A sugar-phosphate backbone (alternating grey-dark grey) joins together nucleotides in a DNA sequence. The sugar-phosphate backbone forms the structural framework of nucleic acids, including DNA and RNA. This backbone is composed of alternating sugar and phosphate groups, and defines directionality of the molecule.The two strands run in opposite directions, one going in a 3' to 5' direction and the other going in a 5' to 3' direction. The nitrogenous bases are positioned inside the helix structure like "rungs on a ladder," due to the hydrophobic effect, and stabilized by hydrogen bonding.
Uracil is one of the four nucleobases in the nucleic acid of RNA that are represented by the letters A, G, C and U. The others are adenine, cytosine, and guanine. In RNA, uracil binds to adenine via two hydrogen bonds. In DNA, the uracil nucleobase is replaced by thymine. Uracil is a demethylated form of thymine.
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A major study has shed new light on the dim layer of the ocean called the "twilight zone" -- where mysterious processes affect the ocean's ability to absorb and store carbon dioxide accumulating in our atmosphere.
The point at which the optic nerves meet and then split is termed the optic area
Answer:
D. A population with high genetic biodiversity is better able to respond to environmental stressors.
Explanation:
The genetic biodiversity of a species is the diversity of alleles that it possesses in its genetic pool. For a given gene, a population can have one or more alleles; and the more alleles the population has, it will be more diverse. Under normal conditions (without stress), the alleles that are present in high frequency in a population, are those that best respond to the environment where the population occurs. However, if some environmental condition changes and some type of environmental stress emerge (ie drought), it is possible that these alleles no longer respond equally effectively and then, it is possible that the alleles that on normal conditions occur with low frequency, are more adequate to face the stress. A population with fewer alleles (less genetic diversity) has terefore fewer options to deal with environmental stressors and<u> a population with high genetic biodiversity</u> will do this better.
The question is incomplete as it does not have the options which are:
A) chordate.
B) echinoderm.
C) nematode.
D) mollusc.
Answer:
A) chordate.
Explanation:
The animals can be distinguished based on embryonic development and are categorized into two types: Deutrostomes and the protostomes.
The deuterostomes are the organism in which the small opening in the embryo called the blastopore develops into the anus. The deuterostomes organism belongs to two groups of the animal: the echinoderms and the chordates.
The chordates are the animals which possess the bilateral symmetry that is can be divided into left and right sides and posses true cavity or coelom.
Thus, Option-A is correct.
