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3 years ago

Which is the most accurate description of an ecosystem?

2 answers:

6 0

Its C because there are both abiotic and biotic factors in an environment. An ecosystem consists of interactions between the physical environment and organisms.

Nikolay [14]3 years ago

4 0

C. An ecosystem consists of the biological community that occurs in some locale and the chemical factors that make up its biotic or abiotic environment.

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Please give a good description of genetic mutations. Thanks!

vivado [14]

Answer: A mutation is a change in a DNA sequence? Mutations can result from DNA copying mistakes made during cell division, exposure to ionizing radiation, exposure to chemicals called mutagens, or infection by viruses.

Explanation:

The most common genetic mutation is, In fact, the G-T mutation.

3 0

3 years ago

A protein has a molecular mass of 400 kDa when measured by gel filtration. When subjected to gel electrophoresis in the presence

RoseWind [281]

Answer:

subunit composition

how many: 4 subunits
what sizes: 160 kDa, 60 kDa, 90 kDa, and 90 kDa.

Explanation:

SDS is a detergent that denaturalizes the protein and sets a relation charge size, such as that the motion of the protein in the gel is proportional to its weight. However, the detergent can not disrupt disulfide bridges, so these bonds remain together. The bigger the protein is, the stronger interaction with the polyacrylamide gel there will be. The speed of displacement in the electromagnetic field is inversely proportional to the protein size.

On the other hand, b-mercaptoethanol acts as a reductive agent, breaking disulfide bonds. This chemical produces a complete denaturalization resulting in the unfolded protein. If disulfide bridges kept two protein subunits together, the b-mercaptoethanol separates them.

So, the most important data we need to consider here is that SDS can not disrupt disulfide bridges, while b-mercaptoethanol can.

Available data:

A protein has a molecular mass of 400 kDa
SDS → three bands with molecular masses of 180, 160, and 60 kDa
SDS + b-mercaptoethanol → three bands with molecular masses of 160, 90, and 60 kDa

SDS

180 + 160 + 60 = 400 kDa

SDS + b-mercaptoethanol

160 + 90 + 60 = 310 kDa

The difference between them is 400 - 310 = 90 kDa, meaning that there is a subunit of 90 kDa that is not being detected by SDS alone.

From both measures ( SDS and SDS/b-mercaptoethanol) we can assume that subunits 160 kDa and 90kDa are the same. So the difference is in the left subunit ⇒ 180 and 90, respectively.

180 - 90 = 90 kDa

We can assume that the 180 kDa subunit is composed of two 90 kDa subunits joined by a disulfide bridge. SDS alone could not disrupt this bond, so it detected a unit of 180kDa. b-mercaptoethanol detected this bond and broke it, generating two 90 kDa units, which migrated together in the gel, so they were expressed as the same band.

This difference suggests that the protein is formed of 4 subunits. One of them is 160 kDa, another one is 90 kDa, and the last two subunits are 90 kDa each.

3 0

3 years ago

Think about water and how it rolls up on the beach. Think of all its qualities. Is It allve according to the characteristics of

Anni [7]

No . it has no life due to the cell theory .

3 0

3 years ago

How good r animals memory.

weeeeeb [17]

Animals memories are very good especially Dolphins. Dolphins Have Longest Memories in Animal Kingdom. Marine mammals can remember their friends after 20 years apart, study says. Bottlenose dolphins (pictured in the Caribbean) have amazing memories, a new study says. Sorry, elephants: Dolphins have taken the top spot for best memory, at least for now.Aug 6, 2013

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3 years ago

Many countries, including the United States, measure output by calculating the _____.

muminat

These countries, together with the United States of America measure output through the calculation of complex indexes and metrices which, when taken together, are known as the Gross Domestic Product (GDP).

Both the economic peaks and cycles refer to other things, which are mildly related to the gross domestic product.

5 0

3 years ago

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