What is the function of the cell membrane?
to control which substances move in and out of the cell
A human eats vegetables, what describes the position of the human in the food chain AND which trophic level would the human be in?
primary consumer, first trophic level
what is teh vertical column of elements in the Periodic Table Called?
a group
State the names of the eight planets in order, starting from the Sun.
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.
What electrical component is used to specifically vary the current in a circuit?
A variable resistor.
An animal cell is placed in a solution with a lower water potential than its cytoplasm. Describe the net movement of water.
Net movement of water out of the cell.
What enzyme is responsible for chemcial digestion of starch
amylase
What type of chemical bond is formed between two non-metals?
covalent
What is the definition of "acceleration"?
The rate of change of velocity.
What is a "control variable" in a scientific investigation?
A variable that is kept constant to ensure the results are due only to the independent variable.
Explain why a "clean water supply" is a critical public health measure for controlling the spread of certain pathogens.
It prevents the transmission of water-borne diseases (like cholera) that are spread through contaminated feces
Describe one common method used to conserve endangered species.
Habitat protection, captive breeding programs, or legal protection
What happens at the anode during the electrolysis of molten aluminum oxide?
aluminum ions lose electrons to form aluminum gas
What happens to the pressure of a gas if its volume is decreased at a constant temperature?
The pressure increases.
In an electrolysis experiment, why is it necessary for the electrolyte to be "molten" or in "aqueous solution" for electricity to flow?
So the ions are free to move and carry the charge to the electrodes.
Define "homeostasis."
The maintenance of a constant internal environment.
What is the function of the stomach in the digestive system and what enzyme is most used
Digestion of proteins using protease
Balance the equation:
___ NH3 + ___ O2 --> ___ N2 + ___ H2O
4NH3 + 3O2 --> 2N2 + 6H2O
If a car slows down from 20 m/s to 5 m/s in 5 seconds, what is its deceleration?
3 m/s2
In a circuit diagram, what does a straight line represent?
A connecting wire.
In the carbon cycle, what is the name of the process by which decomposers release carbon dioxide back into the atmosphere?
Respiration
Why does starch need to be digested before it can be aborbed by the body?
Starch molecules are too large and insoluble to pass through the intestine wall
Explain why covalent compounds usually have low melting and boiling points.
They have weak intermolecular forces that require little energy to overcome.
A satellite orbits at a radius of 7200 km and takes 2 hours to complete one orbit. Calculate its orbital speed in m/s with 2 significant figures.
6300 m/s
Why is methane often burned rather than allowed to escape into the atmosphere?
It is a potent greenhouse gas that contributes to global warming.