By squeezing a bulb attached to the wide end of the pipette.
Solution:
In children, it is easily found it can cause rickets. Rickets is a rare disease that causes the bones to become soft and bend. In adults, severe vitamin D deficiency leads to osteomalacia. Osteomalacia causes weak bones, bone pain, and muscle weakness.
It happens due to the lack of Calcium.
Producers generally require sunlight to make energy. Since there isn't sunlight at the bottom of the lake, they are unable to photosynthesize and produce energy they need to survive.
