Came across this UEarth question and I'm trying to figure out how you'd solve this problem without drawing out the whole punnet square (massive waste of time). As I learned it, you could try to solve for the probabilities for each gene individually and multiply them to get your final answer, but I'm messing up somewhere and getting the wrong answer. I'd appreciate any insight on how you should work through a problem like this:
In flies that would normally have white eyes, a dominant mutation that inactivates PTP results in red and white eyes; a dominant Ena mutation yields orange eyes (or red and orange if the PTP and Ena mutations are both present); and a dominant Abl mutation yields elongated eyes.
Females heterozygous for PTP (eePp) were crossed with males heterozygous for Ena (Eepp). F1 generation males and females, each with red and orange eyes, were then selected and crossed with each other to produce an F2 generation. Flies with two mutant Ena alleles (EE), as well as those with two mutant PTP alleles and at least one mutant Ena allele (EePP), did not survive past the larval stage.
A. 1/8
B. 3/8
C. 1/4
D. 9/16
Question 1: Mendel crossed pure breeding, tall, purple flowered plant’s with pure breeding, small, white flowered plants. Determine the progeny.
TTPP= Tall and Purple ttpp= Small and White
Question 2: All the offspring of the F1 generation of the previous cross were tall and purple. If the F1 generation were self fertilized then 4 tall possible plants would be produced: tall purple, tall white, small purple, small white in the ratio 9:3:3:1. Prove this is to be the case.
https://imgur.com/QCEXjVh
My book gives probability of two possible F2 genotypes from a dihybrid cross between two YyRr heterozygotes. Makes sense.
But then, it also gives probabilities of five possible F2 genotypes from a trihybrid cross between PpYyRr and Ppyyrr. What I don't understand is why in the world does it say that for some of the homozygous alleles, it says the probability is 1/4? For ex, in ppyyRr, the probability of yy is 1/2; shouldn't it be 1/4 like in the dihybrid cross? Plus, the Ppyyrr allele probability doesn't even multiply up to 16
For dihybrid, ive been drawing it out everytime. Wondering if there is an easier way to go about it given the time constraint?
And for determining genotypes based on pedigreecharts, any tips besides eliminating all the possible options one by one?
The offspring of a cross show a 1 (AaBB): 2 (aaBb): 2 (AaBb): 1 (aaBB): 1 (Aabb) : 1 (aabb)
I want to find the parents genotype and the complete punnet square. I've tried it on my own but I can't really make sense of the given. Thanks!
At one gene locus in humans there are 2 alleles: one for curly hair and another for straight hair. Neither allele is dominant, and heterozygous individuals have wavy hair. At a second gene locus, 3 alleles control ABO blood type. The alleles at these 2 gene loci assort independently. A man with straight hair and A blood marries a woman with wavy hair and B blood. Their first child has straight hair and O blood. If their second child is a boy with straight hair, what is the probability that he has A blood? ( Express your answer as a percentage. Enter the number only without the percent sign. For example, enter 100% as 100 and enter 12.5% as 12.5 )
This is an online homework assignment and I have tried submitting 25(and 12.5) but that gets marked wrong. Where am I going wrong?
are you equally likely to give your recessive/dominant/either gene?
Ex. Most of the human population is O blood type. A & B are newer, but over time, won't the whole race become A/B? Or is there some sort of preference in handing down the recessive O type in this case, preventing A & B from "taking over"?
Ex. Most of the human population has five fingers/hand, but the gene that codes for six fingers/hand is actually dominant. Why is the majority still five-fingered, then? Is there a preference for handing down the five-fingered trait? Or are six-fingered people just not having enough kids?
e: Even when the sixth finger is removed at birth, that doesn't change the genetics for it.
Given a cross of AaBb x aabb
Progeny: 45 are AB 12 are Ab 8 are aB 52 are ab
What exactly makes them a recombination? Ab and aB are the recombinates according to the answer key, but why isn't AB? Other than the fact that recombination frequency maxs out at 50%.
Thanks in advance!
Can someone please walk me through step by step how to arrive at the answer for this question? I'm so confused.
https://preview.redd.it/i2fnv400ecr71.png?width=1516&format=png&auto=webp&s=4043ef8f5a77042aa17043a1c5097d63a1e542fa
I am having mad amount of trouble understanding and doing dihybrid questions. I am not understanding which allele (whether 4: AaBb or 2: Ab, Ba etc) should go on the sides of the table and which ones on the top. I am even more confused when you have to do a test cross and find the parent. That shit makes 0 sense!!!
Anyone wanna recommend a vid or take on the challenge of explaining this to me please?!
So I’ve run into problems on genetic questions, and I want to better understand the purpose of knowing the 9/3/3/1 breakdown for a dihybrid cross if it only pertains to two parents that are heterozygous for both traits?
Whenever I’ve come across dihybrid questions, the two traits per parent were NOT heterozygous. So, my questions are:
For those questions, can you somehow use the 9/3/3/1? If so, how?
If not, how to quickly do the problems?
Thanks!
Biology is turning into math where; at first you're like "oh, okay, yeah, sure. Punnett squares are pretty simple". Then it escalates to dihybrid crosses and then to incomplete dominance AND THEN to co-dominance. My head's gonna explode and I'm sure this is only the tip of the genetic iceberg in terms of complexity
On top of the title question, how were these techniques developed? Is it just through statistical analysis and sampling?
anybody have a shortcut? always seem to mess this up
My biology teacher explains like I'm a college student.
Can someone help me with this problem? A dwarf, pure yellow podded pea plant is crossed with a dwarf, hybrid green podded pea plant. Yellow pods and dwarfness are recessive. Give the phenotype and genotype of the F1 generation.
Can someone explain to me why dihybrid me can be unlinked and linked? As well as why does the cross test work?
I saw few of his videos and some of them sound convincing, byt his constant arrogance and dunning kruger amkes him annoying.
I don't want to step on anybody's toes here, but the amount of non-dad jokes here in this subreddit really annoys me. First of all, dad jokes CAN be NSFW, it clearly says so in the sub rules. Secondly, it doesn't automatically make it a dad joke if it's from a conversation between you and your child. Most importantly, the jokes that your CHILDREN tell YOU are not dad jokes. The point of a dad joke is that it's so cheesy only a dad who's trying to be funny would make such a joke. That's it. They are stupid plays on words, lame puns and so on. There has to be a clever pun or wordplay for it to be considered a dad joke.
Again, to all the fellow dads, I apologise if I'm sounding too harsh. But I just needed to get it off my chest.
Do your worst!
I'm surprised it hasn't decade.
