The plasma membrane needs lipids, which make a semi-permeable barrier between the cell and its environment. It also needs proteins, which are involved in cross-membrane transport and cell communication, and carbohydrates, which decorate both the proteins and lipids and help cells recognize each other. Hope this helps :)
The answer is B) Genetic variation
Answer; All the above
A) an atom seeks to fill its outer shell of electrons
B) an atom seeks to balance its positive and negative charges
C) the reaction will result in paired electrons
Explanation;
-In a chemical reaction, reactants contact each other, bonds between atoms in the reactants are broken, and atoms rearrange and form new bonds to make the products.
-During a chemical reaction an atom may lose of gain electrons resulting positive and negative ions (ionic bond formation) or may result to the paired electrons (sharing of electrons).
The horse and donkey, though closely related by sharing a common ancestor, are different species. They have different number of chromosomes hence pairing of homologous chromosomes during fusion of gametes becomes complicated. The mule will have an extra chromosome from the horse hence will have abnormalities such as sterility. A Mule is unable to reproduce due to this same phenomenon. Homologous chromosomes are not well paired for meiosis I.
4.6 billion years ago
The study pushes back the clock on the origin of Earth's water by hundreds of millions of years, to around 4.6 billion years ago, when all the worlds of the inner solar system were still forming. Scientists had suspected that our planet formed dry, with high-energy impacts creating a molten surface on the infant Earth.
i hope this helped, have a nice day! (o:
