A few difficult biology questions.

Test Preparation SAT Subject Test Preparation
1

<p>1) In fruit flies, white eyes are a recessive sex linked trait. If a red eyed female fruit fly is mated to a white eyed male, the F1 offspring may be which of the following ?</p>

<p>I) 50% red eyed, 50% white eyed for both sexes.
II) 50% red eyed males, 50% white eyed males, all red eyed females
III) 100% red eyed for bith sexes
IV) 100% white eyed males, 100% red eyed females</p>

<p>A) I only
B) II only
C) III only
D) IV only
E) I and III only</p>

<p>2) A cytologist studying onion cells notes that after 12 hours, the amount of DNA in a cell has doubled. Which of the following is the best explanation of the observation ?</p>

<p>A) Metaphase has begun, concentrating the chromosomes in the center of the cells
B) The S phase of the cell cycle has occured</p>

<p>3) Which of the followign statements describes the "true breeding" plants ?</p>

<p>A) When one of these plants self pollinates, all of its offsprings are fertile
B) The plants always reproduce asexually
C) The plants produce a significantly large number of offspring</p>

<p>4) Which of the following is a function of the cell's plasma membrane ?</p>

<p>A) It inhibits the movement of water into and out of the cell
B) It allows diffusion of Oxygen but not Carbon dioxide
C) It traps photos of light
D) It prevents the diffusion of hormones into the cell
E) It permits the free movement of starch molecules</p>

<p>5) Of the following, the determining factor in natural selection is the number of idividuals that...</p>

<p>A) survive
B) are produced
C) migrate
D) reproduce
E) mutate</p>

<p>If you can add a little explanation on why you chose a certain answer, that would be AWESOME !</p>

2

<p>1) Basic genetic question; just complete the Punnet squares.</p>

<p>2) B. S stands for DNA synthesis. The S-phase is part of interphase, and interphase is when DNA is replicated. </p>

<p>3) None of the answers seem correct. True-breeding plants, when bred with another true-breeding plant for the same traits, pass the same traits to all their offspring. </p>

<p>4) None of the answers seem exactly correct. The plasma membrane does not inhibit the movement of water; it controls the movement of water. It allows carbon dioxide to diffuse. Otherwise, how would cellular respiration function? It does not trap photons. It does not prevent the diffusion of all hormones (the question does not differentiate between steroid and peptide hormones). Starch cannot pass through cell membranes passively. </p>

<p>5) I think it’s D. </p>

<p>Where did you get these questions from?</p>

3

<p>Some biology workbook that I have.</p>

4

<p>1) E because the female can be either (X^R)(X^R) or (X^R)(X^r). The male must be (X^r)(Y). List out the different combinations for their offspring. For a pure-bred female fly, all the offspring must have red eyes, and for a hybrid female, it’ll be 50% red, 50% white for both genders.</p>

<p>2) B, IceQube’s explanation is correct.</p>

<p>3) Ehh, none of those answers are correct. True-bred just means that the organism is homozygous. Both its alleles for a particular trait have to be the same - so like either 2 alleles for red eyes or 2 alleles for white eyes. Otherwise it’d be a hybrid.</p>

<p>4) Not sure either. If I had to guess, maybe E.</p>

<p>5) It’s reproduce, but the answers are worded poorly. The answer should instead be something along the lines of “reproduce and have offspring that can also reproduce.” B/c there are postzygotic barriers that can inhibit reproduction in the next generation, such as is the case for a mule.</p>

5

<p>Here are some more difficult questions, thanks for your previous answers btw, I appreciate it.</p>

<p>6) In formulating his theory about natural selection, Darwin used all of the following facts except:</p>

<p>A) Some species of organisms are extinct
B) Recessive alleles can be hidden from natural selection
C) Variation exists within a population</p>

<p>7) The aerobic cellular respiration of glucose is different from the simple burning of glucose in that the aerobic respiration of glucose…</p>

<p>A) release no heat
B) requires no oxygen
C) releases more energy
D) occurs at a lower temperature</p>

<p>8) A chemical compound formed by the combination of one adenine molecule, one ribose molecule and one phosphate group is:</p>

<p>A) ATP
B) Nucleic acid
C) Nucleotide
D) RNA</p>

<p>9) The feathery structures on a dandenon fruit or milkweed seed and the burrs on the cocklebur fruit have which of the following functions in common ?</p>

<p>A) Food storage
B) Seed germination
C) Seed dispersal
D) Ensuring the fertilization of the flower</p>

<p>10) An organism’s interrelationships within its environment constitute its:</p>

<p>A) trophic level
B) dominance rank
C) ecological niche
D) caste
E) habitat</p>

<p>11) Gas exchange in all living organisms require which of the following:</p>

<p>A) Exposure to a source of pure oxygen
B) Specialized structures such as gills or lungs
C) Moist membrane surfaces
D) A surface covered with cilia </p>

<p>12) When protozoa move toward a food source, they exhibit a type of behavior best described as…</p>

<p>A) reasoning
B) taxis
C) imprinting
D) learning
E) insight</p>

<p>13) Which of the following is LEAST consistent with fossil record:</p>

<p>A) Bony fish evolved from amphibians
B) Mammals evolved from reptiles
C) Birds evolved from reptiles
D) Reptiles evolved from amphibians
E) Cartilaginous fish evolved from jawless fish</p>

<p>14) An ecologically sound reason for conserving tropical rain forest is that they:</p>

<p>A) Supply most of the oxygen that humans breath
B) Are an important reservoir of biodiversity</p>

<p>15) Which of the following best describes a unique advantage of the amniotic eggs…</p>

<p>A) It is used by endotherms as a mechanism of retaining heat in the eggs
B) It allows the storage of yolk for developing the embryos
C) It prevents dehydration of eggs in terrestrial environments
D) It facilitates movement of water into and out of the egg
E) It allows the internal retention of eggs by the mother until hatching</p>