question_answer 15)

A common characteristic feature of plant sieve tube cells and most of mammalian erythrocytes is (a) absence of mitochondria                                       (b) presence of cell waif (c) presence of hemoglobin                        (d) absence of nucleus

Answer:

                (d) The common characteristic feature of plant sieve tube and mammalian erythrocyte isthe absence of nucleus. Sieve tubes are the component of phloem and do not containnucleus. Similarly, erythrocytes in mammalian cell also do not posses nucleus. Erythrocytes are the RBCs which helps in gaseous exchange. Mitochondria is absent in sieve tube cells. Pigment hemoglobin is present inmammalian erythrocytes but not in sieve tube cells. Cell wall is made of cellulose and ispresent in all plant cells, and thus absent in erythrocytes.