Explanation

 Angle in radians (θ) = Arc Length / Radius  

θ = 4 m / 2 m = 2 radians

So, the angle made at the center is 2 rad

Explanation

One up quark and two down quarks, when combined, make a neutron. 

More specifically:

A proton consists of two up quarks and one down quark (uud). 

A neutron consists of one up quark and two down quarks (udd). 

An electron and a positron are elementary particles, not composed of quarks. 

Explanation

 To calculate the bond order of O2²⁻, we need to construct a molecular orbital diagram.

The molecule has 18 electrons (12 from oxygen atoms and 6 from the negative charge).

These electrons are filled into the orbitals, starting from the lowest energy level. 

Explanation

 p24:

This protein is part of the Gag protein complex, which is responsible for forming the viral core.

The matrix is the layer surrounding the viral core, and p24 is the primary structural component of this matrix. 

gp120 and gp41:

These are glycoproteins on the surface of the HIV envelope.

They are involved in viral attachment to and entry into host cells, but not the formation of the matrix. 

Explanation

 The sex of a baby is determined by the sperm that fertilizes the egg.

If the sperm carries a Y chromosome, the baby will be a son.

If the sperm carries an X chromosome, the baby will be a daughter.

Since the chances of receiving a Y or an X chromosome are roughly equal, the probability of having a son or a daughter is approximately 50/50, or 1:1. 

Explanation

Mycoplasma is a type of bacteria, not a virus.

It lacks a cell wall, which makes it resistant to certain antibiotics.

Bacteria are capable of independent replication, unlike viruses which need a host cell. 

SARS, FIV, and HIV are all viruses:

SARS stands for Severe Acute Respiratory Syndrome,

FIV for Feline Immunodeficiency Virus,

HIV for Human Immunodeficiency Virus.

These are all viruses that infect specific hosts and require a host cell to replicate their genetic material. 

Explanation

When atomic orbitals (like s and p) mix to form hybrid orbitals (e.g., sp³, sp², sp),

The resulting orbitals have the same energy — they are degenerate.

This uniform energy level allows for equal bond strength and geometry, such as in methane (CH₄) with four sp³ orbitals.

Explanation

For an ideal gas, a graph of pressure (P) versus volume (V) at a constant temperature gives a hyperbolic curve, as described by Boyle's Law (PV = k).

This indicates an inverse relationship: as pressure increases, volume decreases, and vice versa.

However, if the graph is plotted between pressure (P) and the inverse of volume (1/V), it will be a straight line with a positive slope, passing through the origin

Explanation

The radius of an atomic orbital increases with the square of the principal quantum number (n).
So, larger values of n result in electrons being farther from the nucleus:

Radius∝n2

Explanation

 Cysteine is the only amino acid with a sulfhydryl group (-SH), which allows it to form disulfide bonds with another cysteine residue, creating a linkage between two polypeptide chains.

In insulin, disulfide bonds are crucial for maintaining its proper structure and function.