Home/Class 11/Biology/

Question and Answer

Read the assertion and reason carefully to mark the correct option out of the options given below:
(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion
(b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion
(c) If the assertion is true but the reason is false
(d) If both the assertion and reason are false
(e) If the assertion is false but reason is true
Assertion : An artifical pacemaker can replace the sinoatrial node of heart.
Reason : This is because, an artifical pacemaker is capable of stimulating the heart electrically to maintain its beats.

Answer

Answer: A
An artificial pacemaker is a therapeutic instrument which is implanted in the heart of patients to generate the heart beat. A pacemaker is used when the normal heart rate of 72-80 drops down to abnormally low levels like 30-40 due to diseases or operations and threatens the life of the patient. Sometime the SA node may become damaged or defective. if then fails to generate cardiac impulses at the normal rate. the heart beats become abnormally slow and irregular and venticles fail to pump the required amount of blood. this is remedied by the chest of the patient. the artificial pacemaker stimulates the heart electrically at regular intervals to maintain its beats. thus it replaces th SA node as the originator of the cardiac impulse.
To Keep Reading This Answer, Download the App
4.6
star pngstar pngstar pngstar pngstar png
Review from Google Play
To Keep Reading This Answer, Download the App
4.6
star pngstar pngstar pngstar pngstar png
Review from Google Play
Correct46
Incorrect0
Watch More Related Solutions
Read the assertion and reason carefully to mark the correct option out of the options given below:
(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion
(b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion
(c) If the assertion is true but the reason is false
(d) If both the assertion and reason are false
(e) If the assertion is false but reason is true
Assertion : Electorcardiogram is record of electrical activity of the heart which shows certain waves called \({P},{Q},{R},{S}\) and \({T}\) waves.
Reason : It gives important information concerning the spread of excitation to the different parts of heart and it is of value in the diagnosis of cases of abnormal cardiac rhythm and myocadial damage.
Who is know as father of physiological genetics or father of biochemical genetics
(A) Slatyper
(B) Charles Elton
(C) Taylors
(D) Archibald Garrod
Vinegar is produced from sugars with the help of
Or
In the formation of ascorbic acid, the micro-organisme
(A) Lactobacillus
(B) Acetobacter
(C) Nitrosomonas
(D) Salmonella
In India coniferous forests are found in:
(A) Madhya Pradesh
(B) Himalaan region
(C) Satpura hills
(D) Rajathan
Solve that following equations :
\(\text{tantheta}+\text{tan}{\left(\theta+\frac{\pi}{{3}}\right)}+\text{tan}{\left(\theta+\frac{{{2}\pi}}{{3}}\right)}={3}\)
What is meant by the term "coordination number"?
b. What is the coordination number of atoms:
i. in a cubic-packed structure?
ii. In a body-centreds structure?
Obtain the first Bohr radius and the ground state energy of a muonic hydrogen atom (i.e., an atom in which a negatively charged muon \({\left(\mu\right)}\) of mass about \({207}{m}_{{e}}\) revolves around a proton).
Obtain approx. the ratio of the nuclear radii of the gold isotope \(._{{79}}{A}{u}^{{{197}}}\) and silver isotope \(._{{47}}{A}{{g}^{{{107}}}}\).
(i) If \({f}=+{0.5}{m}\), what is the power of the lens ?
(ii) The radii of curvature of the faces of a double convex lens are \({9}{c}{m}{\quad\text{and}\quad}{15}{c}{m}\). Its focal length is \({12}{c}{m}\). What is the refractive index of glass ?
(iii) A convex lens has \({20}{c}{m}\) focal length in air. What is the focal length in water ? (Refractive index of air-water \(={1.33}\), refractive index of air-glass \(={1.5}\)).
A 25 watt bulb emits monochromatic yellow light of wavelength of \({0}.{57}\mu\) m. Calculate the rate of emission of quanta per second .

Load More