STD 12 - 7. human health and disease — NEET STD 11 Science — Question

Zoological name of common Indian Krait is

Select the correct statement for outbreeding devices
A. In some species, pollen release and stigma receptivity are not synchronised.
B. In some species, the anther and stigma are placed at different positions so that the pollen can not come in contact with the stigma of the same flower.
C. Continued cross-pollination result in inbreeding depression.
D. In dioecious plant only autogamy prevents.

Skeletal system consists of a framework of bones and a few cartilages. Bone and cartilage are specialised connective tissues. From given statement which of the following are correct for human skeletal system ?
(i) In human beings, this system is made up of 206 bones and a few cartilages.
(ii) Axial skeleton comprises 80 bones distributed along the main axis of the body.
(iii) The skull, vertebral column, sternum and ribs constitute axial skeleton.
(iv) Cranial bones are 8 in number. The facial region is made up of 14 skeletal elements which form the front part of the skull.
(v) First vertebra is the atlas and it articulates with the occipital condyles and human skull is bicephalic.
(vi) The number of cervical vertebrae are seven in almost all mammals including human beings.
(vii) Ribs has two articulation surfaces on its dorsal end and is hence called dicondylic.
(viii) Last 3 pairs of ribs are not connected ventrally and are therefore, called floating ribs.

Which of the following dominated in palaeozoic era

Normal activities of the heart are regulated intrinsically, i.e., auto regulated by specialised muscles (nodal tissue), hence the heart is called myogenic. Read following statement and choose correct option for right statements ?
(i) Mass of this tissue is seen in the lower left corner of the right atrium close to the atrio-ventricular septum called the sino-atrial node (SAN).
(ii) A bundle of nodal fibres, atrioventricular bundle (AV bundle) continues from the AVN which passes through the atrio ventricular septum is known as bundle of His.
(iii) Bundle of His immediately divides into a right and left bundle which form Purkinje fibres.
(iv) The nodal musculature has the ability to generate action potentials without any external stimuli, i.e., it is autoexcitable.
(v) The SAN can generate the maximum number of action potentials, i.e., 90-95 min.
(vi) Our heart normally beats 70-75 times in a minute (average 72 beats min).

The principal nitrogenous excretory compound in humans is synthesised

Assertion: The Malpighian corpuscle, PCT and DCT of the nephron are situated in the cortical region of the kidney.
Reason: In cortical nephrons, the loop of Henle is very long and runs deep into the medulla.

Internal surface of large intestine is