In plants, growth is said to have taken place when the amount of protoplasm increases. Measuring the growth of protoplasm involves many parameters such as the weight of the fresh tissue sample, the weight of the dry tissue sample, the differences in length, area, volume, and cell number measured during the growth period. Measuring the growth of plants using only one parameter does not provide enough information and hence, is insufficient for demonstrating growth.
Which of the following is not correct?
(a) Robert Brown discovered the cell.
(b) Schleiden and Schwann formulated the cell theory.
(c) Virchow explained that cells are formed from pre-existing cells.
(d) A unicellular organism carries out its life activities within a single cell.
Mention the ploidy of the following:
protonemal cell of a moss;
primary endosperm nucleus in dicot,
leaf cell of a moss;
prothallus cell of a fern;
gemma cell in Marchantia;
meristem cell of monocot,
ovum of a liverwort, and
zygote of a fern.
What is the site of gaseous exchange in an insect?