Answer:
i don't think the vaccine will help. a lot of people died from it.
Explanation:
Answer:
The correct answer is option A. "The contents of blood come into closer contact with tissues in a closed system than an open system".
Explanation:
In a closed circulatory system, the blood has an specific path, circulating from arteries to veins and to smaller blood vessels throughout the body. This is in contrast with open circulatory systems at which the blood is not contained in arteries or veins but it suffuses the body. A closed circulatory system have many advantages over open circulatory system, however in a closed circulatory system the contents of blood are not into closer contact with tissues in than an open system. Actually, in an open circulatory system the blood is in closer contact with tissues.
Answer:
Taking into account the concepts presented in chemistry with respect to elements and compounds, it is possible to affirm that the compounds are formed by two or more elements.
Explanation:
Two or more chemical elements have the ability to bind -by forming bonds- to obtain a compound. This occurs randomly in nature.
The bonds between the elements that form a compound must be stable enough to ensure the stability of the molecule. A chemical compound can only be separated into the elements that form it by chemical processes.
The bonds types that form compounds can be:
- <em>Ionic bond.</em>
- <em>Covalent bond.</em>
- <em>Coordinated covalent bond.</em>
- <em>Metallic bond.</em>
It is necessary to mention that chemical elements are called atoms, and the bonds between them are molecules. The physical and chemical properties of a compound will be different from the properties of the elements that form it.
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brainly.com/question/2835401
Answer:
Hershey & Chase concluded. after the experiment that the genetic material that is passed from virus to the bacteria is not the protein coat but DNA. It proves the DNA is the genetic material and not the protein.
After labelling the Phage DNA and protein, Hershey and Chase performed a series of experiments like infection, blending and centrifugation. Hershey and Chase gave full evidence of the DNA being a genetic material by their experiments. To perform the experiment, Hershey and Chase have taken T-2 bacteriophage (invaders of E.coli bacteria).
Explanation:
Answer:
It is true to say that by using cuttings, exact genetic characteristics can be maintained, because the cuttings retain the same genetic information about the plant from which they were extracted.
Explanation:
Cuttings are buds or branches extracted from a plant to obtain a plant of the same species, through a type of asexual reproduction.
Once separated from the "progenitor" plant, the cutting is provided with a suitable medium for growth, and will have the possibility of growing roots, developing and growing as an independent plant, with the same genetic characteristics of the original plant, as if it were a clone.
In this reproductive process, man intervenes.
