Answer:
Nitrogen
Explanation:
The nitrogenous bases of the two separate polynucleotide strands are bound together, according to base pairing rules (A with T and C with G), with hydrogen bonds to make double-stranded DNA.
An isolated colony on a selective medium is not considered a pure culture because inhibited organisms might be masked by the colonies. This statement is true.
On the basis of their constitution or usage, culture media can be classified into various groups; these include defined, complex, selective, as well as enrichment medium.
A selective medium consists of dyes or noxious substances/chemicals which inhibit the growth of specific microorganisms but promote the growth of other microbes.
A pure culture is a laboratory culture which contains a single species of microorganism. It is free from other microorganisms.
Since selective media affects the growth of distinct organisms differently, therefore, an isolated colony formed in such type of medium is not considered a pure culture.
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Answer:
Explanation: Collenchyma cells are elongated cells with unevenly-thickened walls. They provide structural support, mainly to the stem and leaves.
Answer:
C) Weathering and erosion
Explanation:
The completed sentence will be as follows -
The deserts and dunes seen here are created through the process of Weathering and Erosion.
Weathering is defined as the process of breakdown of rocks, soil and minerals into small particles under the influence of atmosphere, water and also biological organisms to some extent. The products of weathering are found at same place as the original rock with little or no movement.
In erosion, the materials such as rocks and soil or dissolved materials are transported from one place to the another place by the action of wind or water flow. So, here displacement of substances takes place.
