bio questions

[ippie]

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#1. normal wings are dominant to curly wings in certain fruit flies. To determine the genotype of a fly with normal wings, the following test corss should be condected.
a. cross with fly with normal wings
b. cross with fly with normal wings with parents with normal wings
c. corss with fly with normal wings with a parent with curly wings
d. cross with fly with curly wings
e. cross with any fly

=> answer is d. but why not c?

#2. which is false about meiosis?
a. chromatids are pulled towards the same poles during anaphase.
b. the second meiotic division is also known as the reduction division.

=> answer is a, but why not b? the first meiotic division (2n -> n) is reduction division. Not the second meiotic division(n -> n). right?

#3. which of the following processes occcurs within the inner mitochondrial matrix?
a. glycolysis
b. pyruvate decarboxylation

=> answer is a, but why not b?

#4. amoebae are classified in which kingdom?
a. monera
b. protista

=> amoeba is protista, right? Kaplan said the answer is monera. kaplan's answer is worng. do you agree?

#5. in the human kidney,
a. salt is passively transported from the loop of henle to the medulla
b. salt is actively transported from the loop of henle to the medulla

==> answer is b. do you agree that? sodium is passively absorbed in thin part of ascending limb, and actively absobed in thick part of ascending limb. right? The thin part is in inner medulla, and the thick part is in outer part. Any body know the special terminology for thin and thick part of ascending limb?

#6. alternation of the diploid and haploid generation doesn't occur in angiosperm? then, why do we say sporophyte generation is dominant in angiosperm?

#7. in oogenesis, one large ovum and three polar bodies are produced? i thought only two polar bodies are produced, not three. which is right?

 

[userah]

uhh...you must be mistaken about #3. Glycolysis occurs in the cytosol, not the inner mitochondrial matrix. Regarding respiration as a whole, glycolysis occurs in the cytosol, krebs cycle occurs in the matrix of the mitochondria and the electron transport chain occurs in the inner mitochondrial membrane.

for #6. Alternation of generations does occur in Angiosperms. It's sporophyte (diploid) dominant. Key word being dominant. It still has gametophyte generation, it's just largely reduced.

For #7, It is two polar bodies, not three. Not sure where you got three from. During prophase I, you get a diploid polar body and during prophase II, you get a haploid polar body

 

[userah]

regarding the kidney question, i wikipedia'd it because I was confused as well. Here's what it says

It can be divided into four parts:

descending limb of loop of Henle The descending limb has low permeability to ions and urea, while being highly permeable to water.

thin ascending limb of loop of Henle The thin ascending limb is not permeable to water, but it is permeable to ions.

medullary thick ascending limb of loop of Henle
Sodium (Na+), potassium (K+) and chloride (Cl-) ions are reabsorbed from the urine by active transport. K+ is passively transported along its concentration gradient through a K+ channel in the basolateral aspect of the cells, back into the lumen of the ascending limb. This K+ "leak" generates a positive electrochemical potential difference in the lumen. The electrical gradient drives more reabsorption of Na+, as well as other cations such as magnesium (Mg2+) and importantly calcium (Ca2+).

cortical thick ascending limb The cortical thick ascending limb drains urine into the distal convoluted tubule.

btw, if you're confused about which parts of the nephron do what, just wikipedia nephron, it gives a chart breakdown of all the segments and their respective functions. very helpful..l

 

[userah]

for #1, i'd say C is wrong because of the mention of "parent" with curly wings? i think the question is more for whether or not you know the definition of "test cross"; which mentions nothing of crossing a parent with homozygous recessive trait,it just says cross with a homozygous recessive.

for #2, i'd say it's A and not B because A is just flat out wrong. No point in picking B when A isn't even close to being right. It pulls chromosomes apart to opposite poles, not the same poles.

and for #4, I agree with you on amoebas being of kingdom protista. I guess kaplan got it wrong.

uhh...i think i answered all of them haha. keep the questions coming, this is good bio review for me. =)

 

[userah]

in other news, the kidney is a real pain in the ***. Too much going on in there and some functions overlap with some features and it begins to get reaaaaally confusing. I think we should just do away with the kidney, on the exam and in the body =P

 

[la brat]

#1. normal wings are dominant to curly wings in certain fruit flies. To determine the genotype of a fly with normal wings, the following test corss should be condected.
a. cross with fly with normal wings
b. cross with fly with normal wings with parents with normal wings
c. corss with fly with normal wings with a parent with curly wings
d. cross with fly with curly wings
e. cross with any fly

=> answer is d. but why not c?

#2. which is false about meiosis?
a. chromatids are pulled towards the same poles during anaphase.
b. the second meiotic division is also known as the reduction division.

=> answer is a, but why not b? the first meiotic division (2n -> n) is reduction division. Not the second meiotic division(n -> n). right?

#3. which of the following processes occcurs within the inner mitochondrial matrix?
a. glycolysis
b. pyruvate decarboxylation

=> answer is a, but why not b?

#4. amoebae are classified in which kingdom?
a. monera
b. protista

=> amoeba is protista, right? Kaplan said the answer is monera. kaplan's answer is worng. do you agree?

#5. in the human kidney,
a. salt is passively transported from the loop of henle to the medulla
b. salt is actively transported from the loop of henle to the medulla

==> answer is b. do you agree that? sodium is passively absorbed in thin part of ascending limb, and actively absobed in thick part of ascending limb. right? The thin part is in inner medulla, and the thick part is in outer part. Any body know the special terminology for thin and thick part of ascending limb?

#6. alternation of the diploid and haploid generation doesn't occur in angiosperm? then, why do we say sporophyte generation is dominant in angiosperm?

#7. in oogenesis, one large ovum and three polar bodies are produced? i thought only two polar bodies are produced, not three. which is right?

#1. All test crosses are done with homozygous recessives (in this case, curly wings); back cross is done with parent generation

#2. chromatids, not chromosomes, ARE pulled to same poles because homologous chromosomes separate, but sister chromatids stay together until anaphase II

#3. this question is messed up

#4. amoebas are protists

#5. salt is actively transported into the medulla from loop of henle

#6. angiosperms technically have alternation of generations.

#7. technically, the first polar body can divide with the second meiotic division.

Kaplan is riddled with problems. Not the best resource. Princeton Review, although not widely available yet, has much more intelligent, conceptual, and relevant info

 

[smile101]

I'll have to say that the testcross could be done with either heterozygous or homozygous recessive. The reason why C is wrong is because they said that one of the parents had curly wings. Now, you can't tell for sure that the fly you are dealing with is homo or het. If the answer had specifically said het for both alleles then it would be correct.

 

[userah]

yea but a testcross is specifically testing the unknown with homozygous recessive. that's the definition of a "testcross" no?

 

[berq87]

Correct, test cross is always performed with the homozygous recessive genotype.