Answer:
d. Humans and other animal hosts lack peptidoglycan cell walls.
Explanation:
Humans and other animals lack cell walls. Bacterial cells have peptidoglycan cell walls around them. The absence of cell walls in the cells of human and other animal host ensures that these cells are not affected by the drugs that target the peptidoglycan cell walls to kill or slow down the growth of the bacterial pathogen.
This makes the drugs specifically target the bacterial cells only while not affecting the host cells. If a drug would target a component present in cells of both the pathogens and hosts, the host cells would be most likely to be harmed by the drugs.
Answer:
Yes. Because:
Explanation:
Enzymes are not reactants and are not used up during the reaction. Once an enzyme binds to a substrate and catalyzes the reaction, the enzyme is released, unchanged, and can be used for another reaction.
Limestone deposits can help researchers learn about what the area was like thousands of years ago as Limestone can contain fossilized plants and animals.
Explanation:
- Limestone often contains fossils of shelled sea creatures. Entire reef formations and communities of organisms are found preserved in limestone.
- The types of fossils found in limestone include coral, algae, clams, brachiopods, bryozoa and crinoids.
- Limestone is a sedimentary rock made almost entirely of fossils.
- Fossils are the remains of ancient plants and animals, like an imprint in a rock or actual bones and shells that have turned into rock. Fossils are found in sedimentary rocks and hold the clues to life on Earth long ago.
- Limestone is composed of the mineral calcite; calcium carbonate. It often has variable amounts of silica in it, as well as varying amounts of clay, silt, and sand. Limestone rocks fall under the category of sedimentary rocks that are made from mineral calcite.
