Which of the following is the correct sequence that describes the excitation and contraction of a skeletal muscle fiber?

A. Tropomyosin shifts and unblocks the cross-bridge binding sites.

B. Calcium is released and binds to the troponin complex.

C. Transverse tubules depolarize the sarcoplasmic reticulum.

D. The thin filaments are ratcheted across the thick filaments by the heads of the myosin molecules using energy from ATP.

E. An action potential in a motor neuron causes the axon to release acetylcholine, which depolarizes the muscle cell membrane.

#Question id: 29104

#Unit 8. Inheritance Biology

#Question id: 29105

#Unit 8. Inheritance Biology

If two set of chromosome is considered in G1 phase, then at which phase of the cell cycle, the no of chromosome as well as no of DNA cell both are doubled?

#Question id: 29106

#Unit 8. Inheritance Biology

For the proper segregation of the chromosome at anaphase-I chiasma formation take place. At which stage of the cell cycle crossing over takes place?

#Question id: 29107

#Unit 8. Inheritance Biology

Aneuploids may arise through nondisjunction, the failure of homologous chromosomes or sister chromatids to separate in meiosis. which of the following statements is correct?

a) Meiosis I non-disjunction leads to produce all gamete become aneuploidy

b) Meiosis II non-disjunction leads to produce half of gametes n+1 and n-1 while other half normal haploid

c) Either meiosis I or meiosis II non-disjunction leads to produce all aneuploidy gamete

d) Meiosis II non-disjunction leads to produce all gamete become n+1 and n-1

#Question id: 29108

#Unit 8. Inheritance Biology

If 3 genes are unlinked which is X, Y and Z, the probability of progeny being X+ X-Y+Y- Z- Z- from a cross between  X+X+Y+Y-Z+Z- and X-X-Y+Y+Z-Z- parents will be____

#Question id: 29109

#Unit 8. Inheritance Biology