Laboratory activity 3 (post lab)

LABORATORY ACTIVITY 3.1THE STRUCTURE OF THE CELL

A POST LABORATORY DISCUSSION

OBJECTIVES OF THE LAB. ACT.At the end of the laboratory period, you

should be able to:Locate the parts of the plant cell.Identify the parts of the cell.Describe the parts of the plant cell.

RESULTSCellular organelles seen in Fanwort Leaf

(Cabomba caroliniana)1. Cell wall - it is the outer most layer of the

cell.2. Chloroplastids or chloroplasts – it was

observed as a spherical or globular green structures inside the cell.

Cellular Organelles seen in Onion Leaf (Allium cepa)

1. Cell wall – it is the outermost layer of the cell.

2. Nucleus – a dark small spherical staining body

inside the cell.

DISCUSSION1. Review: Give two differences/distinctions

between a plant and an animal cell? (2 points)Possible answers could be the presence of

cell wall in plants but absence in animals, the presence of chloroplastids in plants but

absence in animals.

DISCUSSION2. What are the specimens used in this experiment?Give the scientific name and common name of each.Cabomba caroliniana – FanwortKingdom: PlantaeSubkingdom: TracheophytaDivision: MagnoliophytaSubclass: MagnoliidaeOrder: NymphaealesFamily: Cabombaceae Genus: CabombaSpecies: Cabomba caroliniana GrayCommon Name: Carolina fanwort, fanwort

DISCUSSIONAllium cepa L. – Garden onionKingdom: PlantaeSubkingdom: TracheobiontaDivision: MagnoliophytaClass: Liliopsida Subclass: LilidaeFamily: AmaryllidaceaeGenus: Allium L.Species: Allium cepa L. Common name: Garden onion

DISCUSSION3. What is the purpose of the crystal violet

dye? Explain.The crystal violet dye is used to enhance the

contrast in the microscopic image seen. It was used to highlight the biological structures (organelles) in the specimens.

The dye reacts with certain organelles only.

DISCUSSION4. Why do you need very thin sections of the

specimens to be observed in each specimen?We need to make the specimens thin enough

to allow light to pass through. If the specimen is thick, not enough light will be able to pass through resulting to a blurry image.

DISCUSSION5. What cell parts have you observed in the

specimen?Fanwort – Cell wall, cell membrane and

Chloroplastid.Garden onion – Cell wall, cell membrane and

Nucleus.

Fanwort – Scanner – 40x

Fanwort– LPO – 100x

Fanwort – MPO – 400x

Fanwort – OIO – 1000x

Anacharis sp. 1000x

(oil) magnificati

onObservable parts:

chloroplasts, cell wall

Garden Onion – Scanner – 40x

Garden Onion – LPO – 100x

Garden Onion – MPO – 400x

Garden Onion – OIO – 1000x

Allium cepa 1000x (oil) magnificati

onObservable

parts: nucleus, cell wall

GARDEN ONION – OIO – 2000x

Allium sepa 2000x (oil) magnificati

onObservable

parts: nucleus

Nucleolus?

END