Fresh water is any body of water with a low salt concentration. Organisms in fresh water various challenges which includes; Osmotic concentration such that fresh water is permanently dilute and most cells cannot function at this concentration of ions. Varying temperatures, variation in oxygen levels and reproduction and life cycle due to permanence of habitat and physiological difficulty of regulating osmotic concentration in larvae and juveniles.
Chromatin
Chromosome, the highest packing level of DNA, is packed in nucleus. DNA strand itself is packed in chromatin. Chromatin is DNA packaging into 30nm fibers that involve DNA strand with scaffolding around DNA proteins, like histones, in eukaryotic cells’ nucleus.
Explanation:
The DNA strand is folded into nucleosomes, bead-like structures on the DNA and fold up into the 30nm fibers. During meiosis and mitosis, the chromatin is super-coiled up into thicker fibers called chromosomes. Chromosomes within the nucleus can be viewed by a light microscope in a cell in metaphase.
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For more on levels of DNA check out;
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Answer:
The correct answer will be option-B.
Explanation:
Deoxyribose nucleic acid or DNA is the genetic material of the organism which is made up of nucleotide monomer. The structure of DNA is made up of two strands of nucleotides coiled in a helical structure thus providing a double-helical shape to the structure.
Each nucleotide of a strand is composed of a five-carbon sugar, phosphate group and nitrogenous bases. These molecules are arranged in anti-parallel fashion in DNA which provides the polarity to the DNA strand. One strand is read from the 5' to 3' direction whereas another form 3'to 5' direction.
Thus, Option-B is the correct answer.
They are well at surviving because of their thick white coat. The white fur helps them blend in with the snow and ice. The polar bear also has a layer of fat under their skin so they can survive harsh temperatures.
I believe the answer would be 20 amino acids