Scientific Method and Lab Equipment
What glass container has a narrow neck and a cone-shaped base, making it ideal for swirling liquids without spilling?
Erlenmeyer flask.
What visual model shows a single, linear path of energy transfer from a producer to consumers?
A food chain.
What type of forces are Friction, normal force, magnetism and gravity?
Friction and normal force are examples of contact forces, while magnetism and gravity are Non-contact forces (or action-at-a-distance forces).
Explanation: Non-contact forces push or pull objects without direct physical touch.
Which scientist proposed the theory of evolution by natural selection after observing finches and tortoises in the Galápagos Islands?
Charles Darwin.
Which organelle is known as the "powerhouse of the cell" because it carries out cellular respiration to produce ATP energy?
Mitochondrion (plural: mitochondria).
When you need to measure the volume of a liquid with high accuracy in the laboratory, which tall, narrow piece of equipment should you use?
A graduated cylinder.
Place these biological levels of organization in order from smallest to largest: Community, Organism, Ecosystem, Population.
Organism, Population, Community, Ecosystem.
As a roller coaster car rests at the very top of a tall hill, it possesses maximum (Answer A) energy. Once it starts moving downhill, this energy transforms into (Answer B) energy. Identify both (A) and (B).
(A) Gravitational Potential Energy (GPE) and (B) Kinetic Energy (KE).
Explanation: At the highest point, height is maximized, giving the car maximum GPE. As it moves downhill, height decreases and speed increases, converting GPE into KE.
Which early scientist incorrectly suggested that organisms could pass on traits acquired during their lifetime (for example, a giraffe stretching its neck and passing a longer neck to its offspring)?
Jean-Baptiste Lamarck.
Unlike eukaryotic cells, prokaryotic cells (like bacteria) lack which major membrane-bound organelle that stores genetic material?
The nucleus.
1. A student tests three paper airplanes. She keeps the paper size, room temperature, and throwing force the same, but changes the wing shape. What are these unchanged factors called?
2. In an experiment testing how different amounts of fertilizer affect plant growth, This is the factor that the scientist intentionally changes or manipulates.
1. Controlled variables (or constants).
2. The Independent Variable
Barnacles attach themselves to the skin of whales. The barnacles gain transportation and food, while the whale is neither helped nor harmed. What type of symbiotic relationship is this?
Commensalism.
Which lunar phase occurs when the Moon is positioned between the Earth and the Sun, making it completely dark and invisible from Earth?
New Moon.
In a population of beetles, dark beetles survive better on dark tree bark than green beetles, leaving more offspring. Over time, the population becomes mostly dark. What is this process called?
Natural selection.
Name TWO organelles or structures found in plant cells that are NOT present in animal cells.
Cell wall and Chloroplasts (or Large central vacuole).
A student hypothesizes that "caffeine increases heart rate." In their experiment, the average heart rate without caffeine was 72 bpm and with caffeine was 71 bpm. The student concludes: "My hypothesis was wrong, so my experiment was a failure and invalid." Identify TWO reasons why this student's scientific reasoning is incorrect.
A rejected (or unsupported) hypothesis does NOT mean the experiment failed; refuting a hypothesis is a valid scientific result.
A single trial with a 1 bpm difference is not statistically significant to prove or disprove a effect without multiple trials and variable control.
Two male lions fighting over the same hunting territory is an example of what specific type of ecological competition?
Intraspecific competition.
What giant clouds of gas and dust in deep space are often called "stellar nurseries" because new stars are born inside them?
Nebulae (or Nebula).
What theory about the origin of life were scientists Stanley Miller and Harold Urey trying to support with their famous 18-step experiment, and HOW did they model early Earth conditions in their lab setup?
Theory: The Primordial Soup theory / Chemical Evolution (that organic molecules necessary for life could form spontaneously from non-living inorganic matter).
How they modeled it: They sealed methane, ammonia, hydrogen, and water vapor in sterile glass flasks and passed electric sparks through it to simulate early Earth's atmosphere and lightning.
Which organelle contains digestive enzymes that break down waste materials, cellular debris, and foreign invaders inside the cell?
Lysosomes act as the recycling and waste disposal system of the cell.
Look at this data: Group A (0g salt): 15 cm growth | Group B (5g salt): 8 cm growth | Group C (10g salt): 1 cm growth. Identify the dependent variable AND state the trend shown in the data.
Dependent variable: Plant growth. Trend: Increasing salt concentration decreases plant growth.
If a grassland ecosystem has 10,000 kg of producer biomass, according to the 10% rule of energy transfer, how much biomass can be supported at the secondary consumer level?
100 kg.
Explanation: Producers (10,000 Kg), Primary Consumers (1,000 kg), Secondary Consumers (100 kg). Only 10% of energy/biomass passes to the next trophic level.
What cosmic entity forms when a massive star collapses under its own gravity, creating a region where gravity is so strong that not even light can escape?
A black hole.
Why is genetic variation within a population essential for natural selection to occur when an environmental change happens?
Without variation, no individuals might possess the traits needed to survive the change, leading to extinction.
A cell is synthesizing a high volume of proteins to be exported outside of its membrane. Trace the correct path of these proteins through THREE organelles involved in synthesis, packaging, and transport.
Answer: Ribosome,Endoplasmic Reticulum (Rough ER), Golgi Apparatus.
Explanation: Ribosomes build proteins, the Rough ER folds/modifies them, and the Golgi packages them into vesicles for export.