STD 11 - 15. Body fluids and criculations — NEET STD 11 Science — Question

A pair of external nostrils present in humans opens out

The Permian period, during which the first most modern orders of insects appeared, occurred approximately

Assertion : Mast cells in the human body release excessive amounts of inflammatory chemicals, which cause allergic reactions.

Reason : Allergens in the environment on reaching human body stimulate mast cells in certain individuals.

Mark the given statements True (T) or False (F) :
(i) The neural system provides an organized network of point-to-point connections for quick coordination. The endocrine system provides chemical integration through hormones.
(ii) The PNS includes the brain and spinal cord and is the site of information processing and control.
(iii) The efferent nerve fibres transmit impulses from tissues/organs to the CNS and the afferent fibres transmit regulatory impulses from the CNS to the concerned tissue.
(iv) The PNS is divided into two division called somatic and autonomic neural system.
(v) The autonomic neural system is classified into sympathetic and parasympathetic neural system.
(vi) The axon of neurons contain certain granular bodies called nissl's granules.
(vii) Bipolar type of neurons are found in retina of eye which contain one axon and one dendrite.
(viii) Unmyelinated nerve fibre is enclosed by a Schwann cell that does not form a myelin sheath around the axon.
(ix) The gap between two adjacent myelin sheaths is called nodes of ranvier.
(x) At resting state, axonal membrane is comparatively more permeable to Na⁺ ions and nearly impermeable to K⁺ ions.
(xi) The sodium-potassium pump transport 2Na⁺ outwards and 3K⁺ into the cell.
(xii) The electrical potential difference across the resting plasma membrane is called as the resting potential.
Choose the correct option given below :-

The bread is soft and porous when the yeast cells are mixed in the lump of wheat flour because

Choose the correct one for Hemichordata from given statements.
(i) The body is cylindrical and is composed of an anterior proboscis, a collar and a long trunk.
(ii) Circulatory system is of open type.
(iii) Respiration takes place through gills.
(iv) Excretory organ is proboscis gland.
(v) They are dioecious, fertilisation is external and development is indirect.

Which of the following belongs to Phylum Arthropoda

From the following statements select the worng one

Which of the following is used as 'clotbuster'. For removing clots from blood vessels of patient who have undergone myocardial infartion