MCQ
Nucleus is absent in one of the following.
- ACompanion cell.
- BSeive tube cell.
- CA vessel and tracheid.
- ✓Both B and C.
✓
Answer
Correct option: D.
Both B and C.
A cell usually contains a single nucleus. However, binucleate (eg. Paramecium caudatum), trinucleate (eg. Paramecium aurelia) and multinucleate forms also occur. But in some cell nucleus is absent such as mammalian RBCs and sieve tube cells. They are called anucleate cells. In plants, xylem tracheids and vessels are nonliving and hence they also lack a functional nucleus.
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