Jt2008 said:Yeah thats exactly right about xylem ( water and dissolved mineral ions) and its also a passive process.
where as phloem actively transports water and sugars (sucrose) via translocation around the... tree haha. Hope that helps...
One Q: About techology in relation with evolutionary relationships...
Are DNA sequencing and Amino acid sequencing the same?
And what other examples are there besides these and carbon dating?
Cheers
Ps. I cant wait to finsh my hsc and have a beer or three...or 700 haha
taenaisis caused by tapeworm (tanaea)hoochiscrazy said:Name a disease caused by a macro-parasite.
lol easy way to remember is to think of worms, lots and lots of worms!!hoochiscrazy said:Name a disease caused by a macro-parasite.
ok thanks that makes sence now lol.midifile said:Yep thats right, except the water has minerals dissolved in it, so thats why takuto said "water and mineral ions"
lice infestation from lice hahahoochiscrazy said:Name a disease caused by a macro-parasite.
How does an eye accommodate for objects of varying distances?dolbinau said:Who wants to post communication questions, if a lot of you (and statically you probably are) doing that option
dolbinau said:Who wants to post communication questions, if a lot of you (and statistically you probably are) doing that option
A gene refers to the position on a chromosome which codes for a particular characteristic e.g. eye colourhoochiscrazy said:Provide a definition and distinguish between the terms allele and gene?
prelim? whats prelim?Lucid Scintilla said:Hey, out of curiosity, how many of you guys have actually studied for the HSC and the Prelim course?
hmm.lil-monkey said:i thought the xylem transported water up the stem from the roots to the leaves. and its passive transport. the transpiration-cohesion-tention mechanism.
or it that the phloem???
EDIT: yeah it does transport both water and minerals... but is above still correct ?
im so confused about the xylem and phloem.
could someone say
what each transports,
what each mechanism is called and how they work.
thanks =]
thats from the contracting(for close objects) and relaxing( for far objects) of the ciliary muscle, causing the slackening(for close objects) or tention(for far objects) of the ligaments attached to the lens, forcing the lens to become more spherical (for close objects) or flatter( for far objects)JosephW said:How does an eye accommodate for objects of varying distances?
Accommodation is achieved by changing the refractive power of the lens. At close distances, light diverges and the lens must have maximum refractive power to focus the light on the retina. This is achieved when the ciliary muscles contract; the ciliary ligaments become loose and the lens has a rounded shape. For light at long distances, the waves are almost parallel and minimum refractive power is needed. The muscles relax, the ciliary muscles tense and the lens is pulled flat, allowing light to be focused on the retina. This insures visual acuity for light at varying distances.JosephW said:How does an eye accommodate for objects of varying distances?