Genes & DNA
Meiosis, Variation & Inheritance
Evolution & Natural Selection
Feedback & Body Systems
EntEcology, Energy Flow & Biodiversity
100
A student models a protein and bends one section incorrectly. The model no longer fits into the enzyme’s active site. This demonstrates that function depends on this.
What is protein shape?
100
A cell with 46 chromosomes undergoes meiosis. Each resulting gamete contains this number.
What is 23?
100
A bird population develops longer beaks after a drought reduces available food sources. The longer beaks represent this.
What is an adaptation?
100
When CO₂ levels rise, breathing rate increases to remove excess CO₂. This is an example of this type of feedback.
What is negative feedback?
100
Only about 10% of energy is passed to the next trophic level because most energy is lost as this.
What is heat?
200
A plant grown in full sunlight produces thick, waxy leaves, while genetically identical plants grown indoors do not. This difference is due to a change in this process.
What is gene expression?
200
A data table shows offspring with new combinations of traits not found in either parent. This pattern is evidence that this process occurred during meiosis.
What is crossing over?
200
DNA analysis shows two species differ by only three base pairs, while a third species differs by 40. This suggests the first two species have this relationship.
What is they are more closely related?
200
The digestive system breaks down food, and this system transports nutrients to cells.
What is the circulatory system?
200
A population graph levels off after rapid growth. The flat portion represents this ecological limit.
What is carrying capacity?
300
A mutation occurs in DNA, but the cell still produces a normal protein because the mRNA codon still codes for the same amino acid. This is an example of this type of mutation.
What is a silent mutation?
300
A plant with yellow round seeds is crossed with a plant with green wrinkled seeds. Some offspring have yellow wrinkled seeds, a combination not seen in either parent. This happens because the two traits are sorted this way during meiosis.
What is independently?
300
On a cladogram (evolutionary tree), Species A and B share a derived trait not found in Species C. This indicates A and B share this.
What is a more recent common ancestor?
300
After recovering from a viral infection, memory cells remain. Their presence allows this to happen if the virus returns.
What is a faster immune response?
300
A non‑native plant spreads rapidly and reduces native plant populations. This type of organism is known as this.
What is an invasive species?
400
A student examines a diagram showing many alveoli working together inside the lung to perform gas exchange. Each alveolus is made of thin layers of cells, but the entire group of alveoli functions as part of a larger structure that carries out breathing. At which level of biological organization does the lung belong?
What is an organ?
400
A doctor finds that a developing embryo has 47 chromosomes instead of 46. This happened because the chromosomes did not separate correctly during meiosis.
What is nondisjunction?
400
A population of beetles becomes darker after a forest fire darkens the environment. The fire acts as this.
What is selective pressure?
400
A hormone affects only certain cells because those cells contain these matching structures.
What are receptors?
400
An ecosystem with many species is more likely to maintain this long‑term condition.
What is stability?
500
A diagram shows: (1) a group of similar cells, (2) an entire organism, (3) a single cell, (4) several organs working together, (5) one organ. Students are asked to place these in order from smallest level of organization to largest. What is the correct order?
What is: cell → tissue → organ → organ system → organism?
500
A Punnett square shows the cross Tt × Tt for plant height (T=tall, t=short). These different combinations of alleles appear because each parent passes on only one allele for the trait. This happens because of this process during meiosis. What are the possible phenotypes along with their probability for occurring?
Tall (TT or Tt) → 3 out of 4 → 75%
Short (tt) → 1 out of 4 → 25%
500
A river forms between two populations of squirrels. After many generations, they can no longer interbreed. This outcome is known as this.
What is speciation?
500
A person loses the ability to regulate water balance due to kidney damage. This internal condition is disrupted.
What is homeostasis?
500
Removing one predator causes prey populations to explode and plant populations to collapse. This predator was acting as this.
What is a keystone species?