The phospholipids of plasma membranes are amphipathic: they have both hydrophilic and hydrophobic regions. The hydrophobic core
of the plasma membrane helps some materials move through the membrane, while it blocks the movement of others. How does the
structure of the cell membrane help to enable its function?

A)The double layer of phospholipids positions the hydrophilic lipid tails on
the inside, away from the external environment and the the watery
cytoplasm.
B)The double layer of phospholipids positions the hydrophilic lipid tails on
the outer edge towards the external environment and on the inner side
towards the watery cytoplasm.
C)The double layer of phospholipids positions the hydrophilic phosphate
heads on the outer edge towards the external environment and on the
inner side towards the watery cytoplasm.
D)The double layer of phospholipids positions the hydrophobic phosphate
heads on the outer edge towards the external environment and on the
inner side towards the watery cytoplasm.

Chapter 11.1 & 11.2 notes section 11.1 1. every living thing has a set of ? inherited from its parents. 2. after becoming a ? , mendel spent several years studying ? and mathematics at the university of vienna. 3. during sexual reproduction, male and female reproductive cells join, a process known as ? . 4. pea flowers are normally ? , which means that sperm cells in pollen fertilize the egg cells in the ? flowers. 5. when mendel crossed plants with ? characters for the same trait, the resulting offspring had only one of the characters. 6. a ? is a specific characteristic, such as seed color or plant height, that varies from one individual to another. 7. filius and filia are the latin words for ? and ? . 8. the offspring of crosses between parents with different traits are called ? . 9.to mendel's surprise, all of the offspring had the character of only ? of the parents. 10. mendel's first conclusion was that biological inheritance is determined by ? that are ? from one generation to the next. 11. scientist calls the chemical factors that determine traits ? . 12. mendel's second conclusion is the ? . 13. the principle of dominance states that some alleles are ? and others are ? . 14. when mendel allowed the f1 plants to reproduce by self-pollination the traits controlled by ? alleles reappeared in about ? of the f2 plants in each cross.

Which is not a characteristic of bacteria? a. they are unicellular. b. they are prokaryotic. c. they are the smallest form of life on earth. d. they are multicellular.

Veins have a much lower blood pressure than arteries. which of these prevents backflow of blood in veins? a. pressure applied by the heart b. one–way valves in veins c. thin muscular walls of veins