Considering that males are produced by Klinefelter (XXY) syndrome, XYY and normal XY chromosome combinations, and females are produced by Turner (XO) syndrome, triple-X (XXX) and normal XX combinations, it is obvious that

a. maleness is caused by the minimal presence of one Y chromosome.
b. maleness occurs in the absence of two or more X chromosomes.
c. maleness is caused by the presence of only one X chromosome.
d. femaleness is caused by the presence of two or more X chromosomes.

The tasmanian devil, a marsupial carnivore, is facing extinction due to devil facial tumor disease (dftd) which causes bulging cancerous lumps and lesions to erupt around the face and neck — often causing enough deformation to make seeing or eating difficult. dftd has evolved into a contagious cancer, a trait that is unique among cancers. devil mating behavior involves biting around the head and neck, allowing cells from one individual — especially cells from the crumbly dftd tumors — to be transferred to the wounds or face of a new individual. this marsupial was once found across australia, but sea levels rose, isolating the tasmanian population, while the australian population went extinct. what would be an outcome of genetic isolation that is likely to have impacted the spread of dftd? a) reduced territory puts diseased individuals in greater contact with non-diseased ones. b) inbreeding results in less variation in facial features so the cancer is generally fatal. c) genetic isolation has made it difficult for scientists to develop a vaccine against dftd. d) the lack of genetic variation in the immune system of tasmanian devils minimizes resistance to the disease.

The chromosomal structure that limits the number of cell divisions of a cell is the the chromosomal structure that limits the number of cell divisions of a cell is the kinetochore telomere histones centromere

What is usually (but not always) related to the metabolic processes of living organisms in its organic form?