The ability of an animal to maintain a stable internal environment is called homeostasis.
Sexual reproduction is a process involving the fusion of two gametes to
Gametes are special reproductive cells produced by meiosis. It produces genetically dissimilar offspring. Offspring may inherit beneficial qualities from both parents and there is a greater genetic variation in the offspring, leading to species that are better adapted to changes in the environment.
<span>A tiger looks so much different as an adult than it did as a single fertilized egg because it developed through different stages from being a zygote (fertilized egg), to becoming an embryo (where it experiences intense cellular changes), to becoming a fetus (where it gains a great measure of cell specialization, and develops distinct tissues and organ systems). After birth, the tiger still undergoes further growth and development into adulthood. This is largely regulated by the expression of different genes at different times and also by environmental factors.</span>
