Answer:
B. It's much harder to provide the right atmospheric environment to cultivate obligate anaerobes, so it's been harder to study them.
Explanation:
Obligate anaerobic bacteria are the ones that can grow only in the absence of oxygen. These bacteria do not derive the energy from aerobic cellular respiration and die when exposed to the presence of oxygen.
Owing to their oxygen sensitivity, the culturing of obligate anaerobic bacteria requires special equipment to ensure the absence of oxygen.
The presence of aerobic conditions in laboratories makes their culture and study harder than that of the aerobic or facultative anaerobic bacteria.
Answer:
The correct answers are "The population of birds with large beaks will increase on the island" and "The trait for large beaks will be passed on to future generations through natural selection".
Explanation:
Natural selection functions under the premise of survival of the fittest, where stressful situations such as lack of resources will select the organisms with advantageous traits. In this case, the decrease on seeds affected particularly the numbers of small, soft seeds over large, hard seeds. This stressful situation will select the finches with the advantageous trait of having large beaks, because they are able to feed from large, hard seeds. This trait will be passed on to future generations through natural selection, which eventually will result in the population of birds with large beaks will increase on the island.
Answer:
DNA: Three nucleotides encode an amino acid. Proteins are built from a basic set of 20 amino acids, but there are only four bases. Simple calculations show that a minimum of three bases is required to encode at least 20 amino acids.
RNA: You can think of the sequences of bases in the coding strand of DNA or in messenger RNA as coded instructions for building protein chains out of amino acids. There are 20 amino acids used in making proteins, but only four different bases to be used to code for them. Obviously one base can't code for one amino acid.
Answer:
Deoxyribose, found in DNA, is a modified sugar, lacking one oxygen atom (hence the name "deoxy"). This difference of one oxygen atom is important for the enzymes that recognize DNA and RNA, because it allows these two molecules to be easily distinguished inside organisms.
Explanation:
The answer to this question is B.
