The uterine lining, or endometrium, is the internal layer of the uterus which thickens and gets filled with blood vessels in preparation to receive a fertilized egg. If this does not happen, the uterus removes this extra layer through the vagina, in a process called menstrual flow, which lasts 5 days average.
Fossil record- species evolve differently in different environments . different species evolve similarly in the same type of environment
homologous structures of living organisms- 2 variations; similar body structures that don't necessarily have similar functions
homologous- diff mature forms but develop from embryonic tissues
vestigial- similar structures with reduced size and lesser or no functions
embryology- early stages of many animals are very similar- suggesting that organisms share common ancestry
<u>Answer</u>: Ionic bond
<u>Explanation</u>:
- An ionic bond is a type of a chemical bond formed by the complete transfer of electrons from one atom to another atom i.e one of the atoms loses its electrons and the other gains it. This results in the formation of 2 oppositely charged ions.
- In sodium chloride, sodium loses one electron from its outermost shell (valence shell) whereas chloride gains it. Due to this sodium gains, a net positive charge and chloride gain a net negative charge.
- So, due to the complete transfer of electrons that takes place from sodium to chloride, the compound generated (Sodium chloride) has an ionic bond.