IB Cell Exam Review

Which of the following correctly describes exocytosis? 1. Plasma membrane increase in size (Y/N) 2. Plasma membrane is pulled inwards (Y/N) 3. Membranes fuse (Y/N) 4. Vesicles move away from plasma membrane (Y/N)

1. Yes 2. No 3. Yes 4. No

A student observes and draws an Amoeba, using the high power lens of a microscope. The diameter of the drawing is 100 mm. The actual diameter of the Amoeba is 100 µm. What is the magnification of the drawing?

1000x

The width of a human hair is 0.1mm. What is the width in um?

100um

If a red blood cell has a diameter of 8um and student shows it with a diameter of 40 mm in a drawing, what is the magnification of the drawing?

5000x

What is the correct order of increasing size for the following biological structures? I. Width of virus II. Width of bacterium III. Thickness of a cell surface membrane IV. Diameter of eukaryotic cell

Cell surface membrane, virus, bacterium, eukaryotic cell.

Which of the following features are present in mitochondria but not in chloroplasts? I. DNA and ribosomes II. Outer and inner membranes III. Cristae

Cristae

During endocytosis, what change will most likely occur in the plasma membrane of a cell?

Decreases in size; portion of membrane pinches off to enclose macromolecules and make vesicle.

In what way are eukaryotic chromosomes different from prokaryotic chromosomes?

Eukaryotic chromosomes (histones): located in membrane, protein is present, and there are multiple chromosomes. Prokaryotic chromosomes (ring shape): located in cytoplasm and protein is absent

Which pair of characteristics are correct for the cellular processes of exocytosis and endocytosis?

Exocytosis: secretion of cellular materials Endocytosis: vesicles are moved away from the plasma membrane.

Which organelles have a transport function?

Golgi apparatus, ER, and vesicles.

What describes the functions of the following organelles: Golgi apparatus and Rough ER?

Golgi apparatus: processing of protein (synthesis, packaging, and releases). Rough ER: synthesis of protein for cell secretion (transportation and protein development).

Which statements are characteristics of diffusion through membranes? I. Polysaccharides can be transported. II. It can be facilitated by special channels. III. It is affected by concentration gradients.

II and III only

Which of the following is a feature of exocytosis but not endocytosis?

In exocytosis, membrane becomes larger because substances leave cell while endocytosis has substances entering cell (making membrane smaller).

Which of the following structures are present in both plant and animal cells? I. Cell wall II. Chloroplast III. Mitochondrion

Mitochondrion

The key below can be used to identify some of the structures in the cytoplasm of liver cells. Which structures are ribosomes? 1. Enclosed in membrane Not enclosed in a membrane 3. Composed of one globular structure Composed of two sub-units

Not enclosed in a membrane Composed of two sub-units

Which pair of features is correct for both plant and prokaryotic cells?

Plant cell: contains DNA associated with protein Prokaryotic cell: contains naked DNA

In viewing an electron micrograph of a cell, ribosomes, pili and a single circular chromosome are observed. What other structure is likely to be present?

Prokaryotic cell: cell wall, plasmid, cytoplasm, flagella, and etc.

What is facilitated diffusion?

The passive movement of a particle across a cell membrane via a channel protein.

What are organelles?

Tiny organs in cells that carry out a specific function

Which combination of organelles is found in most plant and animal cells?

all organelles are present in both types of cells except for large central vacuole, cell wall and chloroplasts found in plant cell (ex: mitochondria, cytoplasm, and ribosomes).

What is essential for diffusion?

change in concentration gradient

Which of the following is required for osmosis to occur?

concentration gradient and semi-permeable membrane.

Which of the following is a characteristic of organelles?

found in both eukaryotic and prokaryotic cells (membrane-bound organelles are only found in eukaryotes)

Which of the following could be a function of a membrane protein?

hormone binding sites; enzymatic action; cell adhesion; cell to cell communication; channels for passive transport; pumps for active transport; marker.

Which two molecules are the principal components of membranes?

proteins and lipids

Which ratio limits the size of cells?

surface area to volume