2.
Antibiotics are medicines used to fight bacteria. Traditional antibiotics prevent the formation of peptidoglycan which is required to create bacterial cell walls. As a result, bacteria burst because of the weakened cell wall and eventually die. Sometimes, people use antibiotics without a receipt of the doctor to fight a viral disease. However, antibiotics do not have any effect on viral disease development.
Why are antibiotics not effective in fighting against the virus?Deselect Answer
3.
Phylogeny is the diagram representing differences and similarities between different animal species. The less the length of the path between animals, the closer are the animal species. For example: Leopard and Domestic cat are closer to each other than Leopard and Wolf in terms of genetic similarities.
For the phylogeny below, which pair of animal species is the farthest in terms of genetic similarities?
Deselect Answer
4.
Most plants produce glucose from carbon dioxide using the Calvin cycle.
Three molecules of carbon dioxide are added to three molecules of RuBP, forming six molecules of
3-PGA. These six molecules of 3-PGA are converted to six molecules of G3P. Five molecules of
G3P are used to regenerate the three molecules of RuBP, and one molecule of G3P is produced as
an excess, and is eventually converted to glucose. One molecule of glucose requires two molecules
of G3P to produce.
Some plants have an adaptation which allows them to store carbon dioxide as another molecule,
oxalate. One molecule of oxalate can be converted back to two molecules of carbon dioxide.
How many molecules of oxalate are needed to form one molecule of glucose?Deselect Answer
5.
Many decoration statues and sculptures are made of marble, a rock consisting of calcium carbonate, CaCO3 . In recent years, many statues placed outdoors experienced heavy damage. Calcium carbonate enters into reaction with sulfuric acid and gets dissolved:
CaCO3 (insoluble solid) + H2SO4 (aqueous solution) → CaSO4 (aqueous solution) + H2O (liquid) + CO2 (gas)
H2SO4 is formed by water, H2O, and sulfur trioxide, SO3 (H2O + SO3 → H2SO4). However, sulfur
trioxide is not a usual component of the atmosphere. What can explain its unexpected occurrence in
nature?Deselect Answer
