In an antarctic ecosystem, phytoplankton are eaten by krill, which are eaten by baleen whales. if the population of phytoplankton suddenly decreased: the population of whales would increase. the population of whales would decrease. the population of krill would increase. none of the above.

The population of whales would decrease.

Explanation:

Organisms feed on one another in their name environment in order to obtain energy needed for their life processes. The habitat described here is aquatic, and it involves a series of organisms involved I feeding pattern called FOOD CHAIN. Every food chain starts with an autotroph i.e. an organism that is capable of making Its own food by trapping light energy from the sun.

This autotophs are called PRODUCERS. The producer in this case are PHYTOPLANKTONS, which starts the food chain. If the population of the producer (phytoplanktons) decrease, there will be a reduction in the number of consumers at each trophic level i.e. the number of krills and whales will also decrease because only a producer is capable of starting a food chain.

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.

several tissues working together form an organ, and several organs together make up an organisms.

the group of cell that carries out special jobs are tissue.