UIL Texas Questions

Examine all of the answer choices below. Which choice is the most inclusive (e.g. the grouping that would include all of the others)?

• Class

• Genus

• Family

• Species

• Order

Answer explanation

Level 1 •

Biological hierarchy •

King Phillip Came Over For Great Spaghetti •

Kingdom

Phylum

Class

Order

Family

Genus

Species

Examine the image of a transmembrane protein embedded within a biological membrane. What can you predict about the area indicated by the arrow?

• The amino acids are mostly hydrophilic.

• The amino acids are mostly hydrophobic.

• The indicated area could easily move between the current embedded state and the extracellular or intracellular environment.

• The indicated structure is a fatty acid.

• The embedded portions of the protein would be covalently bonded to adjacent phospholipids.

Answer explanation

Level 3

• Membrane and organic molecule structure/function

A population in Hardy-Weinberg equilibrium contains a total of 6992 individuals. Out of the total, 724 exhibit the dominant phenotype. What is the frequency of the recessive allele in this population?

• 0.0532

• 0.1035

• 0.3218

• 0.8965

• 0.9468

Answer explanation

• -Level 2, population genetics 1.

-Look for wording that helps find q or q2 “Out of the total, 724 exhibit the dominant phenotype.”

-Therefore, the remaining must have recessive phenotype and be homozygous recessive 6992 – 724 = 6268

2. Determine the frequency of homozygous recessive (q2). 6268/6992 = 0.8965

3. Solve for the “frequency of the recessive allele” (q) q2= 0.8965 q = √0.8965 = 0.9468 S

Tags

NGSS.HS-LS4-2

NGSS.HS-LS4-3

For the reaction

3NO₂ + H₂O --> 2HNO₃ + NO

What is the maximum amount of HNO₃ which could be formed from 184 g of NO₂ and 27 g of H₂O?

• 126. g

• 211. 211. g

• 94.5 g

• 25.3 g

• 168. g

Answer explanation

Limiting Reactant Problem:

Find the limiting reactant first, then get the answer:

184/46 = 4 mol NO2

which needs 4/3 = 1.33 mol H2O 27/18 = 1.5 mol H2O which is too much (excess) base answer on the limiting amount – the NO2

4 x (2/3) = 8/3 mol of HNO3 produced

8/3 (63) = 168 g HNO3

Tags

NGSS.HS-PS1-7

Which of the following liquids has the highest vapor pressure?

• H₂O

• C₅H₁₂

• C₂H₅OH

• C₁₀H₁₂

Answer explanation

The liquid with the fewest/weakest intermolecular forces (imfs) will have the highest vapor pressure. •Small imfs mean faster/easier vaporization rates and higher vapor pressures.

• Water and ethanol both have relatively strong imfs (H-bonding) and therefore have relatively low vapor pressures.

• Pentane and decane both only have dispersion forces which are very weak.

• Overall imf strength scales with molecular size – so decane has stronger imfs than pentane.

• So pentane will have the highest vapor pressure.

The heat of combustion (∆H°) for propane is 2220 kJ/mol. How many kJ of energy are released when 5.00 L of propane at 2.45 atm and 25°C is burned?

• 1110 kJ

• 2220 kJ

• 1875 kJ

• 555 kJ

• 3330 kJ

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-1

A hockey puck with a mass of 150.0 g slides horizontally across ice. The initial velocity of the puck is 13.0 m/s. If the puck comes to a stop after sliding 47.0 m, what is the coefficient of friction between the puck and the ice?

• 0.0570

• 0.0920

• 0.180

• 0.270

• 0.370

Tags

NGSS.HS-PS2-1