Cell Biology and Bio molecules Worksheet

Name the type of bond that joins the two monosaccharides in lactose.

• Glycosidic bond

• Peptide bond

• Hydrogen bond

• Ionic bond

Name the type of reaction that breaks this bond.

• Hydrolysis

• Condensation

• Oxidation

• Reduction

The structure of cellulose is:

• a linear polymer of β-glucose units linked by β-1,4-glycosidic bonds

• a branched polymer of α-glucose units linked by α-1,6-glycosidic bonds

• a linear polymer of α-glucose units linked by α-1,4-glycosidic bonds

• a branched polymer of β-glucose units linked by β-1,6-glycosidic bonds

Fig. 3.1 is a transmission electron micrograph showing two adjacent cells in a leaf. Which feature visible in Fig. 3.1, other than the cell wall, identifies the cells as plant cells?

• Chloroplasts

• Centrioles

• Flagella

• Glycogen granules

Hydrogen bonding between water molecules occurs when:

• a hydrogen atom in one water molecule is attracted to the oxygen atom in another water molecule.

• a hydrogen atom in one water molecule is attracted to the hydrogen atom in another water molecule.

• an oxygen atom in one water molecule is attracted to the oxygen atom in another water molecule.

• a hydrogen atom in one water molecule forms a covalent bond with the oxygen atom in another water molecule.

Water is an excellent solvent for ions because:

• it is a polar molecule that can surround and separate ions.

• it is non-polar and does not interact with ions.

• it forms covalent bonds with ions.

• it repels both positive and negative ions.

Fig. 4.1 is a photomicrograph of a cross-section of a tubular structure in the kidney made from epithelial cells. The actual length of epithelial cell A along the line P–Q is 35 μm. Calculate the magnification of the image shown in Fig. 4.1. Write down the formula and use it to make your calculation. Show your working.

• Formula: magnification = image size / actual size. Magnification = (measured length of P–Q in the image) / 35 μm. (The exact magnification value depends on the measured image length, which is not provided in the image.)

• Formula: magnification = actual size / image size. Magnification = 35 μm / (measured length of P–Q in the image).

• Formula: magnification = image size × actual size. Magnification = (measured length of P–Q in the image) × 35 μm.

• Formula: magnification = image size + actual size. Magnification = (measured length of P–Q in the image) + 35 μm.

Which two features could be added to the labels in Fig. 5.1 to confirm that the cell is prokaryotic and not eukaryotic?

• Presence of a nucleoid and absence of membrane-bound organelles

• Presence of a nucleus and mitochondria

• Presence of chloroplasts and large central vacuole

• Presence of multiple linear chromosomes and endoplasmic reticulum

Complete Table 5.1: Does a DNA nucleotide with adenine contain nitrogen?

• Yes

• No

• Only in RNA

• Only in cytosine

Complete Table 5.1: Does an RNA nucleotide with adenine contain nitrogen?

• Yes

• No

• Only in DNA

• Only in proteins