Animals have a variety of adaptations, including trachea and gills, which allow this key process to occur. which provides the molecules necessary for cellular respiration and efficient atp synthesis? a. nutrient absorption b. digestion c. waste elimination d. gas exchange

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.

c should be the answer