Heredity B

[donutsandcupcakes]

We once again encountered a question that we didn't agree with the answer key for.
The question asks how many chromosome pairs are given above after giving a karyotype of a male with trisomy 18. We think the answer should be 23 pairs of chromosomes, but the answer key says 22 pairs of chromosomes.
Please let me know what you think the answer is, along with an explanation as to why it would be that answer.

they will be right if the question said how many pairs of AUTOSOMES, or if the picture did not show sex chromosomes.
In trisomy 18 (or any trisomies) there is only one extra chromosome, not an extra pair. so, it is 22 pairs of autosomes plus and extra chromosome number 18, along with a pair of sex chromosomes.
they would be wrong if they did not specify autosome.

I have attached the link for the question, I feel the test writer could have been more descriptive...
https://docs.google.com/document/d/1QPS ... sp=sharing

[bp31000]

I have attached the link for the question, I feel the test writer could have been more descriptive...
https://docs.google.com/document/d/1QPS ... sp=sharing

ok, they are simply wrong there. if they do not specify autosome, sex chromosome is counted , and that will make the answer 23.

[Phenakism]

Are tRNA, mRNA, and rRNA the only types of RNA which have been asked about? I've seen a ton of others...

[sciencenerd123]

Are tRNA, mRNA, and rRNA the only types of RNA which have been asked about? I've seen a ton of others...

Those are the only ones I'm studying and the only one's i know about.. Which others are you talking about? Did u see them in tests ?bc I didnt

[Phenakism]

Are tRNA, mRNA, and rRNA the only types of RNA which have been asked about? I've seen a ton of others...

Those are the only ones I'm studying and the only one's i know about.. Which others are you talking about? Did u see them in tests ?bc I didnt

I've seen miRNA a lot, sRNA, and snRNA. miRNA has been on every test but sRNA and snRNA are only once.

[sciencenerd123]

Are tRNA, mRNA, and rRNA the only types of RNA which have been asked about? I've seen a ton of others...

Those are the only ones I'm studying and the only one's i know about.. Which others are you talking about? Did u see them in tests ?bc I didnt

I've seen miRNA a lot, sRNA, and snRNA. miRNA has been on every test but sRNA and snRNA are only once.

Oh, thank you for telling us,

[filkuisk]

Do you guys know of any good free online textbooks for Heredity?

[bp31000]

I have attached the link for the question, I feel the test writer could have been more descriptive...
https://docs.google.com/document/d/1QPS ... sp=sharing

the reason for that answer just occurred to me...
answer is 22 pairs, since chromosome 18 is not a "pair" its a "triplet"
so it is 22 pairs + 3

[bp31000]

Do you guys know of any good free online textbooks for Heredity?

you can study from the genetics chapter of openstax biology textbooks
https://openstax.org/details/books/biology-ap-courses
or your school will have campbell's biology, which you can borrow...

[EwwPhysics]

How much do we have to know about protein synthesis for this event?

I would learn a lot about it. It's a very big part of heredity, so I've dedicated about 1/3 of my cheat sheet to transcription and translation. Also, it's one of the more in-depth and complicated parts of heredity, so it's really fun to study and a change from the usual tedious and easy punnett squares On my cheat sheet, I organize my transcription/translation notes with 4 main sections: pre-mRNA processing, mRNA, tRNA, and rRNA. By organizing by type of RNA, I can have both how protein synthesis works and the structure and function of each type.
In terms of how in depth, you honestly won't have to know too much in depth for regionals/states/most invitationals.