Arrange the given structures formed during spermatogenesis in correct sequence.
(A) Spermatozoa
(B) Secondary spermatocytes
(C) Spermatids
(D) Spermatogonia
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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.
Which one of the following options is correct for working of restriction enzymes?

Observe the diagram and answer the following questions:

Due to decrease in the number of helper T cells the AIDS patient become.

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Does the number of species in a community really matter to the functioning of the ecosystem? This is a question for which ecologists have not been able to give a definitive answer. For many decades, ecologists believed that communities with more species, generally, tend to be more stable than those with less species. According to the International Union for Conservation of Nature and Natural Resources (IUCN) (2004), the total number of plant and animal species described so far is more than 1.5 million.
Among the vertebrates, which of the following is the most species-rich group ?

Generally, an angiosperm embryo sac at maturity is -

Identify the statements which are true with respect to Euchromatin:
A. Loosely packed
B. Densely packed
C. Stains light
D. Transcriptionally active
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Identify the correct combination of intra uterine devices.
(A) Lippes loop
(B) LNG-20
(C) Saheli
(D) Multiload 375
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The solution X of the matrix equation AX = B, where A is an invertible matrix, is given by

The function \(f(x)=\left|\begin{array}{cc}x^2 & x \\ 3 & 1\end{array}\right|, x \in R\) has a:

For \(x \in R\), if \(f(x)=-(x-1)^2+2\), then
(A) f is an increasing function on \((-\infty, 1)\)
(B) ƒ has no critical points
(C) ƒ has a maximum value at x = 1
(D) ƒ has a minimum value at x = 1
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\(A\) and \(B\) are two independent events. The probability that both events \(A\) and \(B\) occur is \(\frac{1}{6}\) and the probability that neither of them occur is \(\frac{1}{3}\). If \(P(A)=x, P(B)=y\) then the value of \(x+y\) is.

Human body compensates low oxygen availability at high altitudes by:
(A) increasing number of red blood cells
(B) decreasing the binding affinity of haemoglobin
(C) increasing the binding affinity of haemoglobin
(D) increasing breathing rate
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Arrange the following transition metal ions in the increasing order of unpaired electrons.
(A) \(Cu ^{2+}\)
(B) \(Cr ^{2+}\)
(C) \(Ni ^{2+}\)
(D) \(Sc ^{3+}\)
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