Inferences
Researchers notice that a species of fish living near a factory has developed unusually high levels of a toxin in its tissues, even though the toxin is barely detectable in the surrounding water. What can you infer?
The fish are accumulating the toxin in their bodies over time, likely through bioaccumulation or their food sources.
A lake experiences several weeks of unusually high temperatures. Warmer water holds less dissolved oxygen. Predict what may happen to organisms that require high oxygen levels.
Their populations may decline, move to cooler areas, or experience increased mortality because less oxygen is available.
A student tests whether fertilizer affects plant height.
After four weeks:
No fertilizer: average growth = 8 cm
Low fertilizer: average growth = 14 cm
Moderate fertilizer: average growth = 21 cm
High fertilizer: average growth = 13 cm
What conclusion is best supported?
Moderate fertilizer produced the greatest growth; increasing fertilizer beyond that amount did not improve growth and may have reduced it.
Identify and interpret the figurative language:
“The hurricane devoured everything in its path.”
Personification/Metaphorical language — The hurricane caused enormous destruction as it moved through the area; it did not literally eat anything.
The prefix bio- means “life,” and -logy means “the study of.”
Using the word parts, what does biology literally mean?
The study of life.
Two genetically identical plants receive equal amounts of water, nutrients, and light. One is kept at 22°C and grows normally. The other is kept at 5°C and grows very slowly. What can reasonably be inferred?
Temperature affects the plants' growth or biological processes, since the other major variables were controlled.
A bacterial population is repeatedly exposed to an antibiotic. A few bacteria possess mutations that make them resistant. Predict what will happen if the same antibiotic continues to be used.
Resistant bacteria will survive and reproduce, causing antibiotic resistance to become increasingly common in the population.
Researchers measure reaction time after different amounts of sleep:
8 hours: 240 milliseconds
6 hours: 275 milliseconds
4 hours: 340 milliseconds
What conclusion is supported by the data?
In this study, less sleep was associated with slower reaction times.
A science writer states:
“DNA is the instruction manual tucked inside nearly every cell.”
What does this metaphor communicate?
DNA contains biological information or instructions that cells use for development, functioning, and reproduction.
The prefix endo- means “within/inside,” while exo- means “outside.”
Based on these prefixes, what is the basic difference between an endoskeleton and an exoskeleton?
An endoskeleton is an internal skeleton, while an exoskeleton is an external skeleton.
After wolves disappear from an ecosystem, researchers observe an increase in deer, a decline in young trees, and increased erosion along streams. What can you infer about the wolves' former role?
The wolves indirectly helped maintain vegetation and stream stability by controlling the deer population.
A region removes large areas of vegetation while annual rainfall remains unchanged. Predict a likely effect during periods of heavy rainfall.
Runoff, soil erosion, and possibly flooding will increase because fewer plant roots and leaves are available to slow and absorb water.
A researcher concludes, “Drinking caffeine causes students to earn higher grades” after discovering that students who regularly consume caffeine have slightly higher GPAs.
What is wrong with this conclusion?
The data show a correlation, not causation. Other variables could explain the difference in GPA.
Explain the meaning of:
“The discovery sent shock waves through the scientific community.”
The discovery caused widespread surprise, concern, excitement, or reaction among scientists. No literal shock waves occurred.
Break apart the word photosynthesis using these clues:
photo- = light
syn- = together
-thesis = putting/placing
Based on the word parts, what does the term suggest?
“Putting together with light” — organisms use light energy to build or produce substances such as glucose.
Scientists discover fossils of the same extinct freshwater organism in rock formations on two continents now separated by thousands of miles of ocean. The organism could not have survived in saltwater. What can you infer?
The continents were likely connected or geographically much closer when the organisms were alive.
Ocean water absorbs increasing amounts of atmospheric carbon dioxide, lowering its pH. An organism depends on calcium carbonate to construct its shell. Predict a likely long-term effect.
The organism may have increasing difficulty forming or maintaining its shell, potentially causing its population to decline.
Scientists test a medication on 2,000 participants. The treatment group improves significantly more than the placebo group. However, all participants are adults ages 20–35.
Which conclusion is NOT justified?
That the medication will be equally effective for children, teenagers, or older adults. Those populations were not studied.
A researcher writes:
“The evidence whispered at first, but after the final experiment, it was shouting.”
What does this mean?
Early evidence weakly suggested a conclusion, but additional experimental results made the evidence much stronger and more convincing.
Type: Personification/extended metaphor
A scientist describes an organism as microscopic.
Use the morphemes:
micro- = small
-scopic = relating to viewing or examining
What can you determine about the organism?
It is extremely small and generally requires magnification or a microscope to be clearly viewed.
A disease becomes increasingly common in a population after an environmental change. Researchers discover that individuals with one particular genetic variant are significantly less likely to develop severe disease, although the variant was previously uncommon. What can you infer may happen to the frequency of this variant over many generations?
The variant may become more common because individuals carrying it have a survival or reproductive advantage, causing natural selection to favor it.
A predator normally consumes Species A. Species A consumes Species B, and Species B competes with Species C for the same limited resource. The predator population suddenly declines. Predict how A, B, and C may change.
Species A will likely increase, causing Species B to decrease from increased predation. With fewer Species B competing for the resource, Species C may increase.
Researchers observe that cities with more trees tend to have lower summer temperatures. They conclude that planting trees will always reduce a city's temperature by exactly 5°C.
Why does the evidence fail to support the full conclusion?
The evidence supports an association between greater tree coverage and lower temperatures, but it does not establish a universal cause-and-effect relationship or support the specific claim of an exact 5°C reduction.
A science journalist writes:
“Antibiotics were once a fortress against bacterial infection, but evolution has been quietly picking the locks.”
Explain the extended metaphor.
Antibiotics once provided strong protection against bacterial infections, but bacteria have gradually evolved resistance, making some antibiotics less effective. The “fortress” represents protection and “picking the locks” represents bacteria overcoming that protection.
Without being given the definition, analyze the word biodegradable:
bio- = life
de- = down/apart
grad = step/change
-able = capable of
What does biodegradable most likely mean?
Capable of being broken down naturally by living organisms or biological processes.