Noncoding RNAs (RNAs that do not encode proteins),
especially micro-RNAs (miRNAs), play a critical role in tumorigenesis.

#Id: 7733

#Unit 1. Molecules and their Interaction Relevant to Biology

Atoms are made of the same three basic particles: protons, neutrons, and electrons.

#Id: 7734

#Unit 1. Molecules and their Interaction Relevant to Biology

The number of electrons in a neutral atom is equal to the number of protons.

#Id: 7735

#Unit 1. Molecules and their Interaction Relevant to Biology

The mass number of the atom (M) is equal to the sum of the number of protons and neutrons in the nucleus.

#Id: 7736

#Unit 1. Molecules and their Interaction Relevant to Biology

The number of neutrons is equal to the difference between the mass number of the atom (M) and the atomic number (Z).

#Id: 7737

#Unit 1. Molecules and their Interaction Relevant to Biology

Calculate the number of electrons, protons and neutrons in 1 mole of 16^O^-2 ions.

#Id: 7738

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following are true for an element?

(i) Atomic number = number of protons + number of electrons

(ii) Mass number = number of protons + number of neutrons

(iii) Atomic number = number of protons = number of neutrons

(iv) Atomic number = number of protons = number of electrons

(a) (i) and (ii)

(b) (i) and (iii)

(c) (ii) and (iii)

(d) (ii) and (iv)