Biology...

[__underthesun]

Does anyone get this stuff?

I mean, I get punnett squares and enzymes...but that's about it. The genotypes and phenotypes make me really angry...

...Maybe it's because we're on our third teacher this year.

Our real teacher will be back in Jan. She has a baby now though...And we ran off the sub, because she was stupid and we all wanted to throw bricks at her. Because "we're not stupid, we just ask stupid questions." Uh-huh.

Back to my point. I have a test tomorrow, someone help me, a little thingie to remember the difference between the Genotype Ratios and Phenotype Ratios...Please? I'll give you virtual ice-cream with sprinkles and sauces andddd...a cherry?

Oh, and I totally have meiosis down.

:sealed: i'mgonnadie.

[annn]

No idea haha. I barely got an A in PreAp freshmen bio. I suck at sci hardcore.
My friend is taking AP bio and says it's the hardest class he's ever taken in his life.

[Broken Parachute]

My overall Bio average in Freshman year was 90 and I got an 82 on the Regents. It's not hard stuff if you just constantly study it. Every night just look over everything you've learned and try to stick it in your head.

[Rebs]

I'm in AP bio this year, believe me, it only gets harder.

[richter915]

haha, wimps

AP bio is a breeze compared to AP chem/AP Physics/AP calculus

alright here're some ratios to help you but only apply to specific scenarios:

a monohybrid cross for two heterozygotes (Rr X Rr)

so your punnet square is like so
R r
R RR Rr

r Rr rr

so genotype ratio is?

1:2:1 ...that's just obvious, right?

but what about phenotype ratio? Assuming R is dominant over r...you see THREE boxes with a big R in it, that means THREE OUT OF FOUR will have the dominant trait expressed as the phenotype...so in this case...dominant:recessive is 3:1

for a dihybrid heterozygote cross you essentially have the same setup but you use a dihybrid (RrAa X RrAa)

when you do that cross you'll get a certain genotype ratio which I can't remember off the top of my head...it's something like 1:2:1:2:4:2:1:2:1...but what's easy to remember is the phenotype ratio which is 9:3:3:1..so you'll have nine organisms expressing dominant R and dominant A...3 expressing recessive r dominant A, 3 expressing dominant R recessive a...and only 1 expressing both recessive r and recessive a.

Hope that helped.

[SkaBum14]

Does anyone get this stuff?

I gots a degree in it, cracka.

I love being able to say that now.

[SkaBum14]

AP bio is a breeze compared to AP chem/AP Physics/AP calculus

Truth

[__underthesun]

So the test sucked. Three pages, I bet I got a 2...

Wait. Back it up. My school's grading system is different, for quick reference:
0 - They never saw it.
1 - You aren't even close, but you get credit for trying.
2 - Almost there.
3 - Mastery of assignment.
4 - Honors.
Keep in mind you must keep doing the same damn thing over and over and over, if that's what it takes, until you get it "signed off" to a 3. Yeah, it sucks, because I suck at geometry. My school, also, does not offer AP classes. You're pretty much shit outta luck if you're ahead of everyone else. Seniors/juniors who have gotten all 3 years of math and 3 years of science can take Pre-Cal/Physics. Seriously confusing school.

Okay. You guys took it as freshmen? I'm a sophomore, I took IPC last year...

OH, man, richter915, I only understand about half of that. It looks...interesting...

Fortunatley, I will not be having a semester exam on this...so December 12, it's going to like...blow up inside my brain. I think I'll recover though.

Thanks.

[Rebs]

haha, wimps

AP bio is a breeze compared to AP chem/AP Physics/AP calculus

I'm in AP calc, and find it quite easy

[richter915]

I'm in AP calc, and find it quite easy
calc is easiest next to bio...bio involves no actual thinking though...

[__underthesun]

bio involves no actual thinking though...

It does when you're on your third teacher in one semester.

[Rebs]

calc is easiest next to bio...bio involves no actual thinking though...
It's a lot of memorization and pictures.

[weezer182]

im taking both college bio and calc next quarter. hopefully its not too bad

[richter915]

It's a lot of memorization and pictures.
ya and in my opinion that doesn't constitute any actual knowledge or thought. I know people who can memorize things...might even say they have photographic memory...but they can't do the simplest of math/physics/chem problems...

[sleepygrlgreen]

ya and in my opinion that doesn't constitute any actual knowledge or thought. I know people who can memorize things...might even say they have photographic memory...but they can't do the simplest of math/physics/chem problems...I miss AP Bio. Eh, I think you're wrong with that though dude. Biology IS a lot of memorization, but you also have to make deductions, experiment, research, etc..etc... I guess the intro classes and stuff have you memorize things but it's just to prepare you for the more difficult classes where you do need to be a good problem solver and whatnot. I definitely agree that chem and physics is harder in that sense, but there is definitely more to bio than just memorization. But from what I know...once you get into the higher level Bio classes, calculus does come in handy...with the derivatives and whatnot. so...yay for bio and calc. :(

[sleepygrlgreen]

It does when you're on your third teacher in one semester.i had to deal with that in general chem. you just have to focus more on the material than anything else.

[b e L I E v e]

oh i remember these days

the only thing i learned in bio...is that i didnt learn anything

[annn]

oh i remember these days

the only thing i learned in bio...is that i didnt learn anything


hahaah right on. I don't remember anything from it and my last AP envsci test shows that.

[richter915]

i had to deal with that in general chem. you just have to focus more on the material than anything else.
you are so lame

see in COLLEGE, teachers alternate throughout the semester...but this kid is in HIGH SCHOOL where it's not normal to do this. In fact, the change in professors in college is really useful.

[noodledancer]

OH, man, richter915, I only understand about half of that. It looks...interesting...
he did a pretty good job explaining it. it takes practice to really get it down. it might help to go through & write what the phenotype results from each genotype, so you can count them up. it'll take a bit longer, but you can't go wrong.

RR= red flower
Rr= pink
rr= white

Rr x Rr ---> RR, Rr, rR, rr ---> 1 RR, 2 Rr, 1 rr = 1 red, 2 pink, 1 white
genotype (pairing of alleles) ratio ---> RR : Rr : rr = 1 : 2 : 1
phenotype (flower colour) ratio ---> red : pink : white = 1 : 2 : 1


YY= yellow seed
Yy=yellow seed
yy= green seed

Yy x Yy ---> YY, Yy, yY, yy ---> 1 YY, 2 Yy, 1 yy = 1 yellow, 2 yellow, 1 green = 3 yellow, 1 green
genotype ratio ---> YY : Yy : yy = 1 : 2 : 1
phenotype ratio ---> yellow : white = (1 + 2) : 1 = 3 : 1



RRYY = RRYy = red flower, yellow seed
RRyy= red flower, green seed
RrYY = RrYy = pink flower, yellow seed
Rryy= pink flower, green seed
rrYY = rrYy = white flower, yellow seed
rryy= white flower, green seed

RrYy x RrYy ---> RRYY, RrYy, RrYY, RRYy, RrYy, rryy, rrYy, Rryy, RrYY, rrYy, rrYY, RrYy, RRYy, Rryy, RrYy, RRyy
---> 1 RRYY, 4 RrYy, 2 RrYY, 2 RRYy, 1 rryy, 2 rrYy, 1 rrYY, 2 Rryy, 1 RRyy
= 1 red flower & yellow seed, 4 pink flower & yellow seed, 2 pink flower & yellow seed, 2 red flower & yellow seed, 1 white flower & green seed, 2 white flower & yellow seed, 1 white flower & yellow seed, 2 pink flower & green seed, 1 red flower & green seed
= 3 red flower & yellow seed, 1 red flower & green seed, 6 pink flower & yellow seed, 2 pink flower & green seed, 3 white flower & yellow seed, 1 white flower & green seed
genotype ratio ---> RRYY: RRYy : RRyy : RrYY: RrYy : Rryy : rrYY : rrYy : rryy = 1 : 2 : 1 : 2 : 4 : 2 : 1 : 2 : 1
phenotypye ratio ---> red & yellow : red & green : pink & yellow : pink & green : white & yellow : white & green
= (1 + 2) : 1 : (2 + 4) : 2 : (1+2) : 1 = 3 : 1 : 6 : 2 : 3 : 1


I'm in AP calc, and find it quite easy
i absolutely adored my ap calc classes. ab & bc were two of my favourite classes my senior year.

I miss AP Bio. Eh, I think you're wrong with that though dude. Biology IS a lot of memorization, but you also have to make deductions, experiment, research, etc..etc... I guess the intro classes and stuff have you memorize things but it's just to prepare you for the more difficult classes where you do need to be a good problem solver and whatnot.
i concur. there is a fair bit of memorization, but ultimately it's all about integrating & applying concepts.

[ArTkY_]

Speaking of Bio... I can't wait to take AP Biology 2 next year.

[richter915]

Thanks for explaining all the genotypes/phenotypes. You went into codominance (or incomplete dominance, can't remember which is which right now)...I really didn't analyze that but that's one of the various "exceptions" you should be aware of. Mendel didn't really deal with those kinds of alleles but we do know of them right now. Sex-linked traits...multiple alleles...there're a bunch of exceptions but the key is to get the basics down and know those ratios and why they are that way.

[noodledancer]

Speaking of Bio... I can't wait to take AP Biology 2 next year.
there's another ap bio course!? damn, i got jacked.

[richter915]

there's another ap bio course!? damn, i got jacked.
it might be that his school divides up the AP bio curriculum into a two year thing? Sounds pointless but it's a possibility.

[__underthesun]

I failed my test.

=]

Thanks anyway.

It's okay though, 'cause like only two people I know out of all five periods passed.

Btw, I mean, it makes some sense but my mind is so ... not right. lol I guess. I dont' know. I get things mixed up so easy so much...I don't know. I get the codiminance and incomplete dominace moreso now and I can do punnet squares and I can do the 'type ratios but I might get them backwards. Guess I gotta study harder...maybe.

[noodledancer]

it might be that his school divides up the AP bio curriculum into a two year thing? Sounds pointless but it's a possibility.
that would be nice on some level. i had to do ap bio in a semester. *down side of having a block schedule*

[richter915]

I failed my test.

=]

Thanks anyway.

It's okay though, 'cause like only two people I know out of all five periods passed.

Btw, I mean, it makes some sense but my mind is so ... not right. lol I guess. I dont' know. I get things mixed up so easy so much...I don't know. I get the codiminance and incomplete dominace moreso now and I can do punnet squares and I can do the 'type ratios but I might get them backwards. Guess I gotta study harder...maybe.
with mendelian genetics...the key is to do practice problems...you can't get by just by reading.

[noodledancer]

with mendelian genetics...the key is to do practice problems...you can't get by just by reading.
what he said.

[__underthesun]

richter915:with mendelian genetics...the key is to do practice problems...you can't get by just by reading.

what he said.

Sounds good, I'll give it a try tomorrow because I think we're basically going over what people missed on the test...which wasn't a lot for me but I still only made a 1 (see my...second post on this thread to see how my school does grades.).........

[sleepygrlgreen]

you are so lame

see in COLLEGE, teachers alternate throughout the semester...but this kid is in HIGH SCHOOL where it's not normal to do this. In fact, the change in professors in college is really useful.you be a douche in the face...oh, i think i just stole your term. asswipe. why do i date you???? anyway, i KNOW that this person is in high school...now :) ..i had to deal with it in english class. my original teacher had crone's (sp) disease or something. we had three or so new teachers.

[amillionmiles]

god damn I hate biology.
I think I have like a C in it now.
and then finals are in like 4 days.
I want to kill myself. lol

[richter915]

god damn I hate biology.
I think I have like a C in it now.
and then finals are in like 4 days.
I want to kill myself. lol
what bio u in?

[__underthesun]

god damn I hate biology.
I think I have like a C in it now.
and then finals are in like 4 days.
I want to kill myself. lol

I would've had a final, but like I mentioned...My teacher was out. Her first day back, for my class, was yesterday. And I swear, these last two days, I've learned more than I have the whole time she was gone. For instance, I now know the difference between DNA and RNA, and why there's mRNA and tRNA. And that Uracil means RNA, while Thymine means DNA.

See?

My school doesn't do finals. But good luck, sorry if I'm late on this, and you have my sympathy.

w00t!

[ClapClapSnap]

i feel your pain. i had four teachers for chem my sophomore year. i really shouldn't have passed. my class somehow convinced our last teacher that taking attendance wasn't considered a big deal at our school and by the end of the year i had about 35 absences in just that one class.

plus, it was hard enough to learn chem, nevermind dealing with new teachers all the time. by the middle of year i had given up.