ECOLOGY
A scientist measures the number of fish in a pond each year. The fish population remains relatively stable for five years despite small fluctuations.
This stability is most likely due to:
Carrying Capacity
A DNA strand contains the base sequence:
A-T-G-C-C-A
What would be the complementary DNA strand?
T-A-C-G-G-T
During exercise, a person's breathing rate increases.
What is the purpose of this response?
To provide more oxygen and remove more carbon dioxide.
A population contains variation in fur color.
Which characteristic makes natural selection possible?
Genetic variation
A cell contains 46 chromosomes before division.
How many chromosomes will each daughter cell contain after mitosis?
46
Which organelle contains the genetic information that controls cell activities?
Nucleus
Grass → Rabbit → Fox
What is the primary source of energy for this food chain?
The Sun
A scientist exposes bacteria to ultraviolet light and notices changes in DNA sequences.
What process most likely occurred?
Mutation
Students place enzyme solutions in water baths at different temperatures and measure reaction rates.
What is the dependent variable?
Reaction rate
Scientists compare DNA sequences of several species.
Why is DNA considered strong evidence of evolutionary relationships?
Species with more similar DNA are likely more closely related.
A cell undergoes meiosis.
How many chromosomes will be found in each resulting gamete?
23
Students place plant cells in darkness for several days.
Which process will decrease the most?
Photosynthesis
A population of deer grows too large and begins to run out of food. What will most likely happen to the population?
It will Decrease
If a heterozygous tall plant (Tt) is crossed with a heterozygous tall plant (Tt), what is the probability of producing a short plant?
25%
A student notices that enzyme activity decreases sharply after exposure to very high temperatures.
What most likely happened to the enzyme?
It became denatured.
A drought causes plants with deeper roots to survive better than plants with shallow roots.
Which process is occurring?
Natural Selection
Why does meiosis increase genetic variation?
It produces gametes with different combinations of genes.
A scientist removes ribosomes from a cell.
Which cellular process would be directly affected?
Protein synthesis
Students investigate the effect of fertilizer runoff on algae growth in a pond.
Independent Variable: Amount of fertilizer
Dependent Variable: ?
Algae growth
Researchers insert a gene for drought resistance into a crop plant.
What technology was most likely used?
Genetic Engineering
After eating a meal, blood glucose levels increase.
Which hormone helps return blood glucose levels to normal?
Insulin
A group of birds becomes geographically isolated from the original population for thousands of years.
What may eventually result from this isolation?
Speciation
Which process restores the chromosome number from 23 to 46?
Fertilization
An experiment compares photosynthesis rates in plants exposed to different light intensities.
What is the independent variable?
Light intensity
An abandoned farm is left untouched for 50 years. The area changes from grasses to shrubs to a mature forest.
Explain why the types of organisms present changed over time.
Ecological Succession
Changes in environmental conditions allowed different species better adapted to the new conditions to survive and reproduce
Scientists insert a human insulin gene into bacteria so the bacteria produce insulin. This process is called:
Genetic Engineering
A person has damage to the alveoli in their lungs.
Explain how this damage would affect the circulatory system.
Less oxygen would enter the blood, reducing oxygen transport throughout the body.
Scientists discover two species that have nearly identical bone structures but different functions.
These structures provide evidence of:
Common ancestry (homologous structures)
A developing embryo is exposed to a harmful chemical during early development.
Why could this exposure have serious effects?
Cells are rapidly dividing and differentiating into tissues and organs.
A student observes the following sequence:
Cell → Tissue → Organ → Organ System → Organism
Explain why this sequence is important in multicellular organisms.
Specialized cells work together to form tissues, organs, and organ systems that carry out life functions.