A baby receives half of its genes from the mother and half from the father when the sperm and egg join to make a fertilized egg, or zygote. Identical twins form when a fertilized egg splits into two separate life forms. Using what you
learned in the video, draw a model that shows clearly how cell division forms identical twins.

acid rain does not usually kill trees directly. instead, it is more likely to weaken the trees by damaging their leaves, limiting the nutrients available to them, or poisoning them with toxic substances slowly released from the soil. the main atmospheric pollutants that affect trees are nitrates and sulphates.

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.