Crosscutting: Patterns Flashcards

The periodic table of elements arranges elements in rows and columns. What pattern of properties is generally observed when moving from left to right across a row (a period)?

Answer: Elements change from metals to nonmetals.

A fundamental pattern in the periodic table is the transition of properties across a period. Elements on the far left are typically reactive metals, followed by less reactive metals, metalloids, and finally nonmetals and noble gases on the right.

A graph of global average temperatures from 1880 to the present day shows small, cyclical increases and decreases from year to year, but an overall increasing trend over the entire period. This suggests that:

Answer: Both short-term cycles and a long-term trend are occurring simultaneously.

Recognizing patterns often involves seeing both smaller, repeating cycles (like annual variation) and a larger, overarching trend (like long-term climate change). The data described shows a pattern of natural, short-term variability superimposed on a long-term warming trend.

In a food web diagram, arrows point from the organism being eaten to the organism that eats it. If you observe a pattern of many different arrows all pointing toward a single species, what does this indicate about that species' role?

Answer: It is prey for many different predators.

The pattern of arrows indicates the flow of energy. If many arrows point *to* a species, it means many different species are consuming it, making it a common source of food, or prey, for many predators in the ecosystem.

Fossils of a specific, non-swimming, land-dwelling reptile are found in rock layers of the same age in both South America and Africa. What large-scale pattern in Earth's history does this evidence support?

Answer: The theory of continental drift.

The pattern of finding identical, non-mobile species' fossils on continents now separated by vast oceans is key evidence for the theory of continental drift. It suggests these landmasses were once connected in a single supercontinent (Pangaea).

The phases of the Moon (New, Crescent, Quarter, Gibbous, Full) repeat in a predictable 29.5-day cycle. This observed pattern is primarily caused by:

Answer: The changing position of the Moon in its orbit around the Earth.

The lunar phases we see are a pattern created by the changing angles at which we view the Moon's sunlit surface as it orbits the Earth. The cycle is a direct result of this orbital motion relative to the Sun and Earth.

In a healthy ecosystem, the population sizes of predators and their prey often show a cyclical pattern where an increase in the prey population is followed by an increase in the predator population. What typically happens next in this pattern?

Answer: The prey population decreases, followed by a decrease in the predator population.

The increase in predators leads to more prey being eaten, causing the prey population to decline due to increased predation. With less food (prey) available, the predator population then also declines, continuing the cycle.

All known living organisms, from bacteria to humans, use DNA and the same basic genetic code to store and transmit hereditary information. This universal pattern is strong evidence for:

Answer: The idea that all life shares a common ancestor.

The fact that such a complex and specific system like the genetic code is shared across all known life forms is a powerful pattern. It strongly suggests that all life evolved from a single origin, or a common ancestor that possessed this system.