The calcium ion passes easily through the membrane of one cell but cannot cross the
membrane of a second cell. which part of the plasma membrane allows this substance
to cross?
a.) carbohydrate groups on the membrane allow the ions to cross.
b.) the fatty acid tails of the phospholipids allow the ions to cross.
c.) protein channels in the plasma membrane allow the ions to cross.
d.) phosphate groups of the phospholipid bilayer allow the ions to cross.

the corpus luteum secretes estrogens and progesterone. the latter hormone causes changes in the uterus that make it more suitable for implantation of the fertilized ovum and the nourishment of the embryo. if the egg is not fertilized, the corpus luteum becomes inactive after 10–14 days, and menstruation occurs.

i hope this : )

the energy generated by an individual's metabolism is calculated in met (metabolic equivalent of task). the met is the ratio of the work metabolic rate to the resting metabolic rate. one met is illustrated as 1 kcal per kilogram per hour, and is probably equal to the energy cost of sitting quietly.

1 met is equal to 1.162 watt per kg

1 kg is equal to 1000 grams

as the person weighs 80000 gm, that is, 80 kg.

therefore, 80*1.162 = 92.96

thus, the person expends 92.96 watts of power while at rest.