Our study partner has drawn four models of membrane-bound vesicles to try to show what a vesicle would look like with water both inside and outside of the membrane. Help him to select the most accurate model.

The answer (Image 1) is attached. Since the options weren't provided, I've attached the image of the options, too.

Explanation:

The plasma membrane is composed of phospholipids, a special form of lipids with a hydrophilic head and hydrophobic tail. According to the fluid mosaic model, the hydrophilic heads are positioned towards the outside where they freely interact with the extracellular matrix and cytosol. Whereas, the hydrophobic tails are positioned towards the inside so they aren't exposed to water.

Liposomes are lipid bases particles used for drug and vector delivery. The picture shows a typical liposome.

In the current case, for water to move both outside and inside, hydrophilic heads should be present inside as well as outside the tails.

a tetrad is the foursome during meiosis made by two homologous chromosomes that have each already replicated into a pair of sister chromatids.

this is true, assuming that the allele is completely recessive and incomplete dominance is not a factor.