BIOLOGY IB

• A

• B

• C

• D

Erythrocytes (red blood cells) have a diameter of 7000 nm. Pancreatic cells have a diameter of 35 um.

• The erythrocytes are 5 times smaller.

• The erythrocytes are 50 times smaller.

• The erythrocytes are 5 times larger.

• The erythrocytes are 50 times larger.

Which of the following is not a correct description of a light microscope or an electron microscope?

• An electron microscope can resolve specimens as small as 0.5 nm in diameter.

• A light microscope has a maximum resolution of 0.2 um.

• A light microscope has a maximum resolution of 0.05 um.

• An electron microscope can resolve specimens as small as 200 nm in diameter.

Which of the following is evidence for the endosymbiotic theory?

• 70s ribosomes can be found in prokaryotic cells.

• Mitochondria contain their own DNA.

• Meteorites have been found that contain organic molecules.

• In certain cases, gene transfer from prokaryotic cells to eukaryotic cells via plasmids has been found to oocur.

Membrane-bound sacs containing products of metabolism are produced by the endoplasmic reticulum. Where are these products used?

• Inside lysosomes only

• Outside the cell only

• Inside the cell only

• Inside and outside the cell

The Davson - Danielli model of cell membrane structure stated that cell membranes consisted of a phospholipid bilayer sandwiched between two layers of protein. Which piece of evidence contributed to the falsification of the Davson - Danielli model and the acceptance of the Singer - Nicolson fluid mosaic model?

• The presence and positioning of globular peripheral and integral proteins.

• The amphipathic properties of phospholipids.

• The presence of a hydrophobic region on the surface of the membrane.

• The orientation of the hydrophobic phospholipid tails away from the proteins.

What is the difference between simple diffusion and facilitated diffusion?

• A

• B

• C

• D

Which of the following does not happen in an animal cell division?

I. DNA is transcribed and translated.

II. Spindle is formed from microtubules.

III. Cell plate forms to divide daughter cells

IV. Plasma membrane pulled inwards around cell equator to form cleavage furrow.

• III only

• I and III only

• II only

• IV only

Each of the following events takes place during mitosis.

1. Chromosomes uncoil.

2. Chromatids move to opposite poles of the cell.

3. Centromeres divide.

4. Chromosomes line up along the equator of the spindle.

5. Two chromatids are joined by a centromere.

• A

• B

• C

• D

Which property of carbon makes it a good basis for organic molecules?

• It exists in hard and stable forms like graphite and diamond.

• It forms a varying number of covalent bonds to other atoms.

• It can form millions of different compounds in association with hydrogen and oxygen.

• It forms strong, ionic bonds with other atoms.