What is bitumen? a type of clay a handle for a knife an engraved plaque a tar-like substance?

Are humans doing anything to help reverse the levels of co2 from construction

Neko [114]

Yes people are trying to plant more trees and promote awareness on afforestation and some have even started making rules the 'clean air act'

3 0

2 years ago

What does the body do during the exhaustion phase of the GAS model? It prepares to fight danger or run from it. It identifies th

ki77a [65]

It prepares to fight danger or run from it. It identifies the primary source of danger.

8 0

2 years ago

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Does facilitated diffusion use energy

alexandr402 [8]

Facilitated diffusion does not use cellular energy.

Since the transportation of molecules occurs through the concentration gradient, it doesn’t use cellular energy for transportation of molecules.

3 0

2 years ago

Do you think it is possible for scientists to incorporate chloroplasts into the skin cells of humans? What would this mean for h

Alisiya [41]

Similarly to mitochondria on which the animals and fungi rely upon, the chloroplasts are the solar-power plants of the plant cell. With the advancement in the field of genetics and biotechnology, it may be feasible for scientists to incorporate chloroplasts into human skin cells. However, there may be few issues, which the human beings would have to encounter with, these are as follows:

1. The immune system of the humans may attack the chloroplasts, but maybe they would be safe if they are present within the cell.

2. As the skin of the humans would be undergoing the process of photosynthesis, then they would have to be in green color, thus, the melanocytes of the skin would have to be engineered in order to generate another pigment.

3. The humans may get skin cancer and sunburns when they would be out feeding on sunlight, that is, the ultraviolet part of the sunlight would cause the destruction of the living cells.

4. In order to undergo the reaction of photosynthesis, the humans would require more water than usually required by a normal human being, and this could be a disadvantage in a desert surrounding.

5. The process would not help to generate much energy for an active species like humans, as the daily energy requirements for a human being would be attained by absorbing around 10000 kJ of energy, that is, around 150 hours in a day of sitting in the Sun, which is impossible.

3 0

3 years ago

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The data obtained from the meselson–stahl experiment after one generation of replication eliminated the dispersive model of dna

Sedaia [141]

<h2>Given statement is false</h2>

Explanation:

According to dispersive model of DNA replication,DNA molecules are hybrids of parental and daughter DNA;In this model each individual strand is a combination of original and new DNA

Meselson and Stahl did an experiment on DNA replication using E.coli bacteria

E.coli was grown in a medium containing heavy isotope of nitrogen,bacteria took up the nitrogen and used to synthesize new biological molecules,including DNA
It was grown for many generations,the nitrogenous bases of the bacteria's DNA were all labelled with heavy nitrogen
Bacteria were then switched to light nitrogen isotope and allowed to grow for several generations
They then measured the density of the DNA using density gradient centrifugation
This method separates molecules such as DNA into bands by spinning them at high speeds in the presence of another molecule, such as cesium chloride
Each DNA produced two DNA molecules each with one new strand and one old strand called semi conservative replication(half of the parental DNA conserved in daughter DNA)
Each DNA strand act as a template for synthesis of new strand
Hence,dispersive model of DNA was eliminated and semi-conservative model of DNA replication was proved by the above experiment

3 0

3 years ago

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