Experimental Design
A baker wants to see if changing the amount of yeast in a recipe makes bread loaves rise higher. What is the independent variable?
the amount of yeast used
You look through a microscope at a slice of cork tissue. What thick, boxy outer structure lets you know immediately that you are looking at plant cells rather than skin cells?
the cell wall
Small feeder fish hide safely inside the poisonous tentacles of a sea anemone. The sea anemone is completely unbothered and unaffected by their presence.
What type of symbiotic relationship is this, and what does it mean for both organisms?
Commensalism (+,0)
One is benefited while the other is neither helped nor harmed
According to evolution, how did certain physical traits—such as marine mammals developing specialized blowholes—take place?
Why do heavy industrial work boots that construction workers use have deep, rough grooves cut into their hard rubber soles instead of being perfectly flat and smooth?
To increase friction between the boot and the ground to prevent slipping.
A baker wants to see if changing the amount of yeast in a recipe makes bread loaves rise higher. What is the dependent variable?
the height of the bread loaves.
What important organelle acts like an active security guard, wrapping around animal cells to decide exactly what molecules can drift inside or get kicked out?
cell membrane
An intestinal worm hitches a ride inside a wild salmon, absorbing the fish's nutrients and leaving the salmon weak and sickly.
What type of symbiotic relationship is this? And what does this mean for both organisms?
Parasitism (+,-) One benefits and one is harmed
If a flock of geese flies to an island with zero predators and an endless field of grass, its population will spike. Why won't the population keep growing forever?
It will reach its carrying capacity when limiting factors like space, nesting sites, or total food supply flatten out the curve.
A flying drone bumps directly into a brick chimney with a forward force of 15 Newtons. According to Newton's 3rd Law, what force does the chimney apply back to the drone?
Exactly 15 Newtons of force in the opposite direction.
If you are testing how different brands of laundry detergent remove grass stains, why must you use the exact same water temperature and fabric type for every single wash load?
To control variables/constants so you ensure it is a fair test (proving only the detergent caused the results).
If one side of a unzipped DNA molecule reads C-C-T, what will the matching complementary base-pair strand read?
G-G-A
C pairs with G
A pairs with T
Two different species of sharks are aggressively hunting in the exact same shallow reef for a dwindling school of tuna.
What ecological interaction is happening between the sharks?
Competition
If a sudden, extreme ice age strikes an environment, what are 3 reasons an entire animal species might completely fail to adapt and go extinct?
they cannot find alternative food sources
they cannot camouflage against the new landscape
they are too slow/unsuited (not able) to migrate away
A broken-down golf cart is sitting on a path. Two golfers push it forward from behind with a total force of 180 Newtons, while a heavy gust of wind blows directly against the front of the cart with a force of 30 Newtons. What is the net force?
150 Newtons
(180 N - 30 N = 150 N)
A scientist tracks a balloon filled with gas. As they cool the gas down from 40 degrees Celsius to 0 degrees Celsius, the volume of the balloon drops from 10 Liters to 7 Liters.
What is the trend between temperature and volume?
*See slides for graph*
As temperature decreases, the volume decreases (direct relationship)
Two Golden Retriever puppies born in the same exact litter look noticeably different—one has a darker coat and one has a lighter coat. Explain why this happens using chromosomes.
They inherited completely different random combinations of chromosomes from their mother and father (23 from mother and 23 from father - 46 total)
A leopard seal spots an emperor penguin on the ice, stalks it, kills it, and eats it. What is the ecological relationship between these two animals?
Predation (Predator/Prey)
: If human industries clear thousands of acres of green jungle (forests) to clear space for cattle (farms), what immediate negative change happens to the gases in the global atmosphere?
Carbon dioxide (CO2) levels rise immediately because they are fewer plants absorbing it
An electric skateboard travels down a path at a steady speed of 6 m/s. If the rider travels for a total of 30 seconds, how far did they go? Remember units!
Speed = Distance/Time
Distance = Speed x Time
180 meters (6 x 30 = 180)
An experiment looking at baking powder shows that a cake's fluffiness increases with every gram of baking powder added up to 10 grams, but adding 15 grams of baking powder causes the cake to collapse entirely.
What conclusion can you make about this ingredient?
*See graph on slides*
Baking powder helps grow the cake up to a specific optimal point, but exceeding that limit (10 grams) hurts the results.
If an error happens while a cell is copying its genetic code, resulting in a sudden change in the base sequence, what is this called and is it always bad?
A mutation; it is a natural process that can be helpful, harmful, or completely neutral.
Plankton uses sunlight to create sugar, small shrimp eat the plankton, and a sea duck eats both the plankton and the shrimp.
How would you classify the sea duck?
Omnivore (eats both producers and consumers)
An organic vineyard wants to eliminate leaf-eating beetles without ruining the local water supply. Why is introducing a native species of beetle-eating ladybugs better than using chemical sprays?
It is a natural control method that does not produce toxic runoff and prevents damage to the surrounding ecosystem.
A toy rocket with a mass of 3.0 kg is launched into the air. If the rocket motor exerts a net force of 27 Newtons, what is the acceleration of the rocket? Remember units!
Force = mass x acceleration
Acceleration = Force/mass
9 m/s2
(27/3 =9)