IBDP Online Test Series By iitianacademy
Comprehensive Test Preparatory package targeted towards IBDP
Which structure found in eukaryotes has a single membrane?
A. Nucleus
B. Lysosome
C. Chloroplast
D. Mitochondrion
▶️Answer/Explanation
Markscheme
B
Lysosomes are organelles found in eukaryotic cells that contain digestive enzymes enclosed within a single membrane. They are involved in breaking down and digesting cellular waste materials, foreign substances, and cellular debris. The enzymes inside lysosomes are able to break down various biomolecules, including proteins, lipids, carbohydrates, and nucleic acids.
Which is a valid comparison between prokaryotic and eukaryotic DNA?
▶️Answer/Explanation
Markscheme
B
A valid comparison between prokaryotic and eukaryotic DNA is that both contain genetic information in the form of nucleic acids, but prokaryotic DNA is circular and not enclosed within a nucleus, whereas eukaryotic DNA is linear and enclosed within a nucleus. In addition plasmids are small, circular, double-stranded DNA molecules that are found in bacteria and some eukaryotic cells. They are separate from the bacterial chromosome and can replicate independently. Plasmids often carry genes that are not essential for bacterial survival, but can provide advantages such as antibiotic resistance or the ability to produce toxins.