Question

what is the chemical substance used to indicate the presence of lipids?

• iodine
• biurets reagent
• benedicts reagent
• sudans stain

question 8
which cells does not have a cell wall?

• carrot cells
• potato cells
• elodea cells
• cheek cells

question 9
which of the following cell structures were you able to view floating within the cytoplasm of the elodea cell?

• chloroplasts
• chromoplasts
• amyloplasts
• nucleus

Explanation:

• For the first question, Sudan's stain is specifically used to detect lipids as it has an affinity for lipid - containing structures. Iodine is used for starch detection, Biuret's reagent for proteins, and Benedict's reagent for reducing sugars.
• For the second question, plant cells like carrot, potato, and Elodea cells have cell walls. Cheek cells are animal cells which lack a cell wall.
• For the third question, Elodea is a plant, and chloroplasts are the organelles responsible for photosynthesis and can be seen floating in the cytoplasm of Elodea cells. Chromoplasts are mainly for pigmentation other than green, amyloplasts are for starch storage, and the nucleus is not typically seen "floating" in the same way as chloroplasts in a general light - microscopy view of Elodea cytoplasm.

Answer:

• First question: D. Sudan's stain
• Second question: D. Cheek cells
• Third question: A. Chloroplasts