Crossing-over contributes to the recombination of genetic material in offspring. When does crossing-over happen during meiosis? Group of answer choices

when homologous chromosomes pair and portions of chromatids break off and are exchanged

when the DNA of the diploid cell is copied

when spindle fibers move the chromosomes toward the midline of the dividing cell

when homologous chromosomes move to opposite ends of the dividing cell

doctors i believe if i'm wrong sorry

the level of progesterone is low at the pre-ovulatory phase of the cycle but it gradually increases and the levels are high at the luteal phase. if pregnancy occurs, the level of progesterone will be high throughout the pregnancy.

if egg is fertilized and the mother gets pregnant, progesterone starts preparing the uterus for the implantation. it starts building up the lining of uterus and make it hostile of the period of pregnancy.