Lets discuss questions of NBDE 1

[d dimps]

---

Members do not see this ad.

1). .Which angle does a P Wave makes on ECG?
a). .45 degree
b). .180 degree
c). .0 degree
d). .-45 degree
e). .-180 degree.

2). .What is endogenous cholesterol? Most endogenous cholesterol is converted to?
a). .Glucose
b). .Cholic acid
c). .Steroid
d). .Oxaloacetete
e). .Ketone bodies

3). .Which of the following statement is correct regarding Glioblastoma multiforme?
a). .the tumor is most common before puberty
b). .it is classified as a type of meningioma
c). .it is most common type of Astrocytoma.
d). .Its prognosis is generally more favourablethan Grade 1 astrocytoma.
e). .It is derived from the epithelial lining of ventricles

4). .Which of the following pathological changes is irreversible?
a). .fatty changes in liver cells
b). .karyolysis in myocardial cells
c). .glycogen deposition in hepatocyte nuclei
d). .hydropic vacuolization of renal tubular epithelial cells.

5). .An example of Synergism is the effect of?
a). .insulin and glucagon on blood glucose
b). .estrogen and progesterone on uterine motility
c). .growth hormone and thyroxine on skeletal growth.
d). .Antidiuretic hormone and aldosterone on potassium excretion.

 

[Cindrella]

if plasma colloid pressure decreases then interstial fluid will pull out water n cause edema ??
wen plasma colloid pressure increases ,it will pull water inside.
if hydrostatic pressure of plasma increases then edema will occur
if '' '' of interstitium increases then water goes to plasma

am i rite with these statements ???

Absolutely correct 👍🙂

 

[anniemirza]

thank u all,
i found something just now so pasting it as it is. i think pb2007 you got it absolutely right.

The follicle is an oblique tube that surrounds the root hair. The follicle always extends into the dermis and sometimes into the subcutaneous layer. There are two principal concentric layers of the cells of the follicle walls. There is an outer connective tissue root sheath, which originates from the dermis. There is also an inner epithelial tissue root sheath, which originates from the epidermis.

There are also two parts to the epithelial tissue root sheath: an internal root sheath and an external root sheath. Peripheral cells of the matrix produce the internal root sheath. This layer of cells is destroyed quickly so it doesn’t extend the full length of the follicle. The external root sheath generally contains the same epidermal cells as the skin surface and extends between the skin surface and the hair matrix. However, all of the cells resemble those of the stratum basale where this sheath joins the hair matrix.

Hey gud one teethie👍

 

[anniemirza]

Hey are there any derivatives of 5th and 6th pharyngeal arches??

 

[Svetlana]

Hey are there any derivatives of 5th and 6th pharyngeal arches??

5th disappears
6th intrinsic laryngeal m(exc.cricothyroid)
laryngeal cartilages(exc.thyroid)
recurrent lar.nerve
R and L pulm.art+ductus arteriosus

 

[teethie]

cindrella, u r right.
Peptide hormones are synthesized in the RER
Steroid hormones are synthesized in SER (just adding one more thing: it is synthesised in mitochndria too)

Please Confirm

 

[anniemirza]

5th disappears
6th intrinsic laryngeal m(exc.cricothyroid)
laryngeal cartilages(exc.thyroid)
recurrent lar.nerve
R and L pulm.art+ductus arteriosus

Thanx svetlana👍

 

[pb2007]

As far as i can remember you are absolutely right! 👍

thanks bratdoc n cindrella for the conformation

 

[Cindrella]

@ teethie .. thanks for confirming 🙂

Another Q for people who own wheelers -

Distance from furcation entrance to CEJ ( Root trunk length ) for
1- Maxillary 1st PM - Mesial ________ Distal ________
2- Mandibular 1st M - Buccal ______ Lingual ________

Thanks in advance 👍

 

[teethie]

this is a link from peterson which confirms synovial fluid as an answer to phagocytosis.

http://books.google.ca/books?id=uzZ...pg=PA935#v=onepage&q=tmj phagocytosis&f=false

nice link teethie .so confirmed it's memb ,i'l put one ques abt tmj tomorow ,hav to dig into my notes for it ,it was something abt phagocytosis in tmj ,so am wondering if answer is memb for that too n not synovial fluid .

 

[teethie]

hi pb2007, i was abt to write something abt plasma colloid pressure, but i saw others have confirmed it correct. now i think i have to revise it for myself because i was not agreeing with one statement. seems i am forgettin the concept.

 

[pb2007]

hi pb2007, i was abt to write something abt plasma colloid pressure, but i saw others have confirmed it correct. now i think i have to revise it for myself because i was not agreeing with one statement. seems i am forgettin the concept.

no problem teethie.
thanks for phagocytosis link i was gona put that up but u already gave the answer.

 

[anniemirza]

@ teethie .. thanks for confirming 🙂

Another Q for people who own wheelers -

Distance from furcation entrance to CEJ ( Root trunk length ) for
1- Maxillary 1st PM - Mesial and distal-7mm(since it says half the length of the root-mesial being more occlusal than the distal)

2- Mandibular 1st M - Buccal : 3mm Lingual: 4mm

Thanks in advance 👍

👍

 

[pb2007]

@ teethie .. thanks for confirming 🙂

Another Q for people who own wheelers -

Distance from furcation entrance to CEJ ( Root trunk length ) for
1- Maxillary 1st PM - Mesial ________ Distal ________
2- Mandibular 1st M - Buccal ______ Lingual ________

Thanks in advance 👍

for max 1st premolar

mesial aspect.... root trunk is lonh on this tooth ,makin up abt half of root lenght .bifurcation on those teeth with two roots begin at a more occlusal point mesially than distally.generally speaking, when bifurcated,root is bifurcated for half its total lenght .[page 207}
distal sidebifurcation of roots abrupt near apical third ,with no developmental groove leading to it such as one finds mesially.{208}

 

[pb2007]

facilitated diffusion differs from active transdport in that net transport by facilitated diffusion
1has transport max
2 use atp as energy
3 require conc gradient
4 occurs as endergonic {positive delta g}process

answer marked is 3rd choice.
facilitated is carried by transporter so is there conc gradient involved coz i kept thinkin facilitated is against conc gradient.?
secondly wen they say endergonic rxn ,does that mean that energy is required coz its +delta g??

 

[Cindrella]

for max 1st premolar

mesial aspect.... root trunk is lonh on this tooth ,makin up abt half of root lenght .bifurcation on those teeth with two roots begin at a more occlusal point mesially than distally.generally speaking, when bifurcated,root is bifurcated for half its total lenght .[page 207}In other words, root trunk length on the mesial is shorter as compared to the distal in bifurcated roots EXCEPT Maxillary 1st PM where it is longer on Mesial.
distal sidebifurcation of roots abrupt near apical third ,with no developmental groove leading to it such as one finds mesially.{208}

Please confirm my understanding and pls don't get confused if i am wrong ..

 

[Cindrella]

facilitated diffusion differs from active transdport in that net transport by facilitated diffusion
1has transport max
2 use atp as energy
3 require conc gradient
4 occurs as endergonic {positive delta g}process

answer marked is 3rd choice.
facilitated is carried by transporter so is there conc gradient involved coz i kept thinkin facilitated is against conc gradient.? I also have a problem with this Q...
secondly wen they say endergonic rxn ,does that mean that energy is required coz its +delta g 👍it is also a non - spontaneous reaction ??

Exer - Energy flow OUT - we lose so -ve
Ender - Energy flow IN ( something like weird pronunciation of " enter " lol .. if u think of it ) - we gain energy so +ve

 

[anniemirza]

Please confirm my understanding and pls don't get confused if i am wrong ..

Na na...in 1st pm ,bifurcation on mesial is more occlusal...so dat will make the root trunk shorter on the mesial and longer on the distal comparatively.hope u get it.
The longer the bifurcation length ,shorter the root trunk.

 

[Cindrella]

@ thanks for the value annie... but the values for maxillary 1st PM are confusing me... if it is 7 mm on M and D , that means root trunk length are equal on both sides .. ?

 

[Cindrella]

Na na...in 1st pm ,bifurcation on mesial is more occlusal...so dat will make the root trunk shorter on the mesial and longer on the distal comparatively.hope u get it.

Yes, thank you i finally get it .... Mesial root trunk length is always shorter than distal root trunk length...and there are no exceptions to this 🙂 thank you 👍

 

[Svetlana]

facilitated diffusion differs from active transdport in that net transport by facilitated diffusion
1has transport max
2 use atp as energy
3 require conc gradient
4 occurs as endergonic {positive delta g}process

answer marked is 3rd choice.
facilitated is carried by transporter so is there conc gradient involved coz i kept thinkin facilitated is against conc gradient.?
secondly wen they say endergonic rxn ,does that mean that energy is required coz its +delta g??

diffusion (simple or fasc) always require conc.gradient
simple-they diffuse my themselves(small enough)
fasc-diffuse with the help of proteintransporter(coz it's big or charge doesn't fit or whatever)BUT it is still diffusion!

that's my understanding!

 

[pb2007]

diffusion (simple or fasc) always require conc.gradient
simple-they diffuse my themselves(small enough)
fasc-diffuse with the help of proteintransporter(coz it's big or charge doesn't fit or whatever)BUT it is still diffusion!

that's my understanding!

thanks so much for clearing this doubt.

 

[pb2007]

Exer - Energy flow OUT - we lose so -ve
Ender - Energy flow IN ( something like weird pronunciation of " enter " lol .. if u think of it ) - we gain energy so +ve

cindrella i'm confused here.
kaplan says that endergonic rxns hav +g n require energy to proceed so its non spontaneous rxm ??
do u hav any idea or if someone is clear with this plz help...

in contractile cycle ,dissociation of actinomycin complex results most immediately
1 atp hydrolysis
2release of atp hydrolysis products
3atp replacing adp on myosin head
4 tilting of myosin heads

can someone plz tel me this sequence in short steps coz i'm not clear at what point atp jumps in n does the job.

is it f actin that participates or g actin in contraction,all i kno is that fa actin is filamentous form of actin n g is globular .
would be thankful if someone can put this rite.

 

[pb2007]

Guys,what do you think,is decks enough for "ethics"?

i'm myself lookin for this answer.
any idea people??

 

[Cindrella]

Sorry pb2007... i can't elaborate more on the exergonic reaction and endergonic reactions ... The only this i know about them is -

1- Exergonic - Energy flows out - Delta G is -ve - Its is a spontaneous reaction
2- Endergonic - Energy flows in - Delta G is +ve - it is a Non Spontaneous reaction

 

[pb2007]

Sorry pb2007... i can't elaborate more on the exergonic reaction and endergonic reactions ... The only this i know about them is -

1- Exergonic - Energy flows out - Delta G is -ve - Its is a spontaneous reaction
2- Endergonic - Energy flows in - Delta G is +ve - it is a Non Spontaneous reaction

thanks cindrella so frm this conclusion i think endergonic needs energy to drive rxn .
which enzyme seals nicks in dna
dna polymerase
dna ligase.??

 

[Svetlana]

thanks cindrella so frm this conclusion i think endergonic needs energy to drive rxn .
which enzyme seals nicks in dna
dna polymerase
dna ligase.??

Lygase

 

[teethie]

pb2007 r u clear on question of diffusion?
and delta G question you are asking in relation to what??

 

[teethie]

👍agree

Lygase

 

[pb2007]

pb2007 r u clear on question of diffusion?
and delta G question you are asking in relation to what??

diffusion part svetlana explained that conc gradient exists in facilitated difusion but partical size is big so need transporter but i need help with muscle contraction part.

delta g was last choice given in facilitated diffusion ques only its clear now .

 

[pb2007]

Sorry pb2007... i can't elaborate more on the exergonic reaction and endergonic reactions ... The only this i know about them is -

1- Exergonic - Energy flows out - Delta G is -ve - Its is a spontaneous reaction
2- Endergonic - Energy flows in - Delta G is +ve - it is a Non Spontaneous reaction

cindrella doubt cleared endergonic needs energy to pull the rxn ,confirmed frm kaplan.
what u wrote is absolutly rite👍

 

[pb2007]

Lygase

plz confirm one more thing

dna polymerase ,proofread n fill in the gaps
dna ligase only joins the broken strands so basically anneals
does annealing n nick means same ??

am i rite??

 

[elmos]

non disjunction happens in which phase?
metaphase or anaphase.
thks in advance

 

[teethie]

hi,
agree with svetlana explanation completely.
abt endergonic thing:
it means it requires energy and yes delta G will be positive but only active transport requires energy not faciliatetd difusion.
because active transport is against the conc. gradient
faciliatted diffusion is down the conc gradient , it does not need energy.
therfore all the choices are for active transport eexcept conc. gradient hence the right answer too.

exrgonic reaction is when energy is liberated after reaction takes place and it is delta G -ve. but in active transport, enrgy is not libertaed, it is required. so it is endergonic rxn.

facilitated diffusion differs from active transdport in that net transport by facilitated diffusion
1has transport max
2 use atp as energy
3 require conc gradient
4 occurs as endergonic {positive delta g}process

answer marked is 3rd choice.
facilitated is carried by transporter so is there conc gradient involved coz i kept thinkin facilitated is against conc gradient.?
secondly wen they say endergonic rxn ,does that mean that energy is required coz its +delta g??

 

[pb2007]

non disjunction happens in which phase?
metaphase or anaphase.
thks in advance

i think should be anaphase coz in early anaphase chromatids begin to split longitudinally and Nondisjunction ("not coming apart") is the failure of chromosome pairs to separate properly during cell division
plz correct

 

[pb2007]

hi,
agree with svetlana explanation completely.
abt endergonic thing:
it means it requires energy and yes delta G will be positive but only active transport requires energy not faciliatetd difusion.
because active transport is against the conc. gradient
faciliatted diffusion is down the conc gradient , it does not need energy.
therfore all the choices are for active transport eexcept conc. gradient hence the right answer too.

exrgonic reaction is when energy is liberated after reaction takes place and it is delta G -ve. but in active transport, enrgy is not libertaed, it is required. so it is endergonic rxn.

thanks teethie ,this is what i wanted to confirm endergonic n exergonic in terms of facilitated diffusion n active diffusion.

 

[Svetlana]

i think should be anaphase coz in early anaphase chromatids begin to split longitudinally and Nondisjunction ("not coming apart") is the failure of chromosome pairs to separate properly during cell division
plz correct

👍Agree!

 

[teethie]

Actin-myosin binding:
F-actin combines with myosin to form actomyosin. upon addition of ATP, actomyosin dissociates into its components actin and myosin.

1)myosin has adp and inrganic phosphate.
2)phopshate will get liberated to accelerate tilting step, then
3)adp also gets dissociated
4)atp comes from cytoplasm and replaces adp and then dissocaition of complex results

so answer should be option3.
is it correct or no???.

in contractile cycle ,dissociation of actinomycin complex results most immediately
1 atp hydrolysis
2release of atp hydrolysis products
3atp replacing adp on myosin head
4 tilting of myosin heads

can someone plz tel me this sequence in short steps coz i'm not clear at what point atp jumps in n does the job.

is it f actin that participates or g actin in contraction,all i kno is that fa actin is filamentous form of actin n g is globular .
would be thankful if someone can put this rite.

 

[pb2007]

Actin-myosin binding:
F-actin combines with myosin to form actomyosin. upon addition of ATP, actomyosin dissociates into its components actin and myosin.

1)myosin has adp and inrganic phosphate.
2)phopshate will get liberated to accelerate tilting step, then
3)adp also gets dissociated
4)atp comes from cytoplasm and replaces adp and then dissocaition of complex results

so answer should be option3.
is it correct or no???.

correct teethie ,its 3rd choice ,u explained it so well.thanks....
so atp comes into scene when actin myosin finished the sliding job and attchment of atp will relax the muscle but bringing myosin n actin back to original position .
so in rigor mortis state the atp is missing so body remains stiff coz myosin n actin are in contraction phase

sorry if it all sounds confusing ,am i saying the rite thing ??

so this also means that in sliding filament theory its not atp that is doin the job ,the phosphate in myosin does that n atp helps bringing bak everything to normal position??

 

[teethie]

u got this right. if u want to go too much specific then be clear about atp and atp hydrolysis.
atp causes dissocation of complex and myosin head is dissociated.

hydrolysis of atp will cause repositioning of mysoin head. remmeber word repositioning, this will occur when hydrolysis of atp takes place.

and if no ATP AT ALL,THEN IT IS RIGOR STATE.

I just thought to add little details to you concept becuase choices are given like that .🙂

correct teethie ,its 3rd choice ,u explained it so well.thanks....
so atp comes into scene when actin myosin finished the sliding job and attchment of atp will relax the muscle but bringing myosin n actin back to original position .
so in rigor mortis state the atp is missing so body remains stiff coz myosin n actin are in contraction phase

sorry if it all sounds confusing ,am i saying the rite thing ??

so this also means that in sliding filament theory its not atp that is doin the job ,the phosphate in myosin does that n atp helps bringing bak everything to normal position.

 

[pb2007]

u got this right. if u want to go too much specific then be clear about atp and atp hydrolysis.
atp causes dissocation of complex and myosin head is dissociated.

hydrolysis of atp will cause repositioning of mysoin head. remmeber word repositioning, this will occur when hydrolysis of atp takes place.

and if no ATP AT ALL,THEN IT IS RIGOR STATE.

I just thought to add little details to you concept becuase choices are given like that .🙂

thanks teethie ,u'v presented it in such simple way ,i should'nt forget it now .👍👍👍

 

[elmos]

thks pb2007, svetlana for the answer.

 

[anniemirza]

non disjunction happens in which phase?
metaphase or anaphase.
thks in advance

Non-disjunction occurs in Metaphase in Meiosis-I
http://www.carolguze.com/oldsite/442Cell%20Cycle,%20Mitosis%20and%20Meiosis.htm (4th para)😕😕😕
need confirmation from a reliable source please....

 

[Svetlana]

Non-disjunction occurs in Metaphase in Meiosis-I
http://www.carolguze.com/oldsite/442Cell Cycle, Mitosis and Meiosis.htm (4th para)😕😕😕
need confirmation from a reliable source please....

I knew there should be smth tricky!!!😎

 

[Cindrella]

plz confirm one more thing

dna polymerase ,proofread n fill in the gaps
dna ligase only joins the broken strands so basically anneals
does annealing n nick means same ??

am i rite??

A nick is defined as a break introduced in a DNA strand that can be sealed using DNA ligase.

http://books.google.ca/books?id=KDsubusF0YsC&pg=PA105&lpg=PA105&dq#v=onepage&q&f=false

Anneal according to my understanding is joining ... either complete / partial ...

http://seqcore.brcf.med.umich.edu/doc/educ/dnapr/pg2.html

If we heat up a tube of DNA dissolved in water, the energy of the heat can pull the two strands of DNA apart (there's a critical temperature called the Tm at which this happens). This process is called 'denaturation'; when we've 'denatured' the DNA, we have heated it to separate the strands.The two strands still have the same nucleotide sequences, however, so they are still complementry. If we cool the tube again, then in the course of the normal, random molecular motion they'll eventually bump into each other ... and stick tightly, reforming double-stranded DNA. This process is called 'annealing' or 'hybridization', and it is very specific; only complementary strands will come together if it is done right. This process is used in many crime labs to identify specific strands of DNA in a mixture.

 

[pb2007]

Non-disjunction occurs in Metaphase in Meiosis-I
http://www.carolguze.com/oldsite/442Cell Cycle, Mitosis and Meiosis.htm (4th para)😕😕😕
need confirmation from a reliable source please....

i found something in biochem kaplan notes

until anaphase,each chromosome contains two sister chromatids.after anaphase ,each chromatid is now a seperate chromosome .
even if we look at the diagram chromosomes r still together so i guess in anaphase they start seperating .

what do u guys say??

Metaphase is easily recognizable because during metaphase the chromosomes are lined up at the equator of the cell. Remember that the chromosomes are still duplicated chromosomes during metaphase.

 

[pb2007]

A nick is defined as a break introduced in a DNA strand that can be sealed using DNA ligase.

http://books.google.ca/books?id=KDsubusF0YsC&pg=PA105&lpg=PA105&dq#v=onepage&q&f=false

Anneal according to my understanding is joining ... either complete / partial ...

http://seqcore.brcf.med.umich.edu/doc/educ/dnapr/pg2.html

If we heat up a tube of DNA dissolved in water, the energy of the heat can pull the two strands of DNA apart (there's a critical temperature called the Tm at which this happens). This process is called 'denaturation'; when we've 'denatured' the DNA, we have heated it to separate the strands.The two strands still have the same nucleotide sequences, however, so they are still complementry. If we cool the tube again, then in the course of the normal, random molecular motion they'll eventually bump into each other ... and stick tightly, reforming double-stranded DNA. This process is called 'annealing' or 'hybridization', and it is very specific; only complementary strands will come together if it is done right. This process is used in many crime labs to identify specific strands of DNA in a mixture.

thanks cindrella
another ques
in collagen synthesis we hav two glycosylations steps
1st takes place in ER and 2nd one takes place in golgi apparatus.
is this correct or wrong ?

 

[anniemirza]

i found something in biochem kaplan notes

until anaphase,each chromosome contains two sister chromatids.after anaphase ,each chromatid is now a seperate chromosome .
even if we look at the diagram chromosomes r still together so i guess in anaphase they start seperating .

what do u guys say??

Metaphase is easily recognizable because during metaphase the chromosomes are lined up at the equator of the cell. Remember that the chromosomes are still duplicated chromosomes during metaphase.

Hmm its all so confusing...
I think some say metaphase becoz....in non-disjunction chromosome pair fail to separate...that means they are still at the equatorial plate without seperating...so whr wud u place this stage....definition wise its still metaphase.N anaphase wud be when this whole chromosome starts to move to either of the poles.Makes sense i guess....wad say guyz?

 

[Svetlana]

A nick is defined as a break introduced in a DNA strand that can be sealed using DNA ligase.

http://books.google.ca/books?id=KDsubusF0YsC&pg=PA105&lpg=PA105&dq#v=onepage&q&f=false

Anneal according to my understanding is joining ... either complete / partial ...

http://seqcore.brcf.med.umich.edu/doc/educ/dnapr/pg2.html

If we heat up a tube of DNA dissolved in water, the energy of the heat can pull the two strands of DNA apart (there's a critical temperature called the Tm at which this happens). This process is called 'denaturation'; when we've 'denatured' the DNA, we have heated it to separate the strands.The two strands still have the same nucleotide sequences, however, so they are still complementry. If we cool the tube again, then in the course of the normal, random molecular motion they'll eventually bump into each other ... and stick tightly, reforming double-stranded DNA. This process is called 'annealing' or 'hybridization', and it is very specific; only complementary strands will come together if it is done right. This process is used in many crime labs to identify specific strands of DNA in a mixture.

i remember a Q about it.
if dna have a lot of C-G regions we should...
i answered to rise the temp.of denaturation(coz these bonds are stronger)
but the actual ans. was to rise the temp.of annealing

i didn't really get it

 

[Cindrella]

thanks cindrella
another ques
in collagen synthesis we hav two glycosylations steps
1st takes place in ER and 2nd one takes place in golgi apparatus.
is this correct or wrong ?

First step is Hydroxylation of lysine and proline - in RER
Second step is glycosylation of hydroxylysine - in Golgi Apparatus

There is a difference between hydroxylation and glycosylation right ?!

 

[Svetlana]

thanks cindrella
another ques
in collagen synthesis we hav two glycosylations steps
1st takes place in ER and 2nd one takes place in golgi apparatus.
is this correct or wrong ?

well as far as i know,the following sequence of events occur:
1.ribosomes-peptide chains synthesis
2.RER-triple helix formation(via disulfide bond)+hydroxylation
3.Gilgi-glycosilation
4.Procollagen is secreted from fibroblast
5.extracellular-peptidase+lysil oxidase activity-->tropocollagen formation