<span>The correct answer to the question, 'which of the following scenarios is representative of how agricultural practice can affect the environment' is A. Option A is chosen because it is the only option that refer to another environment which is different from that of the farm. When fertilizers are washed to nearby ponds as a result of erosion, it causes a lot of negative changes in the pond. For instance, the chemicals in the fertilizer can be poisonous to some of the smaller organisms in the pond, this will result in the death of these organisms. Fertilizer run off can also cause excessive growth of plants such as algae in the pond. This may block out the light necessary for the survival of the organisms in the ponds and may also reduce the amount of oxygen available to the organisms living in the pond.</span>
Answer:
Explanation:
African trypanosomiasis is a parasitic disease transmitted by the tsetse fly. It gets its nickname 'sleeping sickness' because symptoms can include a disturbed sleep pattern.
Answer:
C
Explanation:
Prokaryotic cells doesn't have any nucleus, so the first one is incorrect. No cell can function without genetic information, so the last one is incorrect. Plasmids are present only in Eukaryotic cells, so the second one is incorrect. Which leaves the third one as correct.
Answer: See attached picture.
Explanation:
DNA or deoxyribonucleic acid is the name for the molecule that contains the genetic information in all living things. This molecule consists of two strands that wind around each other to form a double helix structure.
The basic unit of nucleic acids are called nucleotides, which are organic molecules formed by the covalent bonding of a nucleoside (a pentose which is a type of sugar and a nitrogenous base) and a phosphate group. So each nucleotide is made up of a pentose sugar called deoxyribose, a nitrogenous base which can be adenine (A), thymine (T), cytosine (C) or guanine (G) and a phosphate group.
<u>What distinguishes one polynucleotide from another is the nitrogenous base</u>, and thus the sequence of DNA is specified by naming only the sequence of its bases. The sequential arrangement of these four bases along the chain is what encodes the genetic information, following the following criterion of complementarity: A-T and G-C. So the sequence of these bases along the chain is what encodes the instructions for forming proteins and RNA molecules. In living organisms, DNA occurs as a double strand of nucleotides, in which the two strands are linked together by connections called hydrogen bridges.
The chemical convention of naming the carbon atoms in the pentose nucleotide pentose numerically confers the names 5' end and 3' end ("five prime end" and "three prime end" respectively). The 5'-end designates the end of a DNA strand that coincides with the phosphate group of the fifth carbon of the respective terminal deoxyribose. A phosphate group attached to the 5'-end allows the ligation of two nucleotides; for example, the covalent bonding of the 5'-phosphate group to the 3'-hydroxyl group of another nucleotide, to form a phosphodiester bond.