Moraines are made of till. They form when a glacier stays in one place for a long time and deposits a pile of till, then it retreats and leaves a moraine.
Answer:
Spindle fibers form a protein structure that divides the genetic material in a cell. The spindle is necessary to equally divide the chromosomes in a parental cell into two daughter cells during both types of nuclear division: mitosis and meiosis. During mitosis, the spindle fibers are called the mitotic spindle.
Explanation:
Answer:
b. They are produced by memory B cells
Explanation:
The rapid cell division in activated B cells is followed by the differentiation of daughter cells into the plasma cells. The plasma cells are the precursor for antibodies and memory B cells. The antibodies kill the antigens while memory B cells are long-lived cells.
Hence, antibodies are not produced by memory B cells but by plasma cells.
Plants' stomata refers to the small pores that are found on plants' tissues and leaves. They possess the ability to open and close and thus they regulate water and gases exchange in plants. Green plants have the ability to produce their own food by using the energy from the sun;the process is called photosynthesis. During the day, when there is sunshine, the plants' stomata are always open in order to trap energy from the sun for photosynthesis. The stomata also allow carbon dioxide and oxygen gases to diffuse in and out of the leaves' cells. The stomata usually closes at night in order to prevent excessive water loss.
