<li><p>In most cells, therea re electrochemical gradients of many ions across the plasma membrance even though there are usually only one or two electrogenic pumps present in membrance. the gradients of the other ions are most likely accounted for by?
a.cotransport proteins.
b.ion channels.
c.carrier proteins.
d.b and c
e. a,b, and c</p></li>
<li><p>the chemical reactions involved in respiration are virtually identical between prokaryotic and eukaryotic cells. in eukaryotic cells, atp is synthesized primarily on the inner membrance of the mitochondria. where are the corresponding reactions likely to occur in prokaryotic respiration?
a.in the cytoplasm.
b. on the inner mitochondrial membrance
c. on the endoplasmic reticulum
d. on the plasma membrance
e. on the nuclear envelope…</p></li>
<li><p>the original modelfor the bilayer structure of cell membranes, which was prepared in the 1920s, was based on which of the following?
a. detailed electron micrographs of freeze-fractured membranes
b. the presence of proteins as a funtional component of biological membranes.
c. the observation that all membranes contain phospholipids and proteins
d. the understanding that phospholipids are amphipathic molecule
e. a and b only</p></li>
</ol>
<p>an anchondroplastic male dwarf with normal vision marries a color-blind woman of normal height. the man’s father was six-feet tall, and both the woman’s parents were of average height. achondroplastic dwarfism is autosomal dominant, and red-green color blindness is x-linked recessive. they have a daughter who is a dwarf with normal color vision. what is the probability that she is heterozygous for both genes?
a,0
b,0.25
c,0.5
d,0.75
e,1.00</p>
<p>now im trying to study ap bio test but dont have money to buy the guidebook for now…so until i buy the book i have to study from internet…</p>
<p>dwarfism is autosomal dominant, so that tells you that the girl has to have at least one gene from her father to be a dwarf. also, if her mother had the gene for dwarfism, it would be expressed, because it is a dominant gene. but the mother is of normal height, so she has two normal height genes. so the mother can only pass on a normal height gene to the daughter. and since the daughter is a dwarf, this means that she got the dwarf gene from her father and the normal height gene from her mother. she is definitely heterozygous for this trait.</p>
<p>so red green color blindness is an x linked trait. this means its on the x chromosome. since the dad only has one x chromosome (men are XY), and his daughter is a girl, she only has one choice of which x chromosome to receive. since the dad has normal vision, his x chromosome has the normal vision gene. so he passed this to his daughter. now, the mom, on the other hand, has two x chromosomes. she is colorblind. its a recessive trait, so she has to have two genes for colorblindness. so, she only has one option to give her daughter: an x chromosome that has the colorblind trait. so the daughter is heterozygous with one normal gene from her dad and one colorblind gene from her mom.</p>
<p>hopefully this helps. its 1 am so my posts are very rambly.</p>
<p>If you truly want to learn the material for the exam, figure out what you think the answers to 1 - 3 should be and why, and then I can tell you if you are correct.</p>
<p>can someone explain the answer to number one? we just learned this in class and had a test on it. that question was SUPER confusing - i think that's what the problem was.</p>