4. Which of these is not an example of a pure substance?

Why do resistant bacteria multiply faster after a patient has taken antibiotics compared to a healthy person who has not taken a

Alenkasestr [34]

Answer:

When patient takes in antibiotics the resistance bacteria gets a competitive survival advantage over the normal sensitive bacteria and hence grows faster.

Explanation:

Bacteria can acquire resistance by taking in plasmids containing MDR (Multi-Drug Resistance) gene cassettes. The MDR genes produces proteins that can:

Render the antibiotic ineffective to act on its target by inducing chemical modifications on the drug.
Promote efflux of the drug from the bacterial cell so that the drug cannot act upon its target.

When a healthy person ( having no prior exposure to the antibiotic) is infected by bacteria ( both sensitive and resistant varieties):

A competition develops for the host cells and nutrients between the sensitive and the resistant variety.
This mutual competition restricts either of the sensitive or resistant bacterial strain to grow profusely.

When a person (having prior antibiotic exposure), gets infected by bacteria ( both sensitive and resistant varieties) and is exposed to the same antibiotic:

The sensitive variety, due to its sensitivity towards the drug, gets killed.
The resistant variety, due to its MDR genes, bypasses the lethal effect of the drug and survives.
These surviving resistant bacteria can now infect all the available host cells and utilise all the available nutrients without facing any competition and multiply rapidly.

4 0

3 years ago

Drosophila eye color is an X-linked trait. Red eye color is dominant, and white eye color is recessive. Which Punnett square sho

Ira Lisetskai [31]

Answer:

Second Punnett on the first attachment.

Explanation:

In a 4 x 4 Punnett there are a total of 4 squares. Twenty five percent (25%) of 4 is 1. This means that only 1 square out of the 4 should have the genotype that you are looking for.

Okay going at it in a biological sense. Because red eyes is dominant, we know that the allele should be represented by a capital R. It is X-linked, so it should be on the X. The problem is looking for the probability of a male offspring so the combination should be XY (this means the offspring is male, XX is for females).

So taking that all together, you're looking for the genotype combination:

$X^{R}Y$

So you need to find the Punnett that has only 1 square with this combination. The attachment shows which specific Punnett:

6 0

3 years ago

cancerous growths are clonal in origin because cancer cells . multiple choice question. can invade healthy tissues originate fro

rodikova [14]

Cancerous growths are clonal in origin because of cancer cells originate from a single cell that has accumulated genetic changes during cell division.

The human body contains several billion cells. Cells are the teeny, tiny building blocks of our tissues and organs. Every one of us was once a single cell. That cell divided into two new cells after internal replication.

Cells become abnormal when the DNA, which holds the instructions needed for cells to operate, is damaged. The cells they make after that will not be similar to healthy ones. Along with having a variety of appearances, they might also possess different traits. The medical word for this kind of abnormal cell proliferation in body tissue, including skin, is dysplasia. As long as there aren't many abnormal cells and our immune system controls them, we won't get sick from them.

Sometimes these cells can vanish on their own. Only when these cells continue to change and start to divide erratically, leading to lumps or growths, does one of the more than 200 diseases recognized as cancer become apparent. These kinds of growths are tumors.

The complete question is:

Cancerous growths are clonal in origin because of cancer cells __________.

multiple choice questions.

(A). can invade healthy tissues originating from a single cell that has accumulated genetic changes during cell division

(B) can migrate to other areas of the body and form secondary tumors at the new sites

(C) can form a tumor that is localized only at one site

To learn more about cancer please click on the given link: brainly.com/question/14336972

#SPJ4

3 0

1 year ago

Which relationship between the two species listed would be mutually beneficial?

Andrei [34K]

C. flower plant and a bee

5 0

3 years ago

Sometimes we call "clean energy"<br> *<br> A) Fossil fuels B) Petroleum C) green energy

m_a_m_a [10]

Answer:
C) Green energy

7 0

3 years ago