Considering that males can have Klinefelter (XXY) syndrome, XYY, and normal XY chromosomal combinations, and females can have Tu
rner (XO) syndrome, poly-X (XXX, XXXX), and normal XX combinations, it is obvious that (A) maleness results from the presence of only one X chromosome
(B) maleness results from the absence of two or more X chromosomes
(C) maleness results from the minimal presence of one Y chromosome
(D) femaleness results from the presence of two or more X chromosomes
(C) maleness results from the minimal presence of one Y chromosome
Explanation:
Human males have one Y and one X chromosome as their sex chromosomes. However, the human males with Klinefelter (XXY) syndrome have two copies of X chromosome as the human males but also have one Y chromosome. Similarly, human females have two X chromosomes as sex chromosomes but the females with Turner (XO) syndrome have only one X chromosome and the females with poly-X (XXX, XXXX) have more than two X chromosomes.
This means that the Y chromosome regulates sex in human beings. If one copy of the functional Y chromosome is present in the cells, the fetus will develop into a male. The absence of a functional Y chromosome will make the fetus develop into a female.
Plasmodesmata are microscopic channels which traverse the cell walls of plant cells and some algal cells, enabling transport and communication between them. This is the path that viruses use to spread throughout a plant's system.
