Cell Structure and Microscopy Practice Flashcards

Flashcard set based on lecture notes covering cell ultrastructure, cell membrane components, microscope procedures for plant and animal cells, cell classification, magnification calculations, and nuclear organelle functions.

What is cell ultrastructure?

The fine detail of a cell seen using an electron microscope.

What main components make up the structure of the cell membrane?

Proteins and a phospholipid bilayer.

Which diagram illustrates the arrangement of the phospholipid bilayer, receptor proteins, channel proteins, and transporter proteins in a cell membrane?

The structural diagram showing proteins embedded across and on the surface of the phospholipid bilayer.

What is the function of receptor proteins in the cell membrane?

To recognise harmful substances.

What is the function of transporter and channel proteins in the cell membrane?

To allow substances to move in and out of the cell.

What is the primary function of the cell membrane, and how is this property described?

It controls what enters and leaves the cell, a property known as being selectively permeable.

What safety precaution should be taken when using iodine stain to view plant cells under a microscope?

Wear gloves, as the iodine stain could irritate your skin.

What is the step-by-step procedure for preparing and observing a plant cell (onion) slide under a microscope?

1. Using forceps, remove a thin layer of onion (to allow light to pass through).\n2. Transfer this to a glass slide.\n3. Using a dropper, transfer $2/3$ drops of iodine (stains the nucleus darker).\n4. Gently lower the coverslip at an angle (to prevent air bubbles and protect the objective lens).\n5. Place the slide on the stage.\n6. Observe using the low power objective lens and move to high power using the focus wheel.

Which diagram represents plant (onion) cells observed under a microscope with labeled nucleus and cell membrane?

The diagram showing rectangular plant cells with distinct nucleus dots and cell membranes.

What safety precaution is required when using methylene blue stain during animal cell slide preparation?

Wear gloves in case methylene blue irritates your skin.

What is the procedure for preparing and viewing an animal cell (cheek cell) under a microscope?

1. Swab the inside of your cheek with a cotton bud.\n2. Smear collected cells onto a glass slide.\n3. Using a dropper, transfer $2/3$ drops of methylene blue stain.\n4. Gently lower the coverslip at an angle.\n5. Place the slide on the stage.\n6. Observe using the low power objective lens and move to higher power using the focus wheel.

Which diagram shows animal (cheek) cells viewed under a microscope with labeled nucleus and cell membrane?

The diagram showing irregularly shaped cheek cells containing nuclei and surrounding cell membranes.

How do plant cells and animal cells differ in their structural features?

Plant cells have a cell wall, chloroplasts, and a large vacuole, whereas animal cells have no cell wall, no chloroplasts, and small vacuoles.

How are eukaryotic cells distinguished from prokaryotic cells?

Eukaryotic cells have a nucleus and membrane-bound organelles (e.g., animals and plants), whereas prokaryotic cells have no membrane-bound organelles (e.g., bacteria).

How is the total magnification of a microscope calculated?

$$\text{Total Magnification} = \text{eyepiece lens} \times \text{objective lens}$$

If eyepiece lens E is marked $10\times$ and objective lens O is marked $40\times$, and a cell image measures $0.8\,mm$ in diameter under these lenses, what is the actual diameter of the cell?

Total magnification is $10 \times 40 = 400\times$. The actual diameter is calculated as $0.8 \div 400 = 0.002\,mm$.

What are the roles of the nucleus and the nucleolus in a cell?

The nucleus is the control center of the cell, while the nucleolus functions to make ribosomes.

What is the function of the nuclear pores in the double nuclear membrane?

They allow substances to move into and out of the nucleus.

What is the distinction between chromatin and chromosomes as defined in cell structure?

Chromatin consists of elongated chromosomes, whereas chromosomes are short threads of DNA and protein on which genes are found.