DNAase is an enzyme that catalyzes the hydrolysis of the covalent bonds that join nucleotides together. What would first happen to DNA molecules treated with DNAase?
A) The purines would be separated from the deoxyribose sugars.
B) The pyrimidines would be separated from the deoxyribose sugars.
C) All bases would be separated from the deoxyribose sugars.
D) The two strands of the double helix would separate.
E) The phosphodiester bonds between deoxyribose sugars would be broken.
Answer:
E) The phosphodiester bonds between deoxyribose sugars would be broken.
Explanation:
The purines and pyrimidines of two DNA strands of a DNA duplex are held together by hydrogen bonds. Hydrogen bonds are not covalent bonds. The enzyme DNAase targets the phosphodiester bonds. These are the covalent bonds that join two deoxyribonucleotides of a DNA strand together. therefore, when a DNA is subjected to digestion with DNAase enzyme, the phosphodiester bonds will be broken that hold the pentose sugars of two nucleotides by a phosphate group.
The answer is B because:
Cell walls are made of cellulose and proteins (hence II).
Animal cells don't have cell walls (only cell membrane) but plant cells do so IV
They must be semipermeable since materials for example carbon dioxide and water for photosynthesis have to go into the cell <em>some</em> way.
Answer: food chains or webs
In an ecosystem, energy from the sun is transferred by the way of food chains or webs. A food chain is a linear sequence of organisms through which food and energy is passed as one organism eats the another. A food web is the interconnection or relation of food chains. In a food chain energy is distributed among the trophic levels. Plants are primary producers which traps energy from sun for photosynthesis and belong to first trophic level in the food chain. The energy of sun present in plants is transferred to subsequent higher trophic levels when plants are consumed by other organisms.
Answer:
During pregnancy it is the eighth month I think. Sorry if it’s wrong.
Explanation:
