Natural selection. The trait that is unfavorable to the baby giraffe's survival will cause the death of giraffes with that specific gene that is responsible for a short neck vs a long neck. Natural selection causes traits that help the survival of the species will be carried throughout generations while unfavorable traits will be lost.
The answer to this statement is true. It is because the size
the total amount of the DNA that it contains makes up the size of the genome.
Therefore, the size of the genome determines the information that it contains
such as the DNA.