Question

multiple choice question
what property is shared by archaeal and bacterial ribosomes?

both are enclosed in membranes.
both have 50s and 30s subunits.
both have 60s and 40s subunits.
both have dna in the active site.

Explanation:

1. Analyze Option 1: Ribosomes (in archaea and bacteria) are not membrane - enclosed. Eukaryotic organelles like mitochondria have membrane - enclosed ribosomes, but prokaryotic (archaeal and bacterial) ribosomes are free in the cytoplasm. So this option is incorrect.
2. Analyze Option 2: Archaeal and bacterial ribosomes (prokaryotic ribosomes) are 70S ribosomes, which are composed of a 50S large subunit and a 30S small subunit. This is a characteristic shared by both archaeal and bacterial ribosomes.
3. Analyze Option 3: 60S and 40S subunits are part of 80S ribosomes, which are found in eukaryotic cells, not in archaeal or bacterial (prokaryotic) cells. So this option is incorrect.
4. Analyze Option 4: Ribosomes are involved in protein synthesis and use RNA (rRNA) in their structure. They do not have DNA in their active site. So this option is incorrect.

Answer:

B. Both have 50S and 30S subunits.