Final answer:
Ribosomes in eukaryotes are composed of a small 40S subunit and a large 60S subunit, forming an 80S ribosome. In prokaryotes, the ribosome is 70S and composed of a 30S subunit and a 50S subunit. Eukaryotic organelles have 70S ribosomes similar to prokaryotic ribosomes.
Step-by-step explanation:
Ribosomes are organelles responsible for protein synthesis in cells. In eukaryotes, ribosomes are composed of a small 40S subunit and a large 60S subunit, which combine to form an 80S ribosome in the cytoplasm and rough endoplasmic reticulum. The small subunit binds to the mRNA template, while the large subunit binds to tRNAs. In contrast, prokaryotes have 70S ribosomes composed of a 30S subunit and a 50S subunit. Eukaryotic organelles such as mitochondria and chloroplasts have their own 70S ribosomes, similar in size to prokaryotic ribosomes.