In four o'clock flowers, red petals show incomplete dominance over white petals. If two pink flowers are crossed, 50 percent of the flowers will be homozygous, and 25 percent of the flowers will be heterozygous.
Melanin provides pigmentation to the skin and it also provides UV ray protection (which is its role in the epidermis).
Answer and explanation;
Nucleus; houses a cell's DNA and its processes include protein, replication and packaging for cell division. It is also the site for transcription.
Cytosol; coordinates a responsible to the environment, metabolism and motor proteins.
Endomembrane system; includes the nuclear envelope (surrounds nucleus), rough and smooth ER, golgi body, lysosomes?vacuoles, peroxisome and plasma membrane.
Semiautonomous organelles; mitochondria (animals) and chloroplast (plants) which provide energy for the cell.