NEET Test 166

Plasmid are most widely used in genetic engineering.

Plasmids are used much more because they can replicate independent of the chromosomal DNA. Plastid is a major double-membrane organelle found in the cells of plants and algae. Mitochondria and ribosome are organelles found in the cells.

We have to know that for electrolytes, the van’t Hoff factor is the sum of the amount of ions that is found in one formula unit of the substances whereas for non-electrolytes, we can say that the van't factor is one.

We can say that expression to calculate the osmotic pressure could be given as,

Π = iMRT

We can say that,

i stands for van't Hoff factor

II stands for osmotic pressure

R stands for gas constant

M stands for molarity

T stands for temperature (in Kelvins)

We have to know that, when two solutions have the same (or) equal osmotic pressure, they are said to be isotonic in nature.

Let us now determine the van't Hoff factor and osmotic pressure for each pair of solutions.

Let d(w) and d(o) be densities of water and oil resp, then the pressure at the bottom of the tank will be

[CoF6]³⁻ is an octahedral complex.

Here, Cobalt has an oxidation state of +3.

The electronic configuration of Co³⁺ is [Ar]4s3d⁵

Therefore, there are 6 electrons in the 3d subshell.

Now, since Fluorine is not a very strong field ligand, it won't be able to cause pairing of the electrons, leaving 4 electrons in the 3d subshell unpaired.

Magnetic moment can be calculated using the formula  where n = number of unpaired electrons.

Plugging in the value of n, we get the magnetic moment

Cockroaches have two pairs of wings. The wings are attached to muscles in thorax region. One pair is hard and tough called protective wings which are not used for flight. The other pairs of wings is thin, membranous and with veins, and helps them in short flights. 

The hind wings of a cockroach, connected with tergum of metathorax help a cockroach in flying. These wings are thin, transparent and delicate structures and are also known as metathoracic wings.

The male reproductive system in cockroaches consist of a pair of testes, a pair of vas deferens, ejaculatory duct, seminal vesicle, mushroom glands, and external genitalia. Testes are present at 4^th-6^th segments while the mushroom gland is present in 6^th -7^th segments. The female reproductive system consists of a pair of ovaries, a pair of oviducts, a common oviduct i.e., vagina, genital chamber and external genitalia. The genital chamber shows the opening of spermathecae which is a storehouse of sperms. Ovaries extend from 2^th - 6^th segments and show many tubules known as ovarioles. Spermathecae is in the 6^th segment.

The alcohol that would react fastest with conc. HCl and anhydrous ZnCl₂, is 2− methylpropan −2− ol. It is a tertiary alcohol.

A mixture of conc. HCl and anhydrous ZnCl₂ is called Lucas reagent.

Primary alcohols react with Lucas reagent very slowly on heating to give alkyl chlorides. Secondary alcohols react with Lucas reagent much faster. Tertiary alcohols instantaneously react with HCl at room temperature.

Note: Lucas reagent is required for primary and secondary alcohol only.

For a body that moves in a circular path, the displacement and the centripetal force are perpendicular to each other. Thus, the work done or accomplished by the centripetal force is zero.