STD 11 - 19. Chemical coordination and integration — NEET STD 11 Science — Question

Which one of the following groups of animals is correctly matched with its characteristic feature without any exception?

Damage to thymus in a child may lead to

Assertion: Nicotine stimulates adrenal gland to release adrenaline and noradrenaline into blood circulation.
Reason: Both of which raise blood pressure and heart rate.

Which of the following statements are correct ?
(i) Each seminiferous tubule is lined on its inside by two types of cells called male germ cells and Sertoli cells.
(ii) Sertoli cells undergo meiotic divisions and provide nutrition to the germ cells.
(iii) The regions outside the seminiferous tubules called interstitial spaces, contain interstitial cells for secretion of inhibin.
(iv) Leydig cells synthesise and secrete testicular hormones called androgens.
(v) The male sex accessory ducts include epididymis and vas deferens.
(vi) The seminiferous tubules of the testis open into the vasa efferentia through rete testis.

Which of the following statements are not correct for disorders of circulatory system ?
(i) If repeated checks of blood pressure of an individual is 140/90 (140 over 90) or higher, it shows hypertension.
(ii) High blood pressure leads to heart diseases and also affects vital organs like brain and kidney.
(iii) Coronary artery disease, often referred to as atherosclerosis, affects the vessels that supply blood to the heart muscle.
(iv) Atherosclerosis is caused by deposits of calcium, fat, cholesterol and fibrous tissues, which makes the lumen of arteries narrower.
(v) Angina or angina pectoris is acute chest pain which appears when no enough oxygen is ching the heart muscle.
(vi) Angina can occur in men and women of any age but it is more common among the middle-aged and elderly.
(vii) Heart failure is same as cardiac arrest or a heart attack.

Most of the sexually transmitted diseases are completely curable if detected early and treated properly, except

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.

A collagenous connective tissue layer hold the muscle bundles together.