Robert Hooke observed the cells through a combination of lenses.
After Robert Hooke, the development of microscopy take place. After the development of the microscopy, scientist were able to observe the features of the cell. In order to formulate a cell theory observation of most of the cells was necessary. So, it was necessary to observe different types of cells from different organism. So, the advancement of the microscopy and observation process required for the formulation of the cell theory was the reason for the delayed development of the cell theory.
Answer:
1.message or impulse sent through the nervous system
2.body or lymph performes the action.
3.muscle contract
4.message received at muscle fibers
5.brain decides the action.
Answer:
The correct answer will be option-D
Explanation:
Pulmonary Surfactant is a complex substance produced by the pneumocytes epithelial II cells in the alveolar sac.
The surfactant is composed of the proteins and lipids which plays a role in keeping alveoli open by reducing the surface tension formed between the air and liquid.
The surfactant act by forming a monolayer surface film which helps reduce the surface tension.
Thus, option-D is the correct answer.
<span>The
answer is color. The colors range from
red, blue and green. Visible light is
composed of Red Orange Yellow Green Blue Indigo Violet light colors which are
visible on a rainbow. It is only by diffraction of white light that these colors can be perceived because
they have different wavelengths.</span>
