Model Paper 1 — NEET STD 11 Science — Question

Production, secretion and ejection of milk requires the synergistic effects of prolactin and

Which of the following is a once-a-week pill with very few side effects and high contraceptive value?

A true breeding plant producing red flowers is crossed with a pure plant producing white flowers. Allele for red colour of flower is dominant. After selfing the plants of first filial generation, the proportion of plants producing red and white flowers in the progeny would be

Which one feature is common to leech, cockroach and scorpion

All of the following are parts of forebrain, except

Which part of Cockroach has both exoskeleton and endoskeleton

If you suspect major deficiency of antibodies in a person, to which of the following would you look for confirmatory evidence ?

Read the following and choose the option with all incorrect statements.
(i) Heart is protected by a double walled membranous bag, pericardium enclosing the pericardial fluid.
(ii) The atrium and the ventricle of same side of heart are separated by thin fibrous tissue called atrio-ventricular septum.
(iii) The opening between the right atrium and the right ventricle is guarded by a valve formed by 3 muscular flaps or cups, the tricuspid valve.
(iv) Bicuspid valve also called mitral valve guard the opening between the left atrium and left ventricle of heart.
(v) The openings of the right and left ventricles into the pulmonary artery and the aorta respectively are provided with semicircular valves.
(vi) A specialized cardiac musculature called nodal tissue is distributed in the heart. A patch of this tissue present in right lower corner of right atrium is called SAN and that present in upper left corner of right atrium is called AVN.
(vii) The SAN can generate the maximum number of action potential, i.c., 70-75 min, and is responsible for initiating and maintaining the rhythmic contractile activity of heart. Therefore it is called the pacemaker.
(viii) The average heart beat per minute is 72.
(ix) The action potential generated by SAN which stimulate atrial diastole, increase the flow of blood into ventricles by about 30%.
(x) During ventricular diastole, the ventricular pressure falls causing the closure of semilunar valves which prevents the backflow of blood into the atria.
(xi) The sequential event in the heart which is cyclically repeated is called cardiac cycle.

Ovulation in mammals is caused by