Completion of the first meiotic division of the primary oocytes takes place -

Microbes in human welfare Microbes are a very important component of life on earth. we use microbes and microbially derived products almost every day, like LAB to make curd, yeast to make bread, adding flavor and texture to cheese, producing antibiotics etc. The addition of LAB, improves the milk quality by increasing vit. B12. Cheese is one of the oldest food items in which microbes are used. For example, large holes in Swiss cheese are due to CO2 produced by the bacterium Propionibacterium sharmanii. The BOD test measures the rate of uptake of oxygen by microorganisms in a sample of water and thus, indirectly, BOD is a measure of the organic matter present in the water. The greater the BOD of waste water, the more is its polluting potential. In anaerobic sludge digesters, bacteria produce a mixture of gases like methane, hydrogen sulphide and carbon dioxide. These gases form biogas and can be used as a source of energy. Biofertilisers are organisms that enrich the nutrient quality of the soil. The main sources of biofertilisers are bacteria, fungi and cyanobacteria. You have studied about the nodules on the roots of leguminous plants formed by the symbiotic association of Rhizobium. These bacteria fix atmospheric nitrogen into organic forms, which is used by the plant as a nutrient. Other bacteria can fix atmospheric nitrogen while free-living in the soil (examples Azospirillum and Azotobacter).
In anaerobic sludge digesters, the biogas produced by the bacteria, is composed of -

Arrange the steps involved in creating pest-resistant transgenic plants
using RNA interference (RNAi).
(A) Binding of complementary RNAs to form double-stranded RNA
(dsRNA).
(B) Formation of sense and antisense RNA in the host cells.
(C) Silencing of specific mRNA of the nematode.
(D) Introduction of nematode-specific genes into the host plant using
Agrobacterium vectors.
Choose the correct answer from the options given below:

Match List-I with List-II

List-I	List-II
Evolutionary stages of human species	Time of origin
(A) Ramapithecus	(I) About 1.5 million years ago
(B) Australopithecines	(II) About 15 million years ago
(C) Homo erectus	(III) Between 100,000 - 40,000 years ago
(D) Neanderthal man	(IV) Two million years ago

Choose the correct answer from the options given below:

Identify the terminal methods to prevent pregnancy.
(A) Tubectomy
(B) Vasectomy
(C) IUDs
(D) Cervical caps
Choose the correct answer from the options given below:

The brain size of Neanderthal man was :

Chasmogamous flowers are -

A network of resistors is connected as shown in the figure. The potential drop across 4\(\Omega\) resistors is

Which of the following will produce turbidity most readily when treated with conc. HCl in presence of anhydrous \(ZnCl _2\) (Lucas reagent)?

Observe the given figure and answer the following questions:

Which of the following are not part of Innate immunity?
(A) Skin and acid in stomach
(B) B-Lymphocytes
(C) IgE and IgG
(D) Tears from eyes

Match List-I with List-II

List - I	List - II
A. Activation Energy	I. Difference in the energy of activated complex and reactants
B. Threshold Energy	II. Minimum Energy possessed by reactant molecules to form effective collisions
C. Heat of Reaction	III. Negative for exothermic reaction
D. Role of a catalyst	IV. To give new path of reaction

Choose the correct answer from the options given below :

The radius of the inner most electron orbit of a hydrogen atom is 0.53 Å. What is the radius of orbit of \(2^{\text {nd }}\) excited state ?

Which of the following statements are TRUE?
(A) The variable \(t\) of \(t\)-distribution ranges from \(-\infty\) to \(\infty\).
(B) The probability curve of the \(t\)-distribution is symmetric about the line \(t=0\)
(C) The variance of the \(t\)-distribution is greater than one.
(D) As the number of degrees of freedom decreases, the \(t\)-distribution curve moves closer to the standard normal probability curve.
Choose the correct answer from the options given below :