Eukaryotic sexual life cycles show tremendous variation. of the following elements, which do all sexual life cycles have in common? i. alternation of generations ii. meiosis iii. fertilization iv. gametes v. spores

II. meiosis

III. fertilization

IV. gametes

Explanation:

Gamete formation and fertilization are the processes performed by all the sexually reproducing organisms. Gametes are the cells that are formed in the male and female sexual organs of these organisms. Formation of gametes occurs by meiosis and therefore, the gametes of a diploid organism are always haploid.

Male and female gametes fuse during the process of fertilization and form the zygote which in turn divide repeatedly to produce an embryo. For instance, sperms and eggs are the male and female gametes that are formed in testes and ovaries of male and female human individuals respectively. The fusion of sperm and egg produces a zygote that finally develops into a young one.  

i think its the first one

interphase

the period of cell growth when the cell synthesizes new molecules and organelles. the cell is not dividing and it constitutes the majority of the time spent in the cell cycle

prophase

changes occur in the nucleus and cytoplasm. the chromatin condenses to form structures (sister chromatids) visible with a light microscope and the mitotic spindle begins to form, but the nucleus is still in tact

prometaphase

the nuclear envelope fragments and the spindle microtubules attach to the kinetochores of the sister chromatids

metaphase

all the cell's duplicated chromosomes are lined up at an imaginary plane equidistant between the poles of the mitotic spindle

anaphase

begins when sister chromatids separate from each other and ending when a complete set of daughter chromosomes arrives at each of the two poles of the cell

telophase

the daughter nuclei form at the two poles of a cell

cytokinesis

the division of a cytoplasm to form two separate daughter cells. usually occurs during telophase during mitosis. this and mitosis make up to mitotic (m) phase of the cell cycle