Which hormone prevents degeneration of the corpus luteum?

hCG

Explanation:

The corpus luteum also called "yellow body" is the remaining of the ovarian follicle that has released a mature egg during a previous ovulation (it develops at each menstrual cycle). The corpus luteum is an endocrine structure which produces  of progesterone, estradiol and inhibin A.

If egg released during the ovulation becomes fertilized, human chorionic gonadotropin (hCG) secreted by the cells of the blastocyst signals the corpus luteum to continue progesterone secretion.The role of the corpus luteum is  to maintain endometrium of the uterus and provide an area rich in blood vessels for the zygote's development.

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