Biology
Assertion (A): Tracheids are made up of elongated dead cells with large cavities without any contents.
Reason (R) : Tracheids provide mechanical support by developing various types of thickenings in their walls.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.
Answer
Both A and R are true but R is not the correct explanation of A.
Reason — A is true because tracheids are elongated, dead cells with large empty cavities.
R is true because tracheids have lignified wall thickenings and therefore provide mechanical support. However, R does not explain A.
Therefore, Both A and R are true but R is not the correct explanation of A is the correct option.
Related Questions
Assertion (A): Lateral (or cambium) meristem is responsible for the increase in the girth (diameter) of the stem.
Reason (R): Cambium is located near the tips of the root and stem and also on the tips of axillary buds where growth occurs at a faster rate.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.
Assertion (A): Collenchyma is composed of long and narrow cells. These cells have very thick walls due to the deposition of lignin.
Reason (R): Collenchyma stores food and provides temporary support to the parts of a plant.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.
Assertion (A): Lymph is a fluid connective tissue which does not contain any blood cells.
Reason (R): Lymph is concerned with transportation and immunity.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.
Assertion (A): Cardiac muscles are striated, uninucleated and branched. Cells are relatively short and located in the muscles of the heart.
Reason (R): Cardiac muscles can contract without outside stimulation and do not get tired easily.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.