Biology 2013ers MARATHONN (2 Viewers)

[hamstar]

Nope, we don't need to know them afaik

Wooh. Someone is making me feel like i haven't learnt anything. :rage:

I feel so screwed?

 

[Menomaths]

Wooh. Someone is making me feel like i haven't learnt anything. :rage:

I feel so screwed?

What? I'm saying we don't need to know them as far as I know.

 

[fionarykim]

Question: What are the differences between a neutrophil and a macrophage? (3 marks)

uhm idk if we need to know this
but i remember reading it off like somebook last year...

neutrophils are basically phagocytes which are produced when it is an acute diseases, so like a disease which lasts for a few days or even a few hours where as macrophones are for diseases that are more chronic and last for longer

 

[fionarykim]

okay someone explain to me again
wth the law of segregation and law of independent assortment means
in like the easiest possible way LOL

 

[LoveHateSchool]

I'd love for this thread to be revived to be a marathon for all our 2014er biology students

To answer the last Q here cause there were quite a few Qs about it in our BOL subforum, I'll xpost my attempt at explanation from another post, and post a new question for the marathoners to attempt at

Here is my explanation:
These two laws were established by Mendel's famous pea plant experiment.

Law of Segregation:
•Law of segregation states that factors(alleles) for the same characteristic occur in pairs in an individual. These pairs separate at gamete formation, so that a gamete contains only one of each factor(allele). I.e take tall versus short pea plants, say a heterozygous individual of Tt undergoes meiosis, one gamete may get a big T allele, while the other has the little T. (When reunited in fertilisation, it will have the two alleles for a trait)
Remember segregation=separation this is for alleles of the SAME trait
The Law of Independent Assortment:
•Either factor of a pair can combine with either factor of another pair.
•Let's extend our pea plant example with a dihybrid cross. Our Tt heterozyogus individual also possesses genes for colour, and he is heterozygous for this as well, he is Gg (green is dominant, gg is for yellow in homozygous form.
•So the key here is that each allele set can be mixed up, TG aren't always inherited together, not are tg etc. This means for our beloved pea plant, he can make four types of gamete. We can have TG, Tg, tG and tg. This allows greater genetic variation.
Remember Independent Assortment is best understood with dihybrid crosses, as it relates to a variation mechanism in genetics.

NEW QUESTION TIMEEEEE! (simple to get the ball rolling again with all of you probably just having started BOL)
Haemophilia is a defect in blood clotting.It is a recessive trait that has arisen from a mutation of a gene on the X-chromosome. A boy with haemophilia has parents who have normal blood clotting. If the parents have another child what is the probability it will be normal blood clotting?

 

[Zeref]

I'd love for this thread to be revived to be a marathon for all our 2014er biology students

NEW QUESTION TIMEEEEE! (simple to get the ball rolling again with all of you probably just having started BOL)
Haemophilia is a defect in blood clotting.It is a recessive trait that has arisen from a mutation of a gene on the X-chromosome. A boy with haemophilia has parents who have normal blood clotting. If the parents have another child what is the probability it will be normal blood clotting?

Haven't done questions on bio before so I'll give this a go.

Drew a punnett square using Xx and Xx. From the results I got 3:1 so I'm going to assume the answer is 75%.

 

[girlworld_club]

Haven't done questions on bio before so I'll give this a go.

Drew a punnett square using Xx and Xx. From the results I got 3:1 so I'm going to assume the answer is 75%.

Remember that haemophilia is a sex linked disease which is carried on the X. I also believe it is recessive (This will only help with allocating letters).

 

[Zeref]

Remember that haemophilia is a sex linked disease which is carried on the X. I also believe it is recessive (This will only help with allocating letters).

It occurs to me this thing might be the pedigree chart thingy which I haven't taken a look at yet. brb

 

[obliviousninja]

ahhhhhh. biology marathonn. brings back the memories.

 

[obliviousninja]

BUMP

 

[bengosha60]

NEW QUESTION TIMEEEEE! (simple to get the ball rolling again with all of you probably just having started BOL)
Haemophilia is a defect in blood clotting.It is a recessive trait that has arisen from a mutation of a gene on the X-chromosome. A boy with haemophilia has parents who have normal blood clotting. If the parents have another child what is the probability it will be normal blood clotting?

The dad is X^H Y and the mum is a carrier X^H X^h. so possibilities are X^H X^H, X^H X^h, X^H Y, X^h Y. 3/4 chance of normal blood clotting.

 

[Rhinoz8142]

New Question
Antibiotics are drugs widely used in most industrialized societies. They are used to treat bacterial infections, are added to animal feed and have been included in plastic products such as sandwich bags

Explain 2 possible effects of this widespread use of antibiotics on the likely spread of disease in the future.

 

[obliviousninja]

Bump