Purines bases are ADENINE(A) and GUANINE(G), and pirimidines bases are CITOSINE(C) and TIMINE(T).
In DNA, with ADENINE complementary base is TIMINE, and with GUANINE complementary base is CITOSINE.
The pair of nitrogenous bases that connects the complementary strands of DNA or of double-stranded RNA and consists of a purine linked by hydrogen bonds to a pyrimidine: adenine-thymine and guanine-cytosine in DNA, and adenine-uracil and guanine-cytosine in RNA.
A shell is considered as biotic (living) because it is a hard, rigid covering of many animals such as snail, sepia, pila, turtles, sea urchins. A shell is protective outer layer of these soft bodied animals. Shells are made of calcium carbonate in the form of calcite or aragonite crystallized in an organic matrix. Shells of other animals are composed of chitin, bone or cartilage. That's why a shell is considered as biotic (living).
Answer:
The correct answer is "because it came from something living".
Explanation:
In biology, a shell is defined as a protective structure of mollusks and crustaceans. A shell is considered to be biotic because it came from something living. Shells are not in fact alive as they are made of calcium carbonate and in some cases α-chitin, two non living materials. However, since mollusks and crustaceans are living beings, shells are considered biotic.
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Answer:
Halita is no more valuable than gold.
Explanation:
Halite is a sedimentary rock salt of formula NaCl. In short, halite is a salt and is neither more precious nor more valuable than gold.
As a matter of curiosity, we can say that halite is a slightly rosy white crystal, transparent, glassy, hardness 2, density 2.1 - 2.2. One of its particular properties is its salty taste. The presence of impurities can give it a reddish, brownish or even bluish or greenish tinge in case of radioactivity.
Answer:
-7x^3 -12y^2-4y
Explanation:
The -7x^3 is alone so you don't have to worry about adding or subtracting it. You add -7y^2-2y^2-4y^2+y^2 together then you just put the -4y because it's alone.