Biology
What organelle controls the activities of the cell?
The nucleus
Name this compound: Fe2O3
Iron III oxide
What is the scientific name for near- sightedness, and what can people with this condition see clearly?
Myopia, People can see close objects clearly, but struggle with far objects.
What is the difference between a physical change and a chemical change?
Physical change does not form a new substance; chemical change does
you leave a metal spoon in vinegar overnight and see it changes colour. Is this a physical or chemical change? what evidence supports your answer?
- chemical change: new substance formed (colour change indicates reaction occurred)
What is the purpose of mitosis?
Body cells undergo mitosis to produce identical cells for growth, repair, and replacement of damaged or worn- out cells. Aka- cellular proliferation
Determine if the compound is ionic or covalent, then name it: P2O5
Covalent
Diphosphorus pentoxide
What type of mirror is used in a store security mirror (Corner mirror), and why?
Convex, because it gives a larger field of view, allowing workers to see more of the store.
Why do cells need a selectively permeable membrane?
To control what enters and leaves the cell to maintain homeostasis
Two substances are mixed and the temperature drops. What does this suggest about the reaction?
Likely endothermic (absorbs energy)
What is a carcinogen, and how can it contribute to cancer? Give one example.
A carcinogen is a cancer- causing substance or factor. It can damage DNA and cause cells to divide uncontrollably. Examples include: tobacco smoke, and UV radiation.
Balance this equation and identify the reaction type: Al+ O2-> Al2O3
4Al+ 3O2-> 2Al2O3
Synthesis
The index of refraction of vegetable oil is 1.47 if light travels at 3.00X10^8 m/s in air, what is the speed of light in vegetable oil?
n=C/V
V= 3.00 X 10^8/1.47
=2.04 X 10^8 m/s
In a chemical reaction, why is mass always conserved in a closed system?
Atoms are rearranged, but not created nor destroyed.
A light ray passes through a glass block and exits parallel but shifted sideways. Why?
It refracts when entering and leaving the glass, changing speed each time. The 2 bends cancel in direction, but the sideways shift happens because the light ray travels through the block at an angle
What are the four components of blood and their function?
-Plasma: Plasma helps maintain blood pressure and regulates body temperature.
-Red blood cells OR (erythrocytes): They transport oxygen from the lungs to all of the living tissues of the body and carry away carbon dioxide
- White blood cells, OR leukocytes : Some white cells are involved in defending the body against both infectious disease and foreign materials
- Platelets: Platelets ,are cell fragments without nuclei that work with blood clotting chemicals at the site of wounds. They do this by adhering to the walls of blood vessels, thereby plugging the rupture in the vascular wall.
A solution has a pH of 13.9: is it acidic, basic, or neutral? Would phenolphthalein stay clear or turn pink?
Basic, Turns pink
A convex mirror forms an image. Describe the image using SALT characteristics.
Size-> smaller
Attitude-> upright
Location: Behind mirror
Type-> virtual
Why does a fish appear closer to the surface than it actually is when viewed from above water?
- Light refracts as it moves from water to air, changing direction
A student mixes 2 clear solutions and a solid forms. What does this tell you about what happened at the particle level?
the particles rearranged and formed a new substance that is insoluble, so it appears as a solid (a precipitate)
In key points explain how the digestive, respiratory, and circulatory systems work together to provide energy for body cells.
The digestive system breaks food into nutrients such as glucose, the respiratory system supplies oxygen, and the circulatory system transports glucose and oxygen to cells where cellular respiration releases energy.
Calcium reacts with water: Ca+H2O->H2+ Ca(OH)2 A) Balance the eqtn B) identify reaction type C) Explain what you would observe in the test tube D) predict final pH
Balanced: Ca+2H2O->H2+ Ca(OH)2
b) single
c) Bubbles form (hydrogen gas), calcium dissolves, test tube may warm up
D) Basic pH (>7) because Ca(OH)2 is a base
A ray of light travels from air into glass. What happens to the speed of light? Does the ray bend toward or away from the normal? Explain why this happens? If the angle of incidence keeps increasing while light tries to leave glass and enter air. what optical phenomenon can eventually occur?
- speed decreases because glass is more optically dense. - ray bends towards the normal. - Happens bc light slows sown in denser materials, changing direction (refraction) -Total internal reflection can occur if the angle becomes large enough
A student places a plant cell in salt water and observes it shrinks. At the same time, a straw looks bent in water. What process explains each observation, and what is ONE similarity between them?
- shrinks due to osmosis (water moves out of the cell from high to low concentration through a membrane)
A plant's leaves are damaged so that the palisade layer is thinner than normal and stomata are partially blocked predict 2 effects on the plant and why?
- Reduced photosynthesis because fewer cells are available to absorb light. Reduced gas exchange due to blocked stomata limiting CO2 entry.