Many mouse genes are “tissue-specific,” that is, they are present throughout the body but are expressed in only one of the animal’s many tissue types. (Other mouse genes are expressed throughout the body, or in multiple tissues.) Geneticists can study the regulation of a mouse gene by fusing the gene’s promoter region to the LacZ coding sequence and injecting the construct to create a transgenic mouse. Fusion of the mouse amylase promoter to LacZ yielded a Pamylase-LacZ construct.

You are surprised to observe that mice homozygous for the transgene insertion display a serious heart defect. (Heterozygotes have normal hearts.) which one is a  possible explanation?

a) LacZ overexpression (with two copies of the transgene) causes the defect.

b) the insertion disrupted a gene that is haploinsufficient.

c) the insertion disrupted a gene that is haplosufficient.

d) LacZ expression inhibition (with two copies of the transgene) causes the defect.

Which of the following statements is correct  predict about the  heart defect?

#Question id: 389

#Unit 1. Structure and Function of Biomolecules

A weak acid HA has a pKa of 5.0.  If 1.0 mol of this acid and 0.1 mol of NaOH were dissolved in one liter of water, what would the final pH be?

#Question id: 390

#Unit 1. Structure and Function of Biomolecules

What are the properties arising due to varying concentrations of solute in a given solvent, irrespective of the nature of solute with respect to the solvent?

#Question id: 391

#Unit 1. Structure and Function of Biomolecules

In a hospital laboratory, a 10.0 mL sample of gastric juice, obtained several hours after a meal, was titrated with 0.1 M NaOH to neutrality; 7.2 mL of NaOH was required. The patient’s stomach contained no ingested food or drink, thus assume that no buffers were present. What was the pH of the gastric juice?

#Question id: 392

#Unit 1. Structure and Function of Biomolecules

When an ionic compound such as sodium chloride (NaCl) is placed in water, the component atoms of the NaCl crystal dissociate into individual sodium ions (Na+) and chloride ions (Cl-). In contrast, the atoms of covalently bonded molecules (e.g., glucose, sucrose, glycerol) do not generally dissociate when placed in aqueous solution. Which of the following solutions would be expected to contain the greatest number of solute particles (molecules or ions)?

#Question id: 393

#Unit 1. Structure and Function of Biomolecules

Carbon dioxide (CO2) is readily soluble in water, according to the equation CO2 + H2O ↔ H2CO3. Carbonic acid (H2CO3) is a weak acid. If CO2 is bubbled into a beaker containing pure, freshly distilled water, which of the following graphs correctly describes the results?

#Question id: 394

#Unit 1. Structure and Function of Biomolecules

What will be the H+ ion concentration in a solution prepared by mixing 50.0 mL of 0.20 M NaCl, 25 mL of 0.10M NaOH and 25.0 mL of 0.30M HCl?