STD 11 - 4. Animal kingdom — NEET STD 11 Science — Question

Colour blindness results from

In most mammals, the testes are located in scrotal sac for

Which one of the following items gives its correct total number?

The drugs used by weight conscious peoples to reduce appetite and increase alertness are

Choose correct sequence of mechanism of vision
(i) The light rays in visible wavelength focused on the retina through the cornea and lens
(ii) Light induces dissociation of the retinal from opsin resulting in changes in the structure of the opsin
(iii) This causes membrane permeability changes.
(iv) Potential differences are generated in the photoreceptor cells rods and cones
(v) This produces a signal that generates action potentials in the ganglion cells through the bipolar cells.
(vi) These action potentials (impulses) are transmitted by the optic nerves to the visual cortex area of the brain.
(vii) Where the neural impulses are analysed and the image formed on the retina is recognised based on earlier memory and experience.

Nicotine is

What is correct for pills ?

Which of the following statements are correct for transport of carbon dioxide ?
(i) Nearly 20-25 per cent of CO₂ is transported by RBCs as carbamino-haemoglobin.
(ii) 70 percent CO₂ is carried as bicarbonate.
(iii) About 7 per cent of CO₂ is carried in a dissolved state through plasma.
(iv) Binding of carbon dioxide with haemoglobin is related to the partial pressure of CO₂
(v) pO₂ is a major factor which could affect binding of carbon dioxide with haemoglobin.
(vi) When pCO₂ is low and pO₂ is high as in the tissues, more binding of carbon dioxide occurs whereas.
(vii) When the pCO₂ is high and pO₂ is low as in the alveoli, dissociation of CO₂ from carbamino- haemoglobin takes place.
(viii) Every 100 ml of deoxygenated blood delivers approximately 4 ml of CO₂ to the alveoli.

The classical example of adaptive radiation in development of new species is