Eulenoids

Question 1

main pigments

Answer 1

chlorophyll a and b
carotenoids

Question 2

primary or secondary endosymbiosis?

Answer 2

secondary from red algae (3+ membranes).

Question 3

nutrition

Answer 3

• Photoautotrophic: Light + inorganic carbon (pigments include chlorophyll a, b, carotenoids).
• Mixotrophic: Light + organic material.
• Heterotrophic: Absorbs organic compounds, engulfs bacteria (phagocytosis).
• Lose chlorophyll in darkness — switches to heterotrophic feeding.

Question 3

structure

Answer 3

• Unicellular, 1 nucleus.
• Flagella: One long for swimming, one short (hidden plays sensory roles).
• Eyespot (stigma): Red photoreceptor for light detection (phototaxis).
• Pellicle: Protein strips (helical pattern) allow movement + flexibility.
• Chloroplasts: 3 membranes (plants have 2), pyrenoids help make paramylon.
• Contractile vacuole: eliminate excess water accumulated from osmosis

Question 3

movement

Answer 3

• Metaboly: Unique peristaltic motion (flexing and reshaping of the cell). Enables by felible pellicle (protein strips under cell membrane)
• Microtubules + actin filaments drive this movement.
• Cell covering – composed in proteinaceous strips arranged in a helical pattern benteatj cell membrane

Question 4

representative genera

Answer 4

Euglena salina, Eutreptiella marina, Eutreptia viridis

Question 4

repoduction

Answer 4

• Asexual only (no sexual reproduction observed).
• Binary fission: Longitudinal cell division.
• Protective cysts formed under harsh conditions (palmelloid stage).and lose their flagella when condition becomes optimal then it comes back