NEET Test 137

The correct increasing order of ionisation enthalpy is B < S < P < F.

Ionization enthalpy in a period increase from left to right and decrease on going down the group. So fluorine will have the highest ionisation energy and boron will have the lowest. Between S and P, phosphorus has the higher ionisation energy due to its half-filled electronic configuration.

The central nervous system is a part of the nervous system that controls and regulates all functions of multicellular animals. In bony organisms, the nervous system engages in meninges. It covers most of the nervous system and the brain and spinal cord or spinal cord. The nervous system is located in the dorsal cavity, in which the brain is in the cranial cavity and the spinal cord is in the spinal cavity. The brain is protected by the skull and by the spinal bones. The grey matter is composed of nerve cells, nerve fibers, and neuroglia, which are nonmyelinated, while white matter consists mostly of myelinated axons.

Yuccas have a very specialized, mutualistic pollination system, being pollinated by yucca moths (family Prodoxidae), the insect transfers the pollen from the stamens of one plant to the stigma of another, and at the same time lays an egg in the flower, the moth larva then feeds on some of the developing seeds, always leaving enough seed to perpetuate the species. 

Free central is found in syncarpous gynoecium. In it, the ovary is unilocular and the ovules are borne on the axis in the center of the ovary. The septum is absent in the ovary.  For example, Primrose, Dianthus (Caryophyllaceae).

Aqua regia is a mixture of nitric acid and hydrochloric acid, optimally in a molar ratio of 1:3. Aqua regia is a yellow-orange fuming liquid.  It can dissolve the noble metals gold and platinum.

DNA replication is the biological process of producing two identical replicas of DNA from one original DNA molecule. The DNA replication process uses DNA polymerase III to catalyze the joining of deoxyribonucleoside 5′-triphosphates (dNTPs) at a growing chain of DNA. DNA is read by DNA polymerase in the 3′ to 5′ direction, meaning the new strand is synthesized in the 5' to 3' direction.

• In the DNA replication process, one new strand (leading strand) is made as a continuous piece. The other (lagging strand) is made in small pieces.
• At the leading strand, DNA polymerase III synthesizes the new strand in the 5′ to 3′ direction.
• The lagging strand is elongated in an antiparallel direction, by the addition of short RNA primers (Okazaki fragment) which are filled with other joining fragments.
• As explained above during DNA replication RNA Primer is removed by DNA polymerase I.

DNA replication is semiconservative, meaning that each strand in the DNA double helix acts as a template for the synthesis of a new, complementary strand. DNA Polymerase I possess a 3´→5´ exonuclease activity or "proofreading" function, which lowers the error rate during DNA replication.

Other Important Enzymes in DNA Replication:

The solubility of sulphates in water decreases on moving down the group BeSO₄ and MgSO₄ are fairly soluble in water while BeSO₄ is completely insoluble.

This is due to increases in lattice energy of sulphate down the group which predominates over hydration energy.

Order of solubility of sulphates:

BeSO₄​ > MgSO₄ > CaSO_4​ > SrSO₄ > BaSO₄