1.4 - Size, Scale and Estimations and 1.5 - Units and Standard Form Flashcards
How do you calculate the magnification of a light microscope?
Magnification of the eyepiece lens x magnification of the objective lens
How do you determine the size of an object in microscopy?
Size of image / magnification = size of object
This formula can be rearranged to obtain the other values, make sure you are in the same units!
What is standard form in the context of microscopy calculations?
Standard form is used for very large or small numbers by multiplying a certain number by a power of 10.
What is the range for the ‘number’ in standard form?
The ‘number’ being multiplied by a power of 10 needs to be between 1 and 10.
Standard form example: 5 × 10⁻⁵
Answer: 0.000015
Standard form example: 3.4 × 10³
Answer: 3400
What do we use orders of magnitude for?
We use orders of magnitude to describe how much bigger or smaller one object is compared to another.
How do orders of magnitude help in biology?
They help us compare sizes in biology, like cells and organelles.
If an object is 10 times bigger than another, how is it expressed in orders of magnitude?
It is expressed as 10¹ times bigger.
If an object is 1,000 times bigger, how is it expressed in orders of magnitude?
It is expressed as 10³ times bigger.
If an object is 10 times smaller than another, how is it expressed in orders of magnitude?
It is expressed as 10⁻¹ times smaller.
What is the prefix for 0.01?
Centi
Symbol: m
What is the prefix for 0.001?
Milli
Symbol: m
What is the prefix for 0.000001?
Micro
Symbol: m
What is the prefix for 0.000000001?
Nano
Symbol: n
What is the purpose of estimations in biology?
Estimations help when it’s impractical to count every item in a population or area.
How do you estimate the total number of dandelions in a field?
You sample a 1m x 1m square of grassland and count the dandelions in that square, then multiply by the total number of squares in the field.
What is the estimated total number of dandelions if you count 15 in a 1m x 1m square of a 50m x 50m field?
The estimated total dandelions is 37,500.
Calculation: 15 × 2,500 = 37,500
Why are estimations useful for scientists?
Estimations help scientists quickly assess population size without needing to count every individual.
