Wanted to make some things clear... (1 Viewer)

[Aerlinn]

I was reading, and came across several inconsistencies. Being a biology student, I thought, 'waaaa?!' So, I'll put across my queries to you guys, in the hopes you'll clarify things.

It said some odd, biologically incorrect things, in my opinion.
For instance, it said that males were more likely to inherit certain diseases because most of them were associated with the Y chromosome.
I had the impression the Y chromosome carried genes that mostly related to determination of sex. But maybe, there are some diseases associated with that, most diseases are associated with the Y chromosome? This being the reason males are more likely to inherit certain diseases?!

It says that enzymes are involved in digestion. They're not only involved in digestion, right?

And... it says macronutrients are large nutrients required in greater quantities, eg. carbohydrates, lipids, proteins, and micronutrients are small and required in less quantities, eg. vitamins and minerals.
Don't macro/micronutrients refer to mineral salts? Macro being those minerals needed in larger quantities, micro being those minerals needed in smaller quantities. Plus, I don't think it has any to do with how physically large they are...

Hmm...
Some help would be great

 

[moreturyen]

hey i thought i might be able to help you with the sex linked predisposition of disease in males. for males in particular i think that it will be y-linked dominant which would mean that only males could contract it and that there still may be some who do not because of genetic recombination, etc. however i think where you may be getting confused is is with x-linked recessive. diseases that are x-linked recessive are more common in men than in women and women are the prime carrier, passing it on to each of their sons without fail.

x- and y-chromosomes are indeed the chromosomes that determine the sex of an unborn child, but they do not only code for just the sex of the child. like all chromosomes, they carry a large amount of information and each allele and gen set on that chromosome is related to the dominant and recessive characteristics of the parents, including any inheritance contracted diseases.

hope that may have cleared some things up a bit, and if i just confused you, im sorry.

catch ya, Souless Anfractuosity Jones...:wave:

 

[Trebla]

For instance, it said that males were more likely to inherit certain diseases because most of them were associated with the Y chromosome.
I had the impression the Y chromosome carried genes that mostly related to determination of sex. But maybe, there are some diseases associated with that, most diseases are associated with the Y chromosome? This being the reason males are more likely to inherit certain diseases?!

Males are more likely to inherit certain diseases NOT because of the Y chromosome. The Y chromosome is not the primary factor for genetic diseases, in fact such cases are rare. The Y chromosome is significantly smaller in size than the X chromosome so there are very few genes for genetic diseases in the loci of the Y chromosome. The more common genetic diseases are associated with the X chromosome.

X-linked genetic diseases are RECESSIVE. Now with females the only possible way they can inherit the disease is if BOTH their X chromosomes have the gene for it. If only one of their X chromosomes have it, then the phenotype would not be expressed because the allele for NOT having the disease is dominant over the allele for the disease.
In the case of males, the Y chromosome is like a nil genotype. When their X chromosome carries the genetic disease then they will express that disease because they have no other dominant X chromosome to override it. Therefore they only need the ONE X chromosome containing the disease to inherit it, whereas with females, it must be present in BOTH X chromosomes. Thus, males are more likely to inherit genetic diseases than females.

It says that enzymes are involved in digestion. They're not only involved in digestion, right?

Enzymes are used in most, if not all, bodily processes, not just digestion.

 

[Aerlinn]

No, it wasn't confusing, I understand it, moretureyn

Males are more likely to inherit certain diseases NOT because of the Y chromosome. The Y chromosome is not the primary factor for genetic diseases, in fact such cases are rare. The Y chromosome is significantly smaller in size than the X chromosome so there are very few genes for genetic diseases in the loci of the Y chromosome. The more common genetic diseases are associated with the X chromosome.

Enzymes are used in most, if not all, bodily processes, not just digestion.

Exactly what I thought

I'm glad you both agree. All that wrong stuff came out of a health textbook. Gawd, they don't know what they're crapping on about :S

Thus, males are more likely to inherit genetic diseases than females.

I think I should correct you here, Trebla. First up, dominance applies to phenotypes, not alleles I'm pretty sure. Second... I could be wrong... but it is X-linked RECESSIVE conditions that males are more likely to inherit, and females are more likely to inherit X-linked DOMINANT conditions... right?

So I would say males and females are equally likely to inherit genetic diseases, considering this...

PS. Anyone have any insight on that last bit, macro/micronutrients?

 

[Trebla]

I think I should correct you here, Trebla. First up, dominance applies to phenotypes, not alleles I'm pretty sure.

I'm pretty sure dominance also applies to the alleles. For example, say T = tall and t = short, the 'T' is dominant over the 't'.

Second... I could be wrong... but it is X-linked RECESSIVE conditions that males are more likely to inherit, and females are more likely to inherit X-linked DOMINANT conditions... right?

So I would say males and females are equally likely to inherit genetic diseases, considering this...

You are correct about males being more likely to inherit recessive X-linked conditions and females being more likely to inherit dominant X-linked conditions. However, your conclusion is incorrect. X-linked recessive conditions are much more common than X-linked dominant conditions. Very few genetic disorders are caused by X-linked dominant, thus such an occurance of this type of disease is rare.
You might want to check out the table in the following link: http://en.wikipedia.org/wiki/Genetic_disease
Since there are more X-linked recessive disorders compared to X-linked dominant disorders and Y-linked disorders, males are more likely to inherit genetic diseases.

 

[xiao1985]

@aerlinn: ditto trebla... but only your statement is true until the bit about equally likely to inherit genetic disease... otherwise, it's all good...

(though that being said, i have not heard of x linked dominant... but then, i'm no biologist, so who am i to speak?!)

2ndly, statistically speaking, you are correct, aerlinn... for an x linked dominant condition, females are more likely to be infected with it... (if it exist at all)

as for the phenotype/allele thing, i never understood what allele is... so no comment =(

 

[Survivor39]

I think people have explained the genetic questions fairly clearly so I won't try to explain it further.

It says that enzymes are involved in digestion. They're not only involved in digestion, right?

Correct. Enzymes are involved in digestions, DNA replication, repair etc...

And... it says macronutrients are large nutrients required in greater quantities, eg. carbohydrates, lipids, proteins, and micronutrients are small and required in less quantities, eg. vitamins and minerals.
Don't macro/micronutrients refer to mineral salts? Macro being those minerals needed in larger quantities, micro being those minerals needed in smaller quantities. Plus, I don't think it has any to do with how physically large they are...

No. Macronutrients are in fact physically larger. Carbohydrates, proteins, lipids can all be a large polymer made up of repeating units. e.g. starch, a carbohydrate, is made up of many glucose bunits. You need a lot of these macronutients to survive.

Micronutrients are, like you've said, vitamins and minerals, or salts. Although they are essential for survival, you only need a trace amount of them.

To put this in context, if you have a chicken sandwich, you will have two slice of bread (carbohydrate), some lettuce (carbohydrate), chicken (proteins and lipids) and a sprinkle of salt. So a MAJORITY of what you eat are macronutrients and only a small % is micronutrients. Obviously you can't survive eating a sprinkle of spread, lettuce, chicken and a sandwich full of salt, can you?

 

[Trebla]

enzymes r involved in digestion... dont u remember yr 11 bio? geezzz

i cant remember yr 10 science that well... but i remember something about genes for diseases being carried on the y chromosome more than the x... like haemophilia? cant remember

Geez, you are waaaayyyy off....

 

[ari89]

enzymes r involved in digestion... dont u remember yr 11 bio? geezzz

lol you're right...in yr 11 we learnt that in the mouth the enzymes in saliva assist in the digestion of food. (The enzymes start to break down the starches).

 

[xiao1985]

enzymes are really amazing stuff, on a side note... it does so much things chemist want to do but will never do in the next 10 decades (or even 100)...

 

[Ea22.007]

enzymes r involved in digestion... dont u remember yr 11 bio? geezzz

i cant remember yr 10 science that well... but i remember something about genes for diseases being carried on the y chromosome more than the x... like haemophilia? cant remember

they arent only involved in digestion though , coz as enzymes speed up chemical reactions and there are so many different chemical reactions in biology enzymes are used alot of processes besides just digestion

 

[Aerlinn]

They sure are Without 'em, so many of the chemical processes in our body would take soo long to finish, we wouldn't really survive. heheh.
Oh, and ...

No. Macronutrients are in fact physically larger. Carbohydrates, proteins, lipids can all be a large polymer made up of repeating units. e.g. starch, a carbohydrate, is made up of many glucose bunits. You need a lot of these macronutients to survive.

Micronutrients are, like you've said, vitamins and minerals, or salts. Although they are essential for survival, you only need a trace amount of them.

To put this in context, if you have a chicken sandwich, you will have two slice of bread (carbohydrate), some lettuce (carbohydrate), chicken (proteins and lipids) and a sprinkle of salt. So a MAJORITY of what you eat are macronutrients and only a small % is micronutrients. Obviously you can't survive eating a sprinkle of spread, lettuce, chicken and a sandwich full of salt, can you?

I realised that there are two definitions of both macro and micronutrients, that's why I got confused.
The first refers to Carbs, proteins, lipids, vitamins and minerals, and the second one just refers to the minerals only. You get your trace minerals and those you want in greater quantities, I think that applies more to plants... not too certain...

xiao1985: Heh, you shoulda done Biology. Fascinating subject

 

[xiao1985]

i did!!! well in hsc any way...