Is it risky using hair spray as a flame thrower?

17. Which of the following examples of an ecological effect leading to an evolutionary effect is most correct? A) When seeds are

dusya [7]

Answer:

The correct option is C.

Explanation:

Evolution refers to the gradual development of living organisms from earlier forms to the forms that exist today. One of the principal factors that lead to evolution is the ability of an organism to adapt to adverse changes in its environment. Organisms that are able to survive adverse changes in their environments usually go on to produce offspring that possess their parents' ability to survive. A good example of this is given in option C, where individuals with denser fur were able to survive from severe cold and then give birth to young ones that inherit their parents' ability to survive severe cold.

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3 years ago

The DNA molecule is conformed by a sugar named: _______________, a ___________________ and a _______________ ______________ (___

babunello [35]

A phosphate group and single nitrogen containing based

3 0

3 years ago

Water can evaporate through stomata?

Ahat [919]

Yes. the stomata has small openings found at the bottom of the leaves

4 0

3 years ago

Read 2 more answers

Many athletes inhale pure oxygen after exercise in an attempt to increase muscular re-absorption of oxygen. Measured continuousl

koban [17]

Answer:

A

Explanation:

4 0

3 years ago

One of your lab partners has followed the recommended procedure of running Gram-positive and Gram-negative control organisms on

andreyandreev [35.5K]

Answer:

Reduced in holding time of decolrization step and also used less Alcohol because decolrization step is important in Gram's staining.The decolorization step must be performed carefully. Otherwise over-decolorization may occur. This step is critical and must be timed correctly otherwise the CV stain will be removed from the Gram-positive cells. If the decolorizing agent is applied on the cell for too long time, the Gram-positive organisms to appear Gram-negative..

Explanation:

Gram' staining is a technique used in microbiology labs to differentiate between Gram's positive and negative

Gram-positive bacteria :Stain dark purple due to retaining the primary dye called CV in the cell wall.

:Gram-negative bacteria Stain red or pink due to retaining the counter staining dye called Safranin or neutral red.

There are four basic step in Gram" staining

1) Application of the Primary Stain to a Heat-Fixed Smear of Bacterial Culture

2)Addition of Gram's Iodine

3)Decolorization with 95% Ethyl Alcohol:Alcohol or acetone dissolves the lipid outer membrane of Gram-negative bacteria, thus leaving the peptidoglycan layer exposed and increases the porosity of the cell wall. The CV-I complex is then washed away from the thin peptidoglycan layer, leaving Gram-negative bacteria colorless.

On the other hand, alcohol has a dehydrating effect on the cell walls of Gram-positive bacteria that causes the pores of the cell wall to shrink. The CV-I complex gets tightly bound into the multi-layered, highly cross-linked Gram-positive cell wall thus staining the cells purple.

The decolorization step must be performed carefully. Otherwise over-decolorization may occur. This step is critical and must be timed correctly otherwise the CV stain will be removed from the Gram-positive cells. If the decolorizing agent is applied on the cell for too long time, the Gram-positive organisms to appear Gram-negative. Under-decolorization occurs when the alcohol is not left on long enough to wash out the CV-I complex from the Gram-negative cells, resulting in Gram-negative bacteria to appear Gram-positive.

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3 years ago