Translation

The first phase of translation is the activation of amino acids in the presence of ATP and their linking to their cognate tRNA. This process is called charging of tRNA or aminoacylation of tRNA. (Binding of mRNA to the ribosome happens later, at initiation.)

The ribosome has two subunits; in bacteria the large (50S) subunit contains 23S rRNA and 5S rRNA.
The formation of the peptide bond between two amino acids is catalysed by the 23S rRNA of the large subunit, which acts as the enzyme peptidyl transferase.
An RNA molecule that acts as an enzyme is called a ribozyme; the 23S rRNA is the ribozyme of bacteria.
5S rRNA is only a structural component of the ribosome.
snRNA and hnRNA occur in eukaryotic nuclei (splicing and precursor of mRNA) and are not found in bacteria.
Hence the 23S rRNA also acts as a catalyst in a bacterial cell.

During protein synthesis a single mRNA molecule can be translated by many ribosomes at the same time.
Several ribosomes attach one after another to a single mRNA strand and move along it, each one synthesising a copy of the same polypeptide.
This chain of ribosomes held together by one mRNA is called a polyribosome or polysome.
The polysome increases the efficiency of translation, because many copies of a polypeptide are produced from one mRNA in a short time.
The ribosomes of a polysome are not joined directly to each other, and attachment to the endoplasmic reticulum is not what defines a polysome.
So a polysome is formed by several ribosomes attached to a single mRNA.

The genetic information in DNA is first copied into messenger RNA (mRNA) by transcription.
The mRNA carries this information as a sequence of codons, each codon being a triplet of nucleotides that specifies one amino acid.
During translation the ribosome reads the codons of the mRNA one after another, so the sequence of nucleotides in the mRNA decides the sequence of amino acids in the polypeptide.
tRNA is only the adapter molecule that brings the correct amino acid by recognising the codon through its anticodon.
rRNA is a structural and catalytic component of the ribosome.
cDNA is a DNA copy made from mRNA in the laboratory and does not take part in protein synthesis in the cell.
So the amino acid sequence is decided by the sequence of mRNA.

Initiation of translation in prokaryotes takes place in steps, with the help of initiation factors IF1, IF2 and IF3.
First the 30S subunit (with IF3) binds to the mRNA at the Shine–Dalgarno sequence. This step does not need GTP.
Next, the initiator tRNA (fMet-tRNA$^{fMet}$) is brought to the start codon AUG on the 30S–mRNA complex by IF2, which is bound to GTP (IF2–GTP–fMet-tRNA). So GTP is needed for the association of fMet-tRNA with the 30S–mRNA complex, forming the 30S initiation complex.
Finally the 50S subunit joins; the GTP bound to IF2 is hydrolysed to GDP + $P_i$ at this time, and the initiation factors are released.
Formation of formyl-met-tRNA (charging and formylation) uses ATP, not GTP.
So, as per the answer key, GTP is needed in the association of the 30S–mRNA complex with formyl-met-tRNA.