Mid-ocean ridges
Rift valleys
Volcanic island arcs
Answer 1
At an oceanic-oceanic convergent boundary, one plate subducts under the other. This creates a trench at the subduction zone and magma rises to form a chain of volcanic islands.
Day 7
TEKS 8.9(A)
Part A
Alfred Wegener proposed the Theory of Continental Drift. Which piece of evidence supports the idea that the continents were once joined together?
Matching fossils on distant continents.
Satellite images showing crustal movement.
Part B
What mechanism was later discovered to explain how the plates actually move?
Convection currents in the mantle.
Tidal forces from the moon.
Answer 2
Part A: Matching fossils
Part B: Convection currents
Wegener used fossils, rock types, and the "jigsaw fit" as evidence. However, he couldn't explain the force. We now know that heat transfer (convection) in the asthenosphere moves the tectonic plates.
Day 7
TEKS 8.9(B)
Describe the movement of tectonic plates at a transform boundary and name one major geologic event that occurs there.
Answer 3
At a transform boundary, two plates slide past each other horizontally. This movement often results in earthquakes due to built-up friction and tension being suddenly released.
Day 8
TEKS 8.9(C)
A topographic map shows contour lines that are very close together. What can you conclude about this area?
Select TWO correct answers.
The elevation is changing rapidly.
The terrain is very flat.
The slope of the land is very steep.
The elevation is constant.
Answer 1
Contour lines connect points of equal elevation. When lines are close together, it means you are gaining or losing height in a short horizontal distance (steep).
Day 8
TEKS 8.9(C)
Part A
A satellite image taken in 1990 shows a large forest. An image from 2020 shows a shopping mall in the same location. What process occurred?
Natural Erosion
Human Modification
Part B
Which of the following is a likely environmental consequence of this change?
Increased runoff and potential for flooding.
Increased biodiversity in the area.
Answer 2
Part A: Human Modification
Part B: Increased runoff/flooding
Replacing soil and trees with concrete (pavement) prevents water from soaking into the ground, leading to higher levels of surface runoff.
Day 8
TEKS 8.9(C)
Explain the difference between weathering and erosion in the context of a river carving a canyon.
Answer 3
Weathering is the breaking down of rock into smaller pieces (sediment).
Erosion is the movement of that sediment to a new location (by the river water).
Day 9
TEKS 8.7(A)
Which of the following factors contribute to the change of seasons on Earth?
Select TWO correct answers.
The distance between the Earth and the Sun.
The tilt of the Earth on its axis.
The revolution of the Earth around the Sun.
The rotation of the Earth on its axis.
Answer 1
Seasons are caused by the angle of sunlight. Because of the tilt, as Earth revolves, different hemispheres receive more direct or indirect sunlight. Distance DOES NOT cause seasons.
Day 9
TEKS 8.7(A)
Part A
If the Northern Hemisphere is tilted away from the sun, what season is occurring in Texas?
Summer
Winter
Part B
Which statement best describes the daylight hours during this time?
The daylight hours are longer than the nighttime hours.
The daylight hours are shorter than the nighttime hours.
Answer 2
Part A: Winter
Part B: Shorter daylight hours
Tilted Away = Indirect Sunlight = Winter = Shorter Days.
Tilted Toward = Direct Sunlight = Summer = Longer Days.
Day 9
TEKS 8.7(A)
Explain why the Northern and Southern Hemispheres experience opposite seasons at the same time.
Answer 3
Because of Earth's tilt, when the Northern Hemisphere is tilted toward the sun (experiencing Summer), the Southern Hemisphere is naturally tilted away from the sun (experiencing Winter).
Day 10
TEKS 8.7(B)
The moon is currently in the New Moon phase. Which of the following will occur over the next 14 days?
Select TWO correct answers.
The moon will appear to grow larger (waxing).
The moon will reach the Full Moon phase.
The moon will appear to shrink (waning).
The moon will immediately become a New Moon again.
Answer 1
The cycle from New Moon to Full Moon takes about 14 days (half a month). During this time, the lit portion we see from Earth increases, which is called waxing.
Day 10
TEKS 8.7(C)
Part A
A Spring Tide occurs when the Sun, Earth, and Moon are in a straight line. During which moon phases does this occur?
New and Full Moon
1st and 3rd Quarter
Part B
What is the result of a Spring Tide?
Very high high tides and very low low tides.
Moderate tides with little difference between high and low.
Answer 2
Part A: New and Full Moon
Part B: Very high and very low (Greatest difference)
Spring Tides = Straight line = Stronger pull.
Neap Tides = 90 degree angle = Not as strong (weak).
Day 10
TEKS 8.7(B)
Describe the position of the Moon relative to the Earth and Sun during a Solar Eclipse.
Answer 3
During a Solar Eclipse, the Moon passes directly between the Sun and the Earth. This blocks the sunlight from reaching parts of the Earth's surface, casting a shadow (the Moon is in its New Moon phase).
Gamma rays carry the most energy.
X-rays can be seen by the naked human eye.
Answer 1
The EM Spectrum ranges from low energy (Radio) to high energy (Gamma). Each type of wave gives us different info (e.g., heat from Infrared, composition from Visible).
Day 12
TEKS 8.8(D)
Part A
Why do astronomers use light years instead of kilometers or miles when measuring the distance to stars?
Stars move faster than light.
The distances are too large for standard units.
Part B
If a star is 10 light years away, how long does it take its light to reach Earth?
10 years
10 days
Answer 2
Part A: Distances are too large
Part B: 10 years
A light year is a measurement of distance, not time. It is the distance light travels in one year (about 9.5 trillion km).
Day 12
TEKS 8.8(E)
Describe the "Red Shift" and explain what it tells scientists about the motion of galaxies in the universe.
Answer 3
The Red Shift occurs when light from an object is stretched as the object moves away from us. Because most galaxies show a red shift, it tells scientists that the universe is expanding.
Day 13
TEKS 8.11(A)
Which of the following would be considered abiotic factors that organisms compete for in a ecosystem?
Select THREE correct answers.
Sunlight
Potential Mates
Water
Minerals in the soil
Prey (Food)
Answer 1
Abiotic factors are non-living parts of the environment. Biotic factors are living or once-living parts (like mates and prey).
Day 13
TEKS 8.11(A)
Part A
In a food web, what do the arrows represent?
Who eats who
The flow of energy
Part B
If a disease kills off a large portion of the primary consumers (herbivores), what is the most likely immediate effect on the producers (plants)?
The producer population will increase.
The producer population will decrease.
Answer 2
Part A: Flow of energy (to the eater)
Part B: Producer population will increase
If there are fewer herbivores to eat the plants, the plant population will grow (for a short time) until other factors limit them.
Day 13
TEKS 8.11(A)
Explain the role of decomposers in an ecosystem.
Answer 3
Decomposers (like fungi and bacteria) break down dead organisms and waste. This returns nutrients back to the soil, where they can be used again by producers.
Day 14
TEKS 8.11(B)
A population of moths has both light and dark variations. A volcanic eruption covers the nearby trees in dark ash. According to Natural Selection, what is likely to happen?
Select TWO correct answers.
The dark moths will have a higher survival rate.
The light moths will change their color to dark to survive.
The dark moths will pass on their traits to more offspring.
The light moths will migrate to a new forest.
Answer 1
Natural Selection depends on variation already being present. Organisms with favorable traits (like dark color for camouflage on ash) survive and reproduce more successfully.
Day 14
TEKS 8.11(C)
Part A
A chemical spill pollutes a local lake. What is a short-term impact of this change?
Immediate death of fish.
Evolution of chemical-resistant fish.
Part B
If the chemical remains in the water for many years, what is a long-term impact?
Fish migrate to a different lake.
The species population may decrease or go extinct.
Answer 2
Part A: Immediate death
Part B: Decrease or extinction
Short-term changes happen suddenly and affect individuals immediately. Long-term changes happen over time and affect entire populations and their genetics.
Day 14
TEKS 8.11(D)
Describe one way humans depend on ocean systems and one way human activity has negatively modified them.
Answer 3
Dependence: Oxygen (from algae), food (seafood), climate regulation, transportation.
Modification: Overfishing, plastic pollution, oil spills, runoff from farms (dead zones).
Day 15
TEKS 7.10(C)
A new volcanic island has formed in the ocean. Which of the following describe Primary Succession on this island?
Select TWO correct answers.
It starts with bare rock and no soil.
It starts after a forest fire.
Lichen and Moss will be the pioneer species.
It happens much faster than secondary succession.
Answer 1
Primary Succession occurs in an environment where no soil exists. Lichens break down rock to create soil. Secondary Succession happens when soil is already present (e.g., after a fire).
Day 15
TEKS 7.12(B)
Part A
Which cell organelle is responsible for releasing energy through cellular respiration?
Chloroplast
Mitochondria
Part B
Which of the following is found ONLY in plant cells?
Nucleus
Cell Wall
Answer 2
Part A: Mitochondria (The powerhouse!)
Part B: Cell Wall (and Chloroplasts)
Both plants and animals have a nucleus and mitochondria. Only plants have chloroplasts (for photosynthesis) and a cell wall (for structure).
Day 15
TEKS 7.12(D)
Describe the main function of the human circulatory system and how it interacts with the respiratory system.
Answer 3
The Circulatory System transports oxygen and nutrients to cells and removes waste (\( CO_2 \)). It interacts with the Respiratory System in the lungs, where the blood picks up oxygen and drops off carbon dioxide.
YOU ARE READY!
| Day | Q1 | Q2 | Q3 |
|---|
| 11 | Nuclear Fusion; H & He 8.8A | A: Main Seq; B: Bright/Temp 8.8B | Universe Hierarchy 8.8A |
| 12 | Small part; Gamma Energy 8.8C | A: Distance; B: 10 years 8.8D | Red Shift/Expansion 8.8E |
| 13 | Sun, Water, Minerals 8.11A | A: Energy Flow; B: Producers Up 8.11A | Role of Decomposers 8.11A |
| 14 | Dark survives; Pass traits 8.11B | A: Immediate Death; B: Extinction 8.11C | Human Ocean Mod. 8.11D |
| 15 | No soil; Lichen/Moss 7.10C | A: Mitochondria; B: Cell Wall 7.12B | Circulatory/Resp interact 7.12D |
*TEKS references based on 2024-2025 standards for Grade 8 Science.
