Answer:
Microtubules
Explanation:
These filament-like structures are a major component of the cytoskeleton of the cell and help is maintain asymmetrical cell shape. They are composed of tubulin molecules arranged to form a 'hollow straw' attached to the cell membrane end to end . The contraction and lengthening of these microtubules are controlled by the addition of removal these of tubulin molecules to vary its length.
Shelled protozoans became part of 7 layers
The organelles that scientists believed that it originated by symbiotic relationships between primitive eukaryotes and certain prokaryotes is known as chloroplast. Chloroplast contain chlorophyll which capture energy from sunlight that is used in photosynthesis .This energy is converted to ATP and NADPH
