The answer is foreign pathogens.
A baby isn't considered a fetus until about 8 to 9 weeks after
conception. During those first weeks, the baby is considered as the
embryo. The embryo is the development of the pregnancy until about 9
weeks, it will then turn into a fetus.
<span>Reptiles and birds excrete waste as an insoluble white solid that is called uric acid. This means that these wastes are made of very little amount of water. This helps them to maintain internal homeostasis in hot climates since the presence of water allows them to cool easily.</span>
Proteins in a protein complex are linked by non - covalent protein - protein interactions. The process of complex formation comprises of steps namely : ... An encounter complex is formed that either proceeds towards final complex or dissociates again.
Meiosis in reproductive organs (testes and ovary) produce gametes. Each human cell including reproductive cells contains 23 pair of chromosomes. Meiosis separates the two chromosomes from each pair thus, each gamete receives only one copy of each chromosome. Therefore, each gamete has 23 new chromosomes, one from each of the 23 pairs. During meiosis, exchange of chromosome segment between copies of a pair of chromosomes. The exchange of chromosome segments creates new combinations of genes which enhances genetic variability within a species.