Question

select the true statements. copies of the genetic instructions for proteins are carried by molecules of rna from the nucleus to the ribosomes. there are only three different types of dna nucleotides. each species uses its own genetic code. within a gene, each group of four nucleotides specifies a particular amino acid.

Explanation:

1. In transcription - translation process, messenger RNA (mRNA) carries genetic information from DNA in the nucleus to ribosomes for protein synthesis, so the first statement is true.
2. There are four types of DNA nucleotides (adenine - A, thymine - T, guanine - G, cytosine - C), so the second statement is false.
3. The genetic code is nearly universal across species, so the third statement is false.
4. In a gene, each group of three nucleotides (codon) specifies a particular amino - acid, not four, so the fourth statement is false.

Answer:

Copies of the genetic instructions for proteins are carried by molecules of RNA from the nucleus to the ribosomes.