The answer is Paramecium.
The paramecium is a unicellular ciliated protozoan. They are
often found in fresh water and brackish water areas. They have the elongated
shaped that looks like a rod and has the color violet under the stain because it signifies that it is positive.
Th correct answer would be D! Hope this helps
Answer: The length of the cell in millimetres is 0.0015.
Explanation:
Given conversion :

Thus 
Given : Length of the cell = 1.5 micrometers 
To find: Length of the cell in milllimeters (mm)
Length of the cell in milllimeters (mm) = 
The length of the cell in millimetres is 0.0015.
The options of the given question are:
method for DNA delivery
gene construct
efficient selection strategy
tissue culture system
Answer: Tissue culture system.
Explanation:
The role of tissue culture system is not much in case of the transgenic plant. The method of DNA delivery, efficient selection strategy and gene construct are involved in the plant transformation.
But plant tissue culture is not directly involved in the plant transformation. The plant tissue culture is the collection of the techniques which is used to maintain the growth of the plant cells and so it does not plays any important role in plant transformation.
The plant transformation is the introduction of the desired characters into the plant and then the growth of transformed plant takes place in the culture medium. This has no role in the plant transformation or has less role.