Biology Qn..Help

[hana217]

can anyone help me for Qn no 25..http://www.xtremepapers.net/CIE/Cambrid ... 6_qp_1.pdf

 

[carolinetcw]

can anyone help me for Qn no 25..http://www.xtremepapers.net/CIE/Cambrid ... 6_qp_1.pdf

this question is very weird. the mark scheme's answer and its comment is contradicting!

http://www.xtremepapers.net/CIE/Cambrid ... w06_er.pdf

 

[UxaiR]

actually there is a problem in marking scheme
in marking scheme the answer is written wrong

just keep in mind that Ball and socket joint Only rotates

 

[mimmi]

I freaked out a second thinking I'm wrong!

 

[carolinetcw]

but how can two ANTAGONISTIC muscles relax at the same time??

 

[TeKnOzOr]

@carolinetcw : yes caro,its impossible......bcoz if one relaxes , the other one must contract.......!
in the answer C ,all are good but only the ball and socket joint iz not good as it cannot extend.....it only rotates......!!
i think zat instead there must have been Either hinge joint in the place of ball and socket joint Or D must have been like
this : D biceps relaxes , triceps contracts and ball and socket joint rotates

I believe zat this question is wrong....!!!wat do u guys think...?!!??

 

[carolinetcw]

oh i don't know. but when you lift your arm like that , you touch your biceps and you will realise that it's hard. so it must be , biceps contract and triceps relax , if not both relax =( what do you think? B as the answer.. but if you check the marking scheme, answer is C.. but the comment by principal examiner , answer is D.. i don't get it.

 

[TeKnOzOr]

@caro : just forget it dear.....after all it's not your fault......just relax.........
u no zat song nah....???relax...!!take it eaa eaasy.....!!!hahahaaha....Lol..<><><>dnt wry