Science Homework

[box o crayons]

so i need to solve these problems for my homework next week and i need your guys help. i got about half done but i need the rest heres the questions

1.biologists have long been interested in studying the traits of twins.Explain how twins occur. discuss how traits are transferred from parent to offsprin in a asexual reproduction compared to sexual reproduction. use a monohybrid cross to explain your example
2.Explain how desease could be a densit-dependent factor in imaginary population.Name at least two denisty-dependent factors that affect the population when it has reached carrying capacity. Draw a graph of what you think logistic population growth would look like for the population. include the effects that a density-independent event might have on the graph

3.design an experiment that identifies and monitors specific conditions that produces a change in the frequency of disease. explain how mutation of the pathogenic agent can alter the outcome of an emergent disease. what prevention and treatment can change its frequency

 

[nirvanaking95]

so i need to solve these problems for my homework next week and i need your guys help. i got about half done but i need the rest here's the questions

1.biologists have long been interested in studying the traits of twins.Explain how twins occur. discuss how traits are transferred from parent to offspring in a asexual reproduction compared to sexual reproduction. use a mono hybrid cross to explain your example

Main Entry: mono hybrid cross
Part of Speech: noun
Definition: a cross between two genetically identical individuals, a cross between two individuals that are heterozygous for a single trait or gene
...........................................

“the science of humanity,” which studies human beings in aspects ranging from the biology and evolutionary history of Homo sapience to the features of society and culture that decisively distinguish humans from other animal species. Because of the diverse subject matter it encompasses, anthropology has become, especially since the middle of the 20th century, a collection of more specialized fields. Physical anthropology is the branch that concentrates on the biology and evolution of humanity. The branches that study the social and cultural constructions of human groups are variously recognized as belonging to cultural anthropology (or ethnology), social anthropology, linguistic anthropology, and psychological anthropology. Archaeology , as the method of investigation of prehistoric cultures, has been an integral part of anthropology since it became a self-conscious discipline in the latter half of the 19th century

 

[box o crayons]

wow thats a lot but what i need is how twins accur not the definition of a mono hybrid cross but thanks i might need that for another question

 

[BlacRoseImmortal]

Twins occur when the fertilized egg cell splits into two cells within the first couple of days post getting knocked up ^^

And the egg splits for no specific reason.

 

[nirvanaking95]

wow that's a lot but what i need is how twins occur not the definition of a mono hybrid cross but thanks i might need that for another question

Okay, then ...
Those are fraternal twins. They are no more genetically similar than any two siblings. They will not be identical. Identical twins come from a developing that embryo divides to form two separate but identical embryos.

Also this... if that doesn't help...
See, when the zygote undergoes the first round of cell replication, it usually stays together. But at this point, when it's just a couple of cells, it can split in such a way that it forms 2 separate beings (just like amoebas and other asexually reproducing organisms do it) instead of staying together as one. This is rare, but it does happen very early on in development.

I think the second paragraph is better.

EDIT:

Mmmmmm... cookies.

 

[box o crayons]

ok sweet got the first one crossed off thanks

 

[nirvanaking95]

ok sweet got the first one crossed off thanks

No problem.

EDIT:

WOOT! 100TH POST!

 

[Sigma LS]

First one is 3 parts. The first is that the fertilized egg goes through two separate division and growth processess (two people from 1 egg). That's for identical twins. Fraternal twins are just two fertilized eggs (two eggs happen to be fertile at the time of inception). Asexual reproduction is where there is not two sets of genetics involved. It means no sex right. Then the transfer of traits is easily explained in the stages of meiosis.

What your teacher is obviously asking you to do is make a punit square of two clones and show that because of meiosis you can still get offspring with genetic variation compared to the parents even if the parents have the exact same genetics. Then explain that the two types of twins you get is a result of the number of times meiosis takes place. (Two eggs, two, one egg, one)

If you want a fun one. Your answer should also explain why certain female lizards can reproduce without mating but can lay eggs that make male lizards.




Second one is a logarithmic curve of disease incubation time vs. population density. If you have a dense population with a disease of low incubation time then the population will be devastated in a very short amount of time (systemic plague in the wilderness of the western states is a good example). Since this will wipe out almost the entire population, recurrence of outbreaks will be low. If you have a low-density population less dammage but same low occurance. High density and long incubation time means that it will spread further and have even worse effects and have a higher occurance rate because each person it gets passed on to will carry the disease for the entire incubation period.


For the third. Just talk about the communicability of the disease (airborne, waterborne etc.). The incubation time (long or short). The effects (is it like a cold? is it deadly, if so in what percent of people). Treatments (quarantine areas, vaccines, education of the public etc.)

Personally I would do a zombie virus for the third. That would be a fun one to write about!

 

[BlacRoseImmortal]

Chris wins.... and he obviously pays attention in college..... while im sitting here skipping my night class.... damn you Chris for makin me look bad! lol

 

[box o crayons]

wow thanks a lot for that long explanation and yea that would be fun to write about zombies but hes not a very humerous guy and probably wouldnt like that. thanks a ton guys and girls

 

[Sigma LS]

Hehe thanks.

Kelly- Don't feel bad . My old profs would kick my ass if I didn't remember the first one since bio was my minor in undergrad. As to the disease stuff, I had a statistics professor that used to be a government toxins guy back in the day. He would start our review as. "Okay today we'll start with a real world experiment we did during the Vietnam war. The defoliant agent orange appears to have negative effects on humans during deployment in the field. The first step to determine if this might be the case is to use a representative population of mice... "

 

[bilsy28]

I'm a twin! Fraternal twins are just two egg cells. While Identical is one egg cell (I'm not sure if egg cells the right word, but I think it's right ) that was split into two cells. Hope that helps.

 

[222notforu]

My stupid Science teacher decided to give us a BIG surprise...We all have to do a science fair project, with a partner. The only problem is, They made us do 1 last year, and I don't know what too do 1 on this year!
Everyone averages a D in her class...She doesn't teach very well..

 

[box o crayons]

try how far a paintball guns distance varys in diffrent weathers

 

[Bethanxx]

Asexual reproduction is where there is not two sets of genetics involved. It means no sex right.

Ooh we did this,, it's like if you have an amoeba (a single-celled organism) which splits in half; the two halves have exactly the same genetic information and whatnot. Then the two halves split again, into four if you include everything, and that goes on and on and thats how they reproduce! Wouldn't it be easy if that was all we had to do (No, wait...we'd all be clones of each other - forget I said that.)

 

[Bloodl3tt3r]

Ahh, AP Bio. fun fun... NOT!

"2.Explain how desease could be a densit-dependent factor in imaginary population.Name at least two denisty-dependent factors that affect the population when it has reached carrying capacity. Draw a graph of what you think logistic population growth would look like for the population. include the effects that a density-independent event might have on the graph."


Disease is a density-dependent factor because the more dense the population is, the better chance the disease has of spreading to someone else because there are more people within the same area, meaning theoretically they live closer together and interact more often, which means the disease has more of a chance to spread from one person to another.

Two density-dependent factors that would affect population at carrying capacity are disease, obviously enough, and another is the availability of food. If the population is too large for the area they occupy (basically, they've exceeded the carrying capacity), there will not be enough food to sustain a population of that size (competition between members of the species) and some of the population will die out, bringing the population back to about carrying capacity-level.

"3.design an experiment that identifies and monitors specific conditions that produces a change in the frequency of disease. explain how mutation of the pathogenic agent can alter the outcome of an emergent disease. what prevention and treatment can change its frequency"

Since you don't actually have to do the experiment, be as creative as you like. Me, I would suggest taking a well-known bacterium or virus for say, flies (easily expendable test animals, as loathsome as that suggestion sounds. We use Drosophila flies all the time in AP), and introducing it into different closed environments and checking the rate of disease in the flies every day or so. For example, put like, 20 flies each in a normal environment, one with a higher temperature (use a heat lamp or something), one with a lower temperature (keep it in a fridge? but the flies will turn inactive and possibly die due to the cold, so maybe that one's not a good idea), one that's more moist than normal (idk, humidifier?) and one that's drier than normal (I have no idea how to do that one), etc etc. and just check the number of flies that have the disease every day or so.

As for the mutation of a pathogen altering the outcome of the disease, a mutation could (and this is one of many thousands of possibilities) cause it to become resistant to treatments (think MSRA or MRSA or whatever it was), causing the disease to become more prevalent because more people are being affected by it due to lack of an effective treatment. Mutations can have a detrimental effect too, if the mutation were to, say, strip the bacterium of its natural defenses or something, then the disease would become less prevalent, and so on.


Sorry for the novel-length explanations, lol



EDIT: Asexual reproduction is what amoebae do, although it's really just mitosis, which cells are supposed to do anyways. And before someone quotes binary fission at me, that's in prokaryotic cells, I believe. But another example of asexual reproduction is when an organism (as its main means of reproduction) "buds" off a portion of itself and that portion grows into a new organism with all the genetic information of the original.