Select the statements which are true for oogenesis?
(A). Ovulation occurs at the secondary oocyte stage.
(B). Polar body is larger than the secondary oocyte.
(C). No more oogonia is formed after birth in the ovary.
(D). The sperm and the ovum nucleus fuse before the formation of the second polar body.
Choose the correct answer from the options given below:

Read the following passage carefully and answer the given questions.
Restriction endonuclease on finding its specific recognition sequence, bind to the DNA and cut each of the two strands of the double helix at specific points in their sugar -phosphate backbones. Each restriction endonuclease recognises a specific palindromic nucleotide sequences in the DNA. Since the DNA is enclosed within the membranes, we have to break the cell open to release DNA along with other macromolecules such as RNA, proteins, polysaccharides and also lipids. This can be achieved by treating the bacterial cells/plant or animal tissue with enzymes such as lysozyme (bacteria), cellulase (plant cells), chitinase (fungus). Now a days the most commonly used matrix is agarose which is a natural polymer extracted from sea weeds. The DNA fragments separate (resolve) according to their size through sieving effect provided by the agarose gel. The first restriction endonuclease-Hind II, whose functioning depended on a specific DNA nucleotide sequence was isolated and characterised five years later. It was found that Hind II always cut DNA molecules at a particular point by recognising a specific sequence of six base pairs. In addition to 'ori', the vector requires a selectable marker, which helps in identifying and eliminating non-transformants and selectively permitting the growth of the transformants. Transformation is a procedure through which a piece of DNA is introduced in a host bacterium. Normally, the genes encoding resistance to antibiotics such as ampicillin, chloramphenicol, tetracycline or kanamycin, etc., are considered useful selectable markers for E. coli.
Transformation is a procedure through which:

Observe the figures and answer the question.

The bacteria which grow anaerobically on cellulosic material present in the digester tank of bio-gas plant is.

The net primary productivity (NPP) in an ecosystem can be represented by:

Which approach is not applied for ex situ conservation?

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?

The correct sequence of steps involved in polymerase chain reaction (PCR) are:
A. DNA polymerase is used to extends the primers using oligonucleotides.
B. Desired DNA fragments are denatured.
C. Amplified fragments are ligated with the vector for cloning.
D. Oligonucleotides are added
Choose the correct answer from the options given below:

Which reagent will distinguish Benzophenone from acetone ?

Amniocentesis should not be used for:

Identify the correct statements in the context of paramagnetic substances.
(A) In external magnetic field B, individual atomic dipole moment points in opposite direction of B.
(B) Susceptibility is small and positive.
(C) In non-uniform magnetic field, the paramagnetic bar will tend to move from weak field to strong.
(D) Examples of paramagnetic substances are Aluminium, Sodium and oxygen.
Choose the correct answer from the options given below:

There are 50 lotus plants in a pond. 20 new plants were added through reproduction. The birth rate of lotus in a year is :

Read the given paragraph and answer the given question :
Parasitism has evolved in many taxonomic groups from plants to higher vertebrates. Many parasites have evolved to be host specific in such a way that both host and the parasite tend to co-evolve. In accordance with their life styles, parasite evolve special adaptations and complex life cycle. Identify the statements which are not correct regarding host–parasite relationship:
(A) Host and parasite co-evolve.
(B) Parasite develops a main nervous system to survive.
(C) If host rejects parasite, parasite evolves counter-mechanisms to neutralize host defenses.
(D) If host rejects parasite, parasite succeeds by shifting to another host.
Choose the correct answer from the options given below:

The window of the house is in the form of a rectangle surmounted by a semi-circular portion, having a perimeter of 10 m as shown in figure.

If \(x\) and \(y\) represent the length and breadth of rectangular region, then relation between \(x\) and \(y\) is: