Hw sucks..need help (math/genetics)

NYSpeed Automotive NYSpeed Off Topic
1

ok…so im taking this online biology class…im almost done with it and it completely sucks…im about to rip my hair out cuz ive been reading all day…and i cant even seem to do this right now even though ive been learning more difficult material all day…

i suck and really dont enjoy doing probability…anyone bored and could possibly help me out? thanks… :smiley:

when all else fails…ask NYSpeed… :lol:

  1. (10 points) Calculate the probabilities of the events described below. Be sure to show your work, and do not use Punnett squares.

a. Four normal pennies are tossed simultaneously. What is the probability that all four will come up heads?

b. What is the probability that the same four coins will come up either all heads or all tails?

c. In guinea pigs, black coat color (B) is dominant over white coat color (b). When a true breeding black guinea pig is crossed to a true breeding white guinea pig, what fraction of their progeny will be black?

d. If two heterozygous black guinea pigs are crossed, what fraction of their progeny will be black?

e. The lack of pigmentation (albinism) in humans is the result of a recessive allele (a) and normal pigmentation is the result of its dominant allele (A). Two normal parents have an albino child. Determine the probability that the next child is albino.

f. The genotypes of two individuals in a tetrahybrid cross are AABbCCDd and AabbccDD. What fraction of their offspring would be heterozygous for all four traits? (Assume independent assortment for all four traits.)

2

thats shit I learned in middle school.
Haven’t used it sense.
Never will.

Sorry!

3

awww boo thanks anyways jack…you got my hopes up when i saw someone replied :stuck_out_tongue: BAH!

4

a. 1/16
b. 1/8
c. 75%
d. 75%
e. 25%
f. i stopped reading this looks like too much effort

5

yeah those 1st two were too easy.

6

awesome! thank you so much! :smiley:

what about?
2. (20 points) The absorption spectra from pigments extracted from two different types of plants A and B have been determined. The absorption data are shown below, where high, medium and low refer to the amount of light that is absorbed by the plant pigments.
Absorbance

Wavelength of light Plant A Plant B
350 nm low medium
400 nm (violet) med med-high
450 nm (blue) high med-high
500 nm (green) low h igh
550 nm (green) low med-high
600 nm (yellow) med med
650 nm (orange) high low
700 nm (red) med-low high
a. What color is each plant? Explain.

b. Leaves from each of these plants are each placed in a closed system container that has a small opening through which one can measure photosynthesis-derived oxygen production. What will the results be for each plant if light only in the 650 nm range is supplied? 500 nm range? 450 nm range? Explain. (Hint, the results would be data for action spectra.)
:smiley: :smiley: :smiley:

7

I think C is 100%
if you do the square all 4 come out Bb

8

I would think plant A is green… since it is not absorbing much of that color it must be reflecting it right? and plant B is yellowish orange (based on the same logic)

For the second part I think the higher the absorbtion the higher the rate of photosynthesis.
650- plant A high photo plant B low photo
500- A low B- high
450- A high B-high but not as high as A

9

thanks a ton! :smiley: muchly appreciated.

10

ha ha sucks to be you :smiley:

jk dont give me anotehr black eye :stuck_out_tongue:

11

any takers on these? :smiley: kthanksyourockplease! :wink:

  1. (20 points) Determine whether the following statements are true or false. If false, briefly explain why.
    a. Due to light-driven electron transport in the chloroplast, the thylakoid space is more acidic than the stroma.
    True
    False (Why?)
    b. Both C4 and CAM plants minimize photorespiration by bypassing the use of rubisco in the first step of carbon fixation.
    True
    False (Why?)
    c. Cyclic photophosphorylation involves both photosystems I and II, and results in the production of NADPH, O2, and ATP.
    True
    False (Why?)
    d. The Calvin cycle enzymes are embedded in the thylakoid membrane of the chloroplast.
    True
    False (Why?)
    e. During metaphase I of meiosis, tetrads (pairs of homologous chromosomes) align in random order at the metaphase plate.
    True
    False (Why?)
    f. During metaphase of mitosis, tetrads (pairs of homologous chromosomes) align in random order at the metaphase plate.
    True
    False (Why?)
    g. The cell cycle refers to the ordered sequence of events (G1, S, G2, and M phases) in the life of a dividing cell.
    True
    False (Why?)
    h. If a gene is located on the X or Y chromosome it must encode a protein that directly contributes to sex determination.
    True
    False (Why?)

these were the last ones…promise… :slight_smile:

12

e. f. g. true
h. false

pretty sure on those. if no one else answers the rest, ill take a shot.

13

Start asking some math theory I feel so left out. :cry:

14

Wanna talk Markov chains? Or HMMs?

15

i got them and sent them in already…thanks guys! :slight_smile:

16

With the Black/white dominance one, they would all be black. If the black one is dominant over white, then all the offspring will be shades of black.

17

Shades of color with black/white would only come into play is in incomplete dominance. Using simple Mendelian dominance, there would only be white and black.

C. 100%, breeding a homozygous dominant with a homozygous recessive
D. 75%, breeding two heterozygotes