Scientists have discovered a mutation in female drosophila flies that results in infertility. the mutation causes phosphorylation of an amino acid in histones, preventing the histones from binding to dna during cell division. histones are proteins that exist in the nucleus and that package dna into organized units.

explain how this mutation would most likely affect a drosophila fly’s cells during mitosis and meiosis.
explain how phosphorylation of an amino acid could affect chromosomes and cell division, based on how dna, histones, and chromosomes are related.

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).