable or unsupportive family structures and peer pressure. It is best to identify the situations that may push an adolescent towards use of drugs or alcohol, and to take remedial measures well in time.
Active immunization is most suitable method for: