Which of these observations scientists develop the cell theory?
o a) all cells have dna.
ob) many different types of cells have organelles.
oc) cells are modified for different functions.
od) all parts of a plant are made of cells.

All parts of a plant are made of cells.

All parts of a plant are made of cells.

Explanation:

Cell theory was developed by Sheildien and Schwann. The cell theory states that cell is the functional and structural unit of the living organism. All living organism are made of cell.

The scientists discover that all parts of plants are made of cell. Later, found that not only plants but all the living organism are made of cell. Cell perform all the basic necessities of life. The new cell arise from the pre existing cell.

Thus, the correct answer is option (D).

an organism's phenotype is the  form of a trait  that it  displays. for  flowercolor, a pea  plant  can  display  a phenotype of purple or white flowers. an organism's  genotype  is the alleles of a gene it contains. based on his data, mendel concluded that a phenotype can be  determined  by more than one  genotype.