The systole represents the contraction of both left and right ventricles and pumps the blood to the body and the right ventricle to the lungs. This involves the opening and closing of the valves. The closing of the atrioventricular valves produces lub sound.

At the end of the systole or ventricular contraction or when the blood has been pumped to the aorta and the pulmonary valves then the semilunar valves present in the aorta and pulmonary closes. This produces a sound dub.

Therefore,lub dub is associated with the physical contraction of the heart but not the turbulence of the blood.

Thus, the selected option is the correct answer.

7 0

3 years ago

Do open oceans have unlimited nitrogen, rich in silica and iron, or are nutrient-poor environments

Gre4nikov [31]

Open oceans are nutrient poor environments rather than having plentiful resources.

5 0

3 years ago

Antimicrobial susceptibility testing was performed to screen a novel compound. The MIC was found to be 10ng/mL. Use the followin

Alinara [238K]

Answer:

a) Percent recovery

100%, 70.58%, 4.11%, 1.29% , 0%

b) MBC = 160 ng mL

c) Static

Explanation:

A) Calculate the percent recovery for each group

i) for 0ng mL

( 3.4*10^5 / 3.4*10^5 ) * 100 = 100%

ii) for 10ng mL

( (2.4 * 10^5) / (3.4 * 10^5) ) * 100 = 70.58%

iii) for 20ng mL

( ( 6.4 * 10^5 ) / ( 3.4 * 10^5 ) ) * 100 = Nil

iv) for 40 ng mL

( ( 1.4 * 10^4 ) / ( 3.4 * 10^5 ) ) * 100 = 4.11 %

v) for 80 ng mL

( ( 4.4 * 10^3 ) / ( 3.4 * 10^5 ) ) * 100 = 1.29%

vi) for 160 n mL

percentage recovery = 0%

B) what is the MBC

The value of MBC = 160 n mL because at this concentration CFU/mL = 0

c) determine if the antimicrobial tested is static or cidal

condition : If, the ratio of MBC : MIC is ≤4 then novel compound is Cidal

MBC / MIC = 160ng / 10ng = 16 : 1

hence we can conclude that the antimicrobial tested is STATIC

7 0

3 years ago