3. A. They help separate the chromosomes
Spindle fibers attach to chromosomes and pull them towards different poles of the cell during the final phases of mitosis. The result is two identical cells with the same chromosomes.
4. C. A cell plate
A cell plate is a structure found in plant cells on the top and bottom of the cell. It is a perforated wall made of cellulose and it allows for substances to move in and out of the cell, as the outer most layer of a plant cell, the cell wall, is impermeable.
Bones are made up of Calcium Phosphate given by the chemical formula, 
. When bones are kept in Hydrochloric acid, given by the chemical formula, HCl, they become soft because the calcium compound present in the bones changes its form. The following double displacement reaction takes place when the bones are kept in HCl,
---> 
Calcium chloride is water soluble, and gets washed away. This makes the bone thin and soft.
Fertilization takes place in the fallopian tube
Answer:
b. excretes excess albumen molecules
Explanation:
Albumin is a type of globular protein which is present in the blood plasma and it is about 75-78% of the plasma. It is a small protein soluble in water. Its main role is to maintain the oncotic pressure of blood by binding to water fatty acids, cations and hormones. When albumin level falls and no longer sustain sufficient colloid osmotic pressure, then to counterbalance hydrostatic pressure, swelling of body (edema) develops. The urinaray does not excretes excess albumen molecules from the blood.
