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3 years ago

Why do water droplets form on the outside of a glass of ice water??

1 answer:

7 0

It is because of condensation. When warm air hits the cold surface, it condenses, leaving droplets of water outside the glass.

Another way of putting it is, when water vapor in the air comes in contact with cold, like ice water, the molecules slow down and get closer together, causing the gaseous water vapor to turn back into liquid water droplets, which is condensation.

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Which is an application of DNA technology in medicine? mapping human genes for manipulation determining specific traits that a b

Marina86 [1]

The answer is determining hereditary diseases in individuals and families

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3 years ago

Read 2 more answers

Which is NOT part of the cell theory?

atroni [7]

Answer:

Explanation: Hope this helps! ^^

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3 years ago

22. A plant geneticist is investigating the inheritance of genes for bitter taste (Su) and explosive rind (e) in watermelon (Cit

mylen [45]

Answer:

See the answer below

Explanation:

Using the formula for calculating Chi square ( $X^2$ ):

$X^2$ = $\frac{(O - E)^2}{E}$ where O = observed frequency and E = expected frequency.

The observed frequencies for the four phenotypes are 88, 62, 62, and 81 respectively.

For the expected frequency, the phenotypes are supposed to assort in 9:3:3:1 according to Mendel ratio.

Hence, expected frequencies are calculated as:

phenotype (1) = 9/16 x 293 = 164.81

phenotype (2) = 3/16 x 293 = 54.94

phenotype (3) = 3/16 x 293 = 54.94

phenotype (4) = 1/16 x 293 = 18.31

The $X^2$ is calculated thus:

Phenotype O E $X^2$

1 88 164.81 $\frac{(88 - 164.81)^2}{164.81}$ = 35.80

2 62 54.94 $\frac{(62 - 54.94)^2}{54.94}$ = 0.91

3 62 54.94 $\frac{(62 - 54.94)^2}{54.94}$ = 0.91

4 81 18.31 $\frac{(81 - 18.31)^2}{18.31}$ = 214.64

Total $X^2$ = 35.80 + 0.91 + 0.91 + 214.64 = 252.26

To the nearest tenth = 252

Degree of freedom = n - 1 = 4- 1 = 3

$X^2$ tabulated = 7.815

The calculated  $X^2$  exceeds the critical value, hence, the null hypothesis is rejected. The two genes did not assort independently. 

4 0

2 years ago

Choose the CORRECT statement concerning the cell membrane lipid molecules

VashaNatasha [74]

Answer:

The correct statement concerning the cell membrane lipid molecules is that "energy is not expended during diffusion" (Option d)

Explanation:

Biological membranes are formed by two lipidic layers arranged with their hydrophilic polar heads facing the exterior and the interior of the cells, and their hydrophobic tails against each other. Membranes are fluid, which means that molecules that form it have the capability to move through it.

Lipids can easily change places with other neighbor lipids by lateral diffusion in the same layer. This is passive diffusion, which means that it does not need energy to happen.

Lipids can also diffuse transversally to the other layer, but this kind of movement is not as easy as lateral diffusion.

There are also other lipidic movements as rotational diffusion that imply the rotation of the molecule.

Through this lipidic bilayer, there is also a passive transport of some particles from one side of the cell to the other which happens because of concentration differences.

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3 years ago

An example of a population in which evolution could

Snezhnost [94]

An example of a population in which evolution could take place in a relatively short period of time could be pathogenic bacteria exposed to antibiotics.

Answer: Option A

Explanation:

Evolution if takes place within a short period of time say the next generation that is called as micro evolution. This is caused when a specific organism exposed in a different environment at once modifies its genes to suit the new environment. This phenomenon can be very well seen in the pathogenic bacteria which are exposed to antibiotics.

When an antibiotic is prescribed to bacteria initially it nullifies its effect by destroying it. When continuously exposed to a certain antibiotic some bacteria dies but there are few which becomes resistant to it and survives. This on the other hand multiplies producing a generation that can’t be touched by the antibiotic.

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3 years ago