BIOL 464 Exam 1

Which of the following processes is associated with Milankovitch cycles?

Gradual shifts in the eccentricity of the planet as it rotates around the sun.

Plants preferentially take up ¹²C over ¹³C during photosynthesis. Fossil fuels are derived from ancient plant material, and their combustion has added large amounts of carbon to the atmosphere since the Industrial Revolution. Based on this information, what change would you expect in the atmospheric ¹³C/¹²C ratio?

The ¹³C/¹²C ratio should decrease because fossil-fuel carbon is relatively enriched in ¹²C.

A linear regression is fit to predict body mass from body length. Some individuals have positive residuals and others have negative residuals. Which statement best describes these residuals and how they are used to fit the regression line?

Positive residuals occur when observed values are above the predicted line and negative residuals occur when observed values are below it; the regression line is chosen to minimize the squared residuals.

Which of the following statements below is true about oxygen isotopes?

O¹⁶ tends to more readily evaporate into the air because it is lighter.

Which group of factors are associated with external factors that influence Earth's climate?

Earth's orbit, solar radiation, and axial tilt

Based on the figure below, which statement is true?

population 1 is more variable and has a higher mean than population 2

Based on the figure below, prior to 1960, solar radiation and air temperature were ______ correlated, and after 1960, they were _______ correlated.

positively, negatively

A researcher wants to test whether fertilizer increases plant growth. Plants in the fertilizer treatment are placed next to a sunny window, while plants in the no-fertilizer treatment are placed on the other side of the room, where they receive less sunlight. After four weeks, plants receiving fertilizer are taller. What is the primary problem with interpreting these results?

Sunlight is a confounding variable

Which of the following statements best distinguishes between weather and climate?

Weather refers to short-term atmospheric conditions, such as daily temperature and rainfall, while climate describes the long-term average of these conditions over decades or centuries.

Which group of factors are associated with internal factors that influence Earth's climate?

Plate tectonics, volcanic activity, and ocean circulation

Which process allows scientists to use oxygen isotopes in ice cores to estimate past temperatures?

During colder conditions, proportionally less ¹⁸O evaporates from the ocean and reaches the poles, so polar snowfall contains less ¹⁸O relative to ¹⁶O.

Milankovitch cycles

describe the collective effects of changes in the Earth's orbit and axial tilt that influence long-term climate patterns, particularly the timing of glacial and interglacial periods over tens of thousands to hundreds of thousands of years

Researchers find that regions with high greenhouse gas emissions are experiencing faster warming compared to regions with lower emissions. However, within regions with high emissions, those that also experience frequent volcanic activity show slower warming compared to regions without volcanic activity. This can be mostly explained by:

An interaction in which volcanic activity injects particles into the atmosphere that reflect sunlight, causing a temporary cooling effect that offsets some of the warming from greenhouse gases.

The t-statistic measures?

How large the difference between the two means is relative to the variation in the data. Larger absolute values indicate stronger evidence of a difference.

The p-value is?

the probability of observing a difference this large or larger if the two population means are actually equal. A small p-value indicates evidence against equal means.

Closest ancestor to homo sabiens?

Homo neanderthalensis