Question

proteins are molecules within an organisms body that carry out a variety of functions. the creation of proteins within the body is directed by the genetic code of an organism, also known as their dna. these protein molecules are made of smaller building blocks known as amino acids, and code for the different traits that an organism has. the more amino acids that two organisms have in common, (they must also be in the same order) the more similar their proteins are, the more related they are. we abbreviate the full names of amino acids with three - letter codes. example: leucine = leu
answer the questions below using the information from the reading.

1. what is dna the instructions to build? ____________
2. what molecules are amino acids used to build within an organisms body? ____________
3. which of the following organisms is most related to humans? compare the amino acid sequences to determine which organism has the most in common.

human amino acid sequence	ile - leu - ala - asp - arg
dolphin amino acid sequence	ser - leu - ala - asp - arg
lizard amino acid sequence	ile - gly - ala - ser - leu

Explanation:

Step1: Find answer for question 1

The text states that the creation of proteins within the body is directed by DNA. So DNA is the instructions to build proteins.

Step2: Find answer for question 2

It is mentioned that protein molecules are made of smaller building - blocks known as amino acids. So amino acids are used to build proteins.

Step3: Find answer for question 3

Compare the amino - acid sequences. The human sequence is ILE - LEU - ALA - ASP - ARG. The dolphin sequence is SER - LEU - ALA - ASP - ARG, which has 4 out of 5 amino acids in common with humans (LEU, ALA, ASP, ARG). The lizard sequence is ILE - GLY - ALA - SER - LEU, which has fewer in common. So the dolphin is most related to humans.

Answer:

1. Proteins
2. Proteins
3. Dolphin