Question

no explaination is needed

21. Iodine deficiency promotes the formation of enlarged thyroid glands (goitre) because a) more thyroid hormones are now produced in the thyroid gland. b) the thyroid gland switches to production of a different hormone. e) reduced levels of thyroid hormones fail to prevent stimulation of thyroid gland by TRH and TSH. d) iodine now needs to be synthesized in the thyroid gland. 22. An unequal distribution of ions inside and outside of a nerve cell is essential for generating its resting membrane potential. At rest there is a) a higher concentration of K inside the cell. b) a higher concentration of K outside the cell. e) a higher concentration of Na inside the cell. d) a higher concentration of CT inside the cell. 23. In nerve cells the stimulus amplitude is encoded a) in the size (amplitude) of the action potential. b) in the frequency of action potentials. e) in the duration of the action potential. d) in the resting membrane potential. 24. During muscle contraction a) actin and mysoin filaments slide past each other. b) actin filaments become shorter. c) myosin filaments become shorter, d) actin and myosin filaments fold. 25. The sympathetic division of the autonomic nervous system a) prepares the body for action ("fight or flight"). b) promotes digestion and self-maintenance ("rest or digest") c) controls voluntary movements d) relays sensory information from the intemal organs. 26. Which of the following statements is NOT true? a) Variation in the vertebrate limb is a result of heterochrony b) Similarity in vertebrate limbs is an example of homology c) Heterochrony does not affect the timing of expression of developmental genes! d) Heterochrony can lead to paedomorphosis. 27. The similarities between sugar gliders and flying squirrels are due to a) paedomorphosis. b) heterochrony c) convergent evolution d) polyploidy

Answer 1

Ans -1 More thyroid Hormone are now powduced in the thysoid grand day Higher conc. of K+ inside the cell. 23) 6 Fuelquency of action potential 24) as Actin myo sín filament Slide Past ovey each other 95) ay porepare the body for action