Answer:
b. ecosystems in a region, species in an ecosystem, and genes and alleles in a species.
Explanation:
Biodiversity has three levels - ecosystem, species and genetic diversity. Therefore, Biodiversity can be defined as the variability among living organisms involving terrestrial, marine, and other aquatic ecosystems, genes and alleles in a species and their ecological complexes such as diversity within species, and between species of the ecosystems.
B.<span>the coded blueprint for life</span>
A nucleic acid is made of nucleotides, and nitrogenous bases are a part of a nucleotide.
DNA is a nucleic acid. The nucleotides in DNA are made up of a sugar (deoxyribose), a phosphate group, and one nitrogenous base (which will be either adenine, guanine, cytosine, or thymine).
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Answer:
The correct option is 3. "At pH 6.5 the enyzme is 50% active"
Explanation:
For the titratable group to be protonated and cause the enzyme to be in the active state, it needs to have gained a hydrogen cation (H+). In order for that to happen, there must be enough hydrogen cations in the environment of the enzyme, and hence, an acidic pH is required in this case.
With shorter necks, giraffe ancestors could not reach food-containing branches on tall trees. This resulted in the directional selection of giraffes with longer necks.
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Why is choosing a direction necessary? </h3>
It nearly appears obvious that the giraffe's long neck developed as a result of a lack of food in the lower branches of trees. The giraffe has a significant advantage because it is taller than any other mammal and can feed where few others can.
When compared to modern giraffes, the giraffe's ancient predecessors had a shorter neck. The plants that were lying at a higher level were inaccessible to them. Giraffe phenotypes have changed in various ways, and now have long necks to reach vegetation that is higher up. The extreme form is chosen above other features in directional selection. It was decided to choose the long-necked giraffe over the short-necked.
To know more about direction selection for longer necked giraffes visit:
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