Celluar components originating from endosymbionts organisms living

Main points
1. CC originating from Endo are result of Endo becoming dependent on its host..
2. If organelles have separate DNA , they have originated from B Endo.
3. If M originated from B Endo..??

Let us see the choices..

A. Mitochondria have their own separate DNA.
point 2 :- If A then B. And this choice is If B then A

B. Mitochondria are a kind of organelle.
There is no connection between M and organelle

C. Some bacterial endosmbionts became dependent on their cellular hosts.
M originated from B Endo and point 1 says they are result of Endo becoming dependent on their host. So this must be true. CORRECT

D. Mitochondria are the only organelles with their won separate DNA.
Nothing says so in the para

E. DNA is the result of endosmbionts becoming dependent on their hosts.
DNA are nowhere shown to be connected to Endo becoming dependent on their hosts

C
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VeritasKarishma Hello Karishman, I still cannot see why A is wrong.
chetan2u If we reject A by - If A then B. And this choice is If B then
Then the same should apply for C no?

Correct answer: C.

A: Incorrect. It does not follow that mitochondria are organelles simply because they have originated from endosymbionts; cellular components other than organelles could have emerged from endosymbionts.
B: Incorrect. It does not follow that mitochondria are organelles simply because they have originated from endosymbionts; cellular components other than organelles could have emerged from endosymbionts.
C. Correct. Mitochondria --> cellular components --> originated from bacterial endosymbionts. Cellular components originating from bacterial endosymbionts --> result of the endosymbiont becoming dependent on the cellular hosts. Therefore, some endosymbionts have become dependent on their cellular hosts.
D. Incorrect. As in (A) and (B) it does not necessarily follow that mitochondria are organelles with their own separate DNA, and whether they are does not preclude other organelles with their own DNA existing.
E. Incorrect. The argument only states that organelles with their own DNA are the result of endosymbionts, not that all DNA is.
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First of all, the way the argument is written is not good. It needs to be written clearly.

Cell components originate from endo organisms when endo organism becomes dependent on its host.
Organelles are components of cells with specialized functions.
Organelles, if they have their own separate DNA, originated from bacterial endosymbionts.

If mitochondria (cell components) originated from bacterial endosymbionts -
So we know that mitochondria originated from bacterial endosymbionts. So these bacterial endosymbionts must have become dependent on their host.
Also, can we say whether mitochondria have their own separate DNA? No. First of all, we don't know if they are organelles (cell components with specialised functions). Secondly, even if we did know that they are organelles, we that that organelles which have their own DNA originated from endosymbionts. But can we say that all organelles which originated from endosymbionts have their own DNA? No.
In "If A, then B" statements, 'A implies B' but 'B does not imply A'.


A. Mitochondria have their own separate DNA.

Cannot say.

B. Mitochondria are a kind of organelle.

Cannot say.

C. Some bacterial endosmbionts became dependet on their cellular hosts.

Yes, this must be true.

D. Mitochondria are the only organelles with their won separate DNA.

Cannot say.

E. DNA is the result of endosmbionts becoming dependent on their hosts.

Cannot say.

Answer (C)

KarishmaB ma'am,

What is wrong with my inference. I inferred
"If organelles originated from bacterial endo, they have their own separate DNA".

The final part of the argument mentions "Organelles originated from endo, if they have their own separate DNA"

How is the original inference the opposite of the above?

Please clarify.

Thanks

Note what is the "if clause" and what is the "then clause". Which clause is written first is irrelevant. We can write "If A, then B" or we can write "B, if A". Both mean exactly the same.

Original statement:
Organelles, components of cells with specialized functions, originated from bacterial endosymbionts if they have their own separate DNA.

It means: If they have their own separate DNA, then they originated from bacterial ES.

"own DNA" is the if clause.

If own DNA, then from bacterial ES.

Your inference is the opposite of this.

Understanding the argumnent - ­
Celluar components originating from endosymbionts organisms living within organisms, are the result of the endosymbiont becoming dependent on its host. - Fact. 
Organelles, components of cells with specialized functions, originated from bacterial endosymbionts if they have their own separate DNA. -Fact

The sufficient conditional is - If they have their own separate DNA, then Organelles originated from bacterial endosymbionts. 
If A, then B means
A implies B 
Not B implies not A

But B implies A is not true - saying Organelles originated from bacterial endosymbionts, they have their own separate DNA - is wrong. This is what options A and B confuse.

If mitochondria, components of most eukaryotic cells, originated from bacterial endosymbionts, then it can be inferred that

A. Mitochondria have their own separate DNA. -Distortion. 

B. Mitochondria are a kind of organelle. - We don't even know if "mitochondria" are "Organelles." Distortion. 

C. Some bacterial endosymbionts became dependent on their cellular hosts. - ok

D. Mitochondria are the only organelles with their own separate DNA. - Distortion. Pick the word "Mitochondria" from the question stem, "organelles," and DNA from the argument and create a tricky option. Distortion. 

E. DNA is the result of endosymbionts becoming dependent on their hosts. - Out of scope.