Biological membranes are present in all cells, and in eukaryotic cells they also form the endomembrane system. They act as gatekeepers that selectively move certain ions and compounds into and out of the cell or cell organelles. Which statement best describes a biological membrane? a bilayer containing lipids with hydrophilic head groups facing inward and hydrophobic tail groups extending toward the extracellular fluid and cytoplasm a bilayer containing lipids with hydrophobic head groups facing the extracellular fluid and cytoplasm, and hydrophilic tail groups extending inward a bilayer containing lipids with hydrophilic head groups facing the extracellular fluid and cytoplasm, and hydrophobic tail groups extending inward Which biomolecules are components of biological membranes? nucleic acids proteins lipids How is the biological membrane bilayer held together? crosslinks noncovalent interactions peptide bonds covalent bonds

A bilayer containing lipids with hydrophilic head groups facing the extracellular fluid and cytoplasm, and hydrophobic tail groups extending inward.

Proteins and Lipids

The biological membrane bilayer is held together by non covalent interactions.

Explanation:

The structure of the biological membrane is such that the major components found in this membranes are phospholipids although other components are present including various proteins, glycolipids etc. These phospholipids forms a bilayer (two layer) and each phospholipid has an hydrophilic head group (which is attracted to the fluidic environment both extracellular and cytosolic environment) and a hydrophobic tail (which is insolube in both environment). the arrangement is such that the hydrophilic heads of both bilayer that love water faces these two envirionments while the hydrophobic tails of both layers extend towards each other.

The biological membrane bilayer is held together by non covalent bonds. the proteins and lipid molecules in the bilayer are held together by this non covalent bonds including van der waals forces which also holds the hydrophobic tails together. the hydrogen bonds bind the hydrophilic heads with water allowing for the stabilization of the structure.

the corpus luteum secretes estrogens and progesterone. the latter hormone causes changes in the uterus that make it more suitable for implantation of the fertilized ovum and the nourishment of the embryo. if the egg is not fertilized, the corpus luteum becomes inactive after 10–14 days, and menstruation occurs.

i hope this : )