Help please! Which is the correct biochemical sequence in the pathway for synthesis of the amino acid arginine?

a) ornithine is converted to arginine, which is then converted to citrulline

b-) citrulline is converted to arginine, which is then converted to ornithine

c-) arginine is converted to citrulline, which is then converted to ornithine

d-) ornithine is converted to citrulline, which is then converted to arginine

Suppose you have monohybrid pea plants in your garden and find that they produce round seed to wrinkled seeds in the ratio of 3: 1. if the allele are designated (r & r) receptively. what is the probable genotypes of the round seeds which produced f 1 ? rr & rr rr only rr & rr rr only rr only

Describe the function of the endomembrane system? what organelles are involved?

Choose the incorrect statement (a) the motor end plate membrane is only capable of generating graded potentials, but it is contiguous with the skeletal muscle sarcolemma, which can generate action potentials. (b) propagation of an action potential through the t-tubules into the sarcoplasmic reticulum triggers the release of ca++ into the cytoplasm of a skeletal muscle fiber. (c) the generation of suprathreshold endplate potentials in multiple muscle fibers could be due to the increased frequency of action potential generation at the axon hillock of a single motor neuron. (d) a greater amount of ach would be found in the presynaptic vesicles of a motor unit that fired several action potentials after exposure to botulinum toxin, than in a motor unit that fired several action potentials after exposure to the venom of the krait snake (which contains α-bungarotoxin).