The action or process of fertilizing an egg, female animal, or plant, involving the fusion of male and female gametes to form a zygote. The gametes that participate in fertilisation of plants are the sperm (male), and the egg cell, and in flowering plants a second fertilisation event involves another sperm cell and the central cell which is a second female gamete. In flowering plants there are two sperm from each pollen grain.
Biology is the study of life, and uses the scientific method, the basis of science, to do so. Hypotheses are made, tested, and remade, until a theory is made, which then becomes Scientific law.
<span>On the left, they drain into the renal vein
which in turn drains into the inferior vena cava. By contrast, all the
lumbar veins and hepatic veins usually drain directly into the inferior vena cava.</span>
Biotic factors of an ecosystem are all the living organisms that affect other organisms in an ecosystem and include animals, plants, microorganisms, dead organisms, and even animal waste. Example of biotic factors include: Grass as producers (autotrophs).