Independent variable (what you have control over)? Dependent variable (what you
ID: 210808 • Letter: I
Question
Independent variable (what you have control over)? Dependent variable (what you measure to detect any effect) = ? What are some variables you would want to "control," or keep constant among yo Some practice Question: Does salt consumption increase blood pressure? Independent variable: Dependent variable: Other variables to control Question: Does sunlight exposure increase the risk of developing skin cancer? Independent variable: Dependent variable: Other variables to control: Measurements Figure from online.science.psu.eduExplanation / Answer
1) Yes, consuming of more salt could lead to increased blood pressure. There are a series of reactions driven because of this event. Initially the kidney gets affected, the function of the kidney is draw excess fluids from the blood and push out unwanted waste fluids through urine. This is done by the kidney with the help of sodium ions in the blood, when excess of sodium ions are present the balance is lost and kidney wont be able to draw water of other fluids from the blood.
This gives impact on the arteries leading to the heart. Increased amount of salt in the blood makes the blood thicker which puts pressure on the thin arteries, so hold that pressure the walls of the arteries thickens up which leads to narrowing the passage. This gives lesser flow of blood to heart and brain giving us blood pressure.
2) UV radiation from the sun in adequate amount is good for the skin, but direct and more exposure to the sun giving out UV radiations are harmful to the skin.
These UV radiations fall on the skin penetrate deep and causes cell damage, UV rays could cause DNA damage or in other words mutations in the DNA which could lead to skin cancer called as Melanoma. Use of sunscreen lotions can not stop the UV rays from damaging the DNA. We need to protect ourselves by not exposing ourself to sun for longer time. Covering our body mainly, hand and legs while going out in sun could be helpful.
3) Units and Abbreviations for Length, Mass and Volume:
Length - Meters (m)
Mass - Grams (g)
Volume - Liters (l).
4) Conversion practice:
1 kilometer = 1000 meters
1 meter = 100 centimeters
1 centimeter = 100 millimeter
similarly, 1 kilogram = 1000 grams
1 gram = 1000 milligrams
1 liter = 1000 milliliters
Now examples:
8 km = 8000 m
17 m = 17000 mm
61 mm = 6.1 cm
3.9 cm = 39 mm
1 l = 1000000 µl
10,000 mg = 10 g
343 g = 343000 mg
0.05 kg = 50 g
46 mm = 0.046m
5) Logarithms:
log10 100 = 2
log10 10,000 = 4
log10 1000000 = 6
log10 0.00001 = -5.
6) Match the following:
Stage - Provides flat surface for specimens.
Stage adjustment knob - Moves the stage up and down rapidly.
Light intensity knob - changes lamp brightness.
Interpupilary adjustment - allows both the eyes to see the image simultaneously.
Coarse focus knob - allows light to pass through the specimen.
Fine focus knob - moves the stage up and down in tiny amounts.
Iris diaphragm - Aligns the light waves before they pass through the specimen.
Condenser - closes down the amount of light and sharpens the image.
Condenser adjustment lever - lifts or lowers the condenser.
Specimen holder - moves a slide side to side or front and back.
Eye piece length adjustment - should be set so that both the eyepiece are at same length.
Electrical cord - should only be detached by holding the plug.
7) Rearranging the sentences in order:
1) clean all lenses with lens paper.
2) Place the specimen on stage.
3) Adjust the chair to comfortable height.
4) Rotate lowest magnification objective lens into position (probably 4x or 10x).
5) Move the objective lens to increase magnification.
6) Use coarse fine adjustment knob to adjust until an image is visible.
7) Be careful on use only the fine adjustment knob with the longest objective lens.
8) Remove the specimen, lower the stage, wrap cord, and return covered microscope to the numbered shelf.