Practice 1: What is so important about DNA? Select all correct answers. A. DNA is found in all organisms and carries instructions to build those organisms B. DNA found in one organism probably shares similar instructions found in another species C. DNA is composed of only four bases that repeat in a sequence that is different for each species D. Some organisms don’t actually have DNA E. The DNA of each organism is made out of different types of chemical

Answer:

A. DNA is found in all organisms and carries instructions to build those organisms - Correct. DNA contains the genetic instructions that are necessary for the development, functioning, growth, and reproduction of all known organisms and many viruses.

B. DNA found in one organism probably shares similar instructions found in another species - Correct. All organisms share a common ancestry, and thus their DNA contains similarities. This is why certain genes are conserved across species.

C. DNA is composed of only four bases that repeat in a sequence that is different for each species - Correct. DNA is made up of four types of nucleotide bases: adenine (A), cytosine (C), guanine (G), and thymine (T). The order of these bases along the DNA strand is what determines the genetic instructions.

D. Some organisms don’t actually have DNA - Incorrect. All known living organisms have DNA, with the exception of some viruses that contain RNA instead.

E. The DNA of each organism is made out of different types of chemicals - Incorrect. The DNA of all organisms is composed of the same basic chemical structure; the difference lies in the sequence of the bases and not the chemical composition of the DNA itself.