In order to maintain homeostasis, cells must be able to i. move from place to place ii. extract energy from food iii. regenerate if they burst iv. get rid of waste a. i and ii only b. ii and iv only c. i, ii, and iv only d. ii, iii, and iv only

B. II and IV only

Explanation:

Homeostasis is the maintenance of the internal environment with respect to the external environment. Therefore, locomotion and regeneration are not the criteria for homeostasis. The most important criteria of homeostasis are how a cell can maintain its energy demands as well as get rid of wastes to do metabolic functioning. If a cell cannot get energy from food, it can not survive. Likewise, if a cell cannot get rid of its waste, it will pile up inside and cause cell toxicity.  

stridor can't collapse a lung.

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.