1. the cell membrane is mainly made up of lipids and proteins. it acts as amazing
barrier to the surrounding environment. which of the following
statements about lipids best supports the argument that lipids
protect the contents of the cell?
a. lipids that are placed in water do not dissolve.
b. the tail of a lipid is made of carbon and hydrogen.
c. individual lipids in a membrane can rotate freely.
d. lipids are composed of a head and a thin tail.

The embryos of a bird, a reptile, and a mammal are similar in appearance. how does comparing the physical appearance of embryos of different species support the theory of evolution? a. it shows that these organisms share a common ancestor. b. it provides evidence that these organisms eat the same foods.c. it shows that these organisms share the same habitat.d. it provides evidence that these organisms suffered a genetic mutation.

Sally, age 3 months, has a moist, red, vesicular rash on her cheeks, the backs of her hands, and her arms. her mother said sally was constantly trying to scratch the rash and often has difficulty sleeping. her father has a family history of allergic rhinitis and asthma. discussion questions. 1. review atrophic dermatitis from chapter 3 and discuss the pathophysiology of sally’s symptoms. 2. why is the father’s medical history significant, and what can sally expect as she grows up? 3. discuss the need to limit scratching, and describe practical methods to achieve this.

American scientist, linus pauling, was one of many scientists racing to discover the molecular structure of dna. pauling initially thought that the molecule was a triple helix. later, james watson and francis crick unveiled their double helix model, which turned out to be an accurate description of the molecule's shape. why did watson and crick succeed when pauling failed?