Protons have a positive charge. The number of protons in a nucleus determines the identity of the atom (element) and this number is called the atomic number.
D. Proton
The genotype of a normal male zygote is XY, with the X chromosome (sex chromosome) coming from the mother and Y from the father.
Chlamydia is a disease transmitted by sex with someone infected. Its caused by bacteria and often is asymptomatic.
Treatment is with antibiotics, and it's essential to know if one is infected because in women can cause infertility, and in males can cause urethra complications like inflammation and obstruction.
Large central vacuoles, chloroplasts, and cell walls are only found in plant cells.
Large central vacuoles store nutrients and waste products, but they also maintain the plants' structures.
Cell walls also maintain structure and rigidity.
Chloroplasts are used in the process of photosynthesis, which only occurs in plants.
