Doctors use stethoscope to hear the sounds produced during each cardiac cycle. The second sound is heard when
AB valves open up
Ventricular walls vibrate due to gushing in of blood from atria
Semilunar valves close down after the blood flows into vessels from ventricles
Semilunar valves close down after the blood flows into vessels from ventricles
C.
Semilunar valves close down after the blood flows into vessels from ventricles
In healthy adults, there are two normal heart sounds often described as lubb and dup. These are the first heart sound and second heart sound produced by closing of the AV valves and semilunar valves respectively.
Cellular organelles with membranes are
nuclei, ribosomes and mitochondria
chromosomes, ribosomes and endoplasmic
endoplasmic reticulum, ribosomes and nuclei
endoplasmic reticulum, ribosomes and nuclei
Which of the following are most suitable indicators of SO2 pollution in the environment?
Lichens
Conifers
Algae
Algae
A protoplast is a cell
without plasma membrane
without nucleus
undergoing division
undergoing division
A gene showing codominance has:
One allele dominant on the other
alleles tightly linked on the same chromosome
alleles that are recessive to each other
alleles that are recessive to each other
Select the wrong statement:
the viroids were discovered by D.J. Ivanowski
W.M. Stanley showed that viruses could be crystallized
The term 'contagium vivum fluidum' was conined by M.W. Beijerinek
The term 'contagium vivum fluidum' was conined by M.W. Beijerinek
The species confined lo a particular Region and not found elsewhere is termed as
Keystone
Alien
Endemic
Endemic
In human females, meiosis-II is not completed until?
puberty
fertilization
uterine implantation
uterine implantation
