Answer:
A person can have normal chromosomes in number and structure, but still have a disease or condition caused by a mutation in one or more of the genes on the chromosomes. A single gene defect usually does not cause the chromosome structure or number to be abnormal.
Explanation:
I'm not sure if this is correct but hope it helps.
Answer:
a. methylation at lysine 9 or 27 of histone H3.
Explanation:
Methylation causes the switching off of genes using steric hinderance to prevent access to DNA.
Prokaryotes- lack a cell nucleus, unicellular, in the bacteria and archaea domain, lack mitochondria and chloroplast, microscopic
eukaryotes- contains a cell nucleus, multicellular, only in the eukarya domain, contains mitochondria and chloroplast, not microscopic
Answer:
Neurons have stable, relatively unchanging internal environments.
Explanation:
Neurons or nerve cells is the structural and functional unit of the nervous system. Neurons consists of the dendrites, axon, cell body and different cell organelles.
The neurons have mitochondria that meets the high ATP requirement and and consume more oxygen. The network of rough endoplasmic reticulum and ribosomes produce large number of proteins in neuron. The internal environment is never stable and gets changed as the nerve impulse transmission occur through the neuron. The membrane potential of the neuron gets changed and changes its internal environment.
Thus, the correct answer is option (B).
