A paramecium is a single-celled, freshwater protist that lacks a cell wall but contains a contractile vacuole. The contractile vacuole is surrounded by rings of proteins that can contract when the vacuole is filled with water, expelling the water from the paramecium. What would happen to a paramecium placed into a freshwater aquarium that has been treated with a chemical that disrupts the function of the contractile vacuole?

economic impact of malaria is estimated to cost africa $12 billion every year. this figure factors in costs of health care, absenteeism, days lost in education, decreased productivity due to brain damage from cerebral malaria, and loss of investment and tourism.

answer : haversian

[explanation: -(compact bone is organized as parallel columns, known as haversian systems, which run lengthwise down the axis of long bones. these columns are composed of lamellae, concentric rings of bone, surrounding a central channel, or haversian canal, that contains the nerves, blood vessels, and lymphatic system of the bone)]