A hydrogen bond is formed when a positively polarized hydrogen atom in one molecule is attracted to a highly electronegative atom in another molecule. In the example of water molecules, the negatively charged oxygen atom in one water molecule attracts the positively charged hydrogen atom in another water molecule. Oxygen atoms tend to steal electrons away from the hydrogen atoms within molecules. When this occurs within a water molecule, the electron loss creates a hydrogen atom with a partial positive charge, which is then attracted to a negatively charged oxygen atom in another water molecule.
The hydrogen bonds that form between water molecules cause them to stick together. This gives water a high boiling point temperature because a greater degree of heat energy is required to break the intermolecular hydrogen bonds. Many organic substances that are required to sustain life, such as nucleic acids and proteins, contain hydrogen bonds. Although these bonds are weaker than the internal ionic or covalent bonds existing between the atoms within molecules, the accumulated strength of hydrogen bonds within living organisms is highly significant and plays an important role in maintaining stability.
Answer:
Diamonds cam form in the mantle because of the impact of the weight of the overlying rock which bears down on it, in combination with the high temperature of the area where they are formed (about 100 miles beneath the surface). Therefore, the correct answer is option D. The weight of the rocks above the mantle results in high pressure.
Explanation:
because of the impact of the weight of the overlying rock which bears down on it, in combination with the high temperature of the area where they are formed (about 100 miles beneath the surface)
Answer:
Lipid bilayer can be defined as a polar membrane, which composes two layers, made up of lipid molecules. It shows both hydrophobic (due to non-polar tails of lipid molecules) and hydrophilic (due to polar heads of lipid molecules) nature, and hence is known as of amphipathic nature.
Lipid bilayer shows selective permeability as not all molecules can cross the lipid bilayer. It can pass non-polar, small, uncharged molecules due to its hydrophobic core, such as oxygen, water, urea.
On the other hand, polar, large, or charged molecules, such as glucose, amino acids, and ions cannot pass through lipid bilayer. These molecules require transport proteins for their transport, which are embedded in lipid bilayer.
he lipid bilayer has unique properties. They are formed in sheet-like structures that contain both a hydrophilic and a hydrophobic moiety. The membrane is composed of lipids and proteins and sometimes even carbohydrates. There are two different membrane proteins in the lipid bilayer.
Two ways:
1. In prophase I of meiosis the homologous chromosomes synapse and crossing over occurs. This switches sections of two of the sister chromatids so the outer two chromatids have the same mix of alleles as the parents and the inner two chromatids have new combinations of alleles.
2. Meiosis puts only one of each kind of chromosome in the gametes, selecting one of each homologous pair at random. Then when each gamete joins with the gamete from the other parent, there are practically infinite combinations of the alleles possible.
Answer:
Explanation: Plankton. ... Plankton includes plants and animals that float along at the mercy of the sea's tides and currents. Their name comes from the Greek meaning "drifter" or "wanderer." There are two types of plankton: tiny plants--called phytoplankton, and weak-swimming animals--called zooplankton.
