Bio Midterm Review Spring 2025

Salivary amylase is an enzyme that aids in the breakdown of starch into sugars. The effect of temperature on amylase activity is shown.

Which statement best explains why the reaction rate decreases when the temperature increases above 38* Celsius?

• The shape of the enzyme's active site changes.

• The amino acid sequence of the enzyme changes.

• The concentration of the enzyme increases.

• The number of enzyme-substrate collisions increases.

Spores of the fungus Ustilago maydis land and grow on sweet corn. The fungus then infects the plant tissue, extracting nutrients from the plant's cells.

 

The relationship between sweet corn and Ustilago maydis can best be described as —

• competition

• parasitism

• commensalism

• predation

A student is drawing an energy pyramid.

How does the amount of energy available at each level of the pyramid change from the bottom to the top?

• The amount of energy remains the same at each level.

• The amount of energy changes randomly at each level.

• The amount of energy decreases by 10% at each level from the bottom to the top.

• The amount of energy increases by 10% at each level from the bottom to the top.

Scientists can use the fossil record to determine changes in an environment. What does the abrupt appearance of new organisms show?

The abrupt appearance of new organism is evidence of _________  and ________.

• traditional fossils

• stasis

• increase in biodiversity

• an unstable environment

• gradualism

Which statement accurately compares eukaryotic cells and prokaryotic cells?

• Only prokaryotic cells lack outer membranes and cell walls.

• Only prokaryotic cells have membrane-bound organelles.

• Eukaryotic cells replicate faster than prokaryotic cells.

• Eukaryotic cells are more complex than prokaryotic cells.

Malaria is a blood disease caused by a parasite carried by mosquitoes. Some populations of mosquitoes have become resistant to two insecticides often used to kill them. Scientists have discovered that these mosquitoes have a gene mutation that makes them able to break down the insecticides into a harmless substance.

Which statement about the effect of the mutation on the mosquito populations best explains the relationship between natural selection and this mutation?

• Mosquitoes with the mutation are better able to survive and produce offspring.

• Mosquitoes without the mutation are able to move to other locations to avoid the effects of the insecticides.

• Mosquitoes are able to adapt by mutating to resist the insecticides.

• Mosquitoes with the mutation are more likely to carry the parasite that causes malaria.

A student feels stress and anxiety after seeing a traffic accident. Immediately, an increased heart rate and extra energy with the release of adrenaline is felt. Which of the following systems of the body are working together? _{(TEKS 10.A)}

• Nervous and Muscular

• Reproductive and Skeletal

• Skeletal and Endocrine

• Nervous and Endocrine

An important group of proteins includes enzymes. Enzymes are known as biological catalysts because they ----- 

• change the state of matter between solids, liquids, and gases

• speed up the rates of chemical reactions

• cause one element to change into a different element

• allow all chemical reactions to proceed under the same conditions

A student is drawing an energy pyramid. What is the original source of all energy for the energy pyramid?

• Nuclear reactions
• Geothermal energy
• The sun
• The moon

In a Central Texas grassland, the producers incorporate 12,000 kJ of energy from the sun into their tissues. About how much energy would be incorporated into the tissues of herbivores?

• 1200 kJ
• 120 kJ

• 120000 kJ

• 12 kJ