ooofff!!! bio izz drivin me nutss!!!! PLZZ HELP!!

[darknight_007]

can any 1 solve da followin qeston????? plz....
1) expalin how variation in 1 species may evntually lead to da development of 2 seperate species? [4] ( 0/N/02)
2) describe the parts played by the uterus in the development of an embroyo 4rm the tym of ovulation to the birth of the baby. [7] (O/N/02)
3) describe the main use of fermenters in the production of
i) antibiotics
ii) single cell protein [6] (O/N/02)
4) suggest wy some insects that r parasitic on plants obtain their food from pholem rather than xylem? [3] (M/J/04)
5) xplain hw the lungs r provides with a continuos supply of clean, atmospheric air? [6] (M/J/04)
6) describe & xplain wht might happen 2 a persons breathin as they climb up a mountain ? [4] (M/J/04)
7) xplain hw N2 in the muscle of a hervivore may be recycled 2 from protein in another hervivore some yrs later?? [7] (M/J/04)
8) xpalin hw activites of some bacteria form a part of both the carbon & n2 cycle. [3] (M/J/04)
9) describe the parts played by genes in the process of evoluton. [6] (M/J/04)
10) xplain hw the knowledge of genetics has helped breeders 2 improve the quality of wool produced by the sheep? [6] (M/J/05)
11) xplain hw variaton can occur in a natural population of organism? [4] (M/J/05)
12) describe & xplain the effect of a gradual increase in temperature on an enzyme controlled reaction. u should refer 2 'lock and key hypothesis'? [5] (M/J/06)
13)describe hw antibiotics may be manufactured on a large scale? [7] (M/J/06)
14) describe the evnts that occure after the body temperature falls that will return the body temperature 2 normal? [7] (O/N/06)
15) xplain hw mosquito r able 2 transmit dieaseses that affect humans. [5] (O/N/06)
16) describe the played by artifical selection in the production of a named economically important plant or animal. [6] (O/N/06)
17) with reference to reference to named exmple, xplain why asexual reproduction in plants is of commercial importance. [4] (O/N/06)
18) name the main blood vessel carrin blood 2 & from the liver & describe any difference thata there may be between the composition of blood as it enters & leaves liver? [7] (M/J/07)
19) xplain wy smokin izz no longer regarded as
i) advisable 4 maintainance of gud health [8]
ii) socially acceptable [2] (M/J/07)
20) describe hw energy from sun is trapped by plants and is eventually used for person 2 move their arm? [10] (O/N/07)
21) although skin is a waterproof structure a few chemicals r able 2 pass through the tissu of the skin. when a person places a finger in a soluton of 1 of these chemicals , it is possible for that chemical to enter the circulatory system & be carried 2 the toungr. the person then experiences a sensatio of taste...
a) describe the pathway followed by this particular chemical from the finger until it reaches the tounge. [7]
b) describe the parts played by the nervous system 2 enable the person 2 experience the taste. [3] (M/J/08)


PLZZZ ANY1 CAN GIVE THE ANSWERS OF THESE QUESTION!!!I DNT NEED THE MRK SCHEME!! I'LL BE GR8FULL 2 U ALL!!! I KNW ITSS HUGE BUT PLZZ HELP ME OUT!!!! I REALLY NEEDD UR HELP ( ESPECIALLY ZOHAIB BHY)

 

[PlanetMaster]

Bio isn't my subject but replying to this list can take more time than an actual exam.
Those who can help plz reply for at least 5 points each.

 

[Arshiful]

1) expalin how variation in 1 species may evntually lead to da development of 2 seperate species? [4] ( 0/N/02)

1. in nature due to limeted resources, der iz alwys compttion btwn organisms.this results in the survival of the fittest.the fittest undergo certain changes in their structure or under go mutation to make maximum use of their available resources. This is known as variation. The members of the species those who do not make any adjhustments either remain unchanged or they perish.ex. from original antelope , two distinct races giraffe and dik dak evolved , dik dak continued to be grazers giraffes evolved long necks to reach out for higher branches of trees.

 

[hassam]

4) suggest wy some insects that r parasitic on plants obtain their food from pholem rather than xylem? [3] (M/J/04)
A N S
phloem-transports food to the other parts of plant(mainly storage) in form of sucrose while xylem transports water and mineral salts.this is 1 reason
phloem lies on the outer side in stem.its walls are thinner and softer as compared to thick lignified walls of xylem
hope it helps

 

[hassam]

http://khanexercises.appspot.com/video?v=GcjgWov7mTM for 1st question.

 

[hassam]

11) xplain hw variaton can occur in a natural population of organism? [4] (M/J/05)
NATURAL SELECTION:there are always different forms of the same species(refer to the example of peppered moths in above video)the one which is best suited to the environment will be selected by the environment(SURVIVAL OF THE FITTEST)see the video on khan academy

 

[Arshiful]

2) describe the parts played by the uterus in the development of an embroyo 4rm the tym of ovulation to the birth of the baby. [7] (O/N/02)

2 after fertlzation
oestrogen------repairs uterus lining after menstruation
corpus leuteum formed helps uterus to be muscular vascular and glandular maintained by progesterone hormone secreted initially
embryo reaches lining by peristalsis of oviduct becomes embedded
implantation
amniotic sac and fluid-------develops and help cusion the embryo acts asa shock absorber protects from mechanical injury

finger ;like processes called villi grow from the embryo to the uterine wall form together to be placenta

placenta made partly from embryonic and partly uterine wall
dissolved food, nutritions o2 from the mothers arteriole capillary diffuse to the umbilical vein of the fetus
and also helps to remove m,etabolic wastes from the fetus by the umbilical artery followed by the maternal veins
placenta also produces progesterone to maintain the uterus lining
as the fetus develops with recognizable human feature the gestation period comes to an end
the muscular uterine wall begin to contract occasionally and becomes frequent
and eventually at the end the amniotic sac bursts and fluid is discharged while the fetul head followed by its body is bein g discharged
all the events ocuur within the uterus thus it plays a major role in the fetul development

 

[Arshiful]

let us every one be united and help this poor person dost i am here to help u dont wry ull get an A

 

[darknight_007]

thnx arshiful!!!!
i lyk the answers whch arshiful izz givin PLZZZ Evry1 as arshiful said lets be united and solve these up da ways arshful did!!!!
@hassam~ i will be vry greatful if u give me answers lyk arsiful did!!! COMPLETE ANSWERS!!!
@ zohaib ~ where r u!!! i need u!!! plzz man help me out of these delimma!!!

 

[Arshiful]

3) describe the main use of fermenters in the production of
i) antibiotics
ii) single cell protein [6] (O/N/02)

i)appropriate size of fermenter 100000 to 150000 litres
fermenter filled with a nutrient broth for antibiotic production
then the mould fungus is introduced
ph adjusted between 5 & 6
temp maintained at 25 degree celcius
aeration is important
sporadically the mixture is striired

ii) fungus grown in specially designed fermenters where fungul cell are harvestedfor protein content
temperature maintained at 30 deg celcius
along with glucose and mineral salts
fermenter help to circulate the mixture continuously
later the fungus is filtered off

 

[Arshiful]

dost ryt now i see dat amar 2002 solve e kora hoi nai ami kortesi plus toke pathachi u shud be thankful............

 

[darknight_007]

thxx!!!! bolte bolte amar hat betha hoye galo!!!!!
u need more!!!!
ok!
THNX!THNX!THNX!
happy!!

 

[Arshiful]

5) xplain hw the lungs r provides with a continuos supply of clean, atmospheric air? [6] (M/J/04)

lungs are located in the chest cavity and separated frm the stmch and oder parts of the digestive sys by diaphragm. During breathing inter costal muscle s of ribs contract and relax causing change in voliume of the thorax .
during inhalation rib raised diaphragm lowers
during exhalation rib rlowered diaphragm upore jai intercostals relax
hair trapping dirt
mucus secreted from epithelial linings
epithelium in c ilia consist of ciliated cells
cilia continuously beats upwards moving mucus from throat to pharynx
goblet cells-------------secrete mucus------trap dirt in inhaled hair
hence air is clean as the cilia sweeps it upwards and it is swallowed from the pharynx into the adjacent oesophagus...............wwaakhh thu..........

 

[usman]

sorry to interrupt. But in SCP production no stirrers are used b/c they may break the (weak) hyphae of the fungus which contain nuceic acids that are
reponsible 4 the nitrogen content. dis is dun by bubbling sterile air through the solution which also provides oxygen 2 fungus 4 aerobic respiration

 

[Arshiful]

sry @>>> usman the medium isnt circulated n ur ryt!!

 

[darknight_007]

whch queston izz usman talkin abut???

 

[hassam]

i m also goin to help MY POOR BROTHER.DONT WORRY.NO TENSION
ALL IZZ WELL!!!

 

[darknight_007]

thnx!! 2 u 2 hassam!!
plz help me... lyk arshiful did!!!

 

[usman]

14) describe the evnts that occure after the body temperature falls that will return the body temperature 2 normal? [7] (O/N/06)
Ans:
- process of vasoconstriction occurs which involves constriction of blood vessels taking blood to the skin. in this way less heat is lost or radiated 2 the surroundings 4m the skin surface. also the blood is insulated below the fatty layer of adipose tissue.
- hairs b'cum erect due 2 contraction of erector muscles. The hairs stand (forming goose pimples in man) and trap a layer of air next 2 the skin. This layer of air acts as an insulator and reduces heat loss (mainly by convection)
- also the process of thermogenesis or shivering starts which involves uncontrollable contraction of the muscles. This generates a gr8 deal of heat released through respiration (in muscles)
- sweat production slows down (or sometimes stops) so less water evaporates 4m the skin (surface). so heat lost by evaporation is reduced and more heat is retained.
- liver starts converting glycogen 2 glucose in response 2 release of the hormone adrenalin into the blood (by the adrenal glands). Adrenalin also stimulates increase in metabolic rate as the rate of respiration increases. Thus more heat (energy) is produced
- also the mammal increases its movements or starts doing more exercise. this also means an increase in rate of respiration. this also generates some heat.
in this way the body temperature returns 2 normal

 

[usman]

18) name the main blood vessel carrin blood 2 & from the liver & describe any difference thata there may be between the composition of blood as it enters & leaves liver? [7] (M/J/07)
Ans:
- hepatic artery + hepatic portal vein (2 liver) & hepatic vein (4m liver)
Differences:
- hepatic artery carries more oxygen or oxygenated blood.
- hepatic vein carries more CO2 or deoygenated blood.
- hepatic vein carries lesser hormones (e.g. insulin, glucagon, adrenaline) than hepatic artery as they are consumed or destroyed in the liver).
- hepatic artery carries more amino acids than hepatic vein (b/c they are converted 2 proteins in the liver & the excess are deaminated 2 form urea).
- hepatic vein carries more urea (as a by-product of deamination of a.acids)
-(hepatic) portal vein carries more digested foods including ions, vitamins, water & minerals