Key terms (bridging work) Flashcards
When is a result accurate?
When it is close to the true value
What are precise results?
When repeat measurements are consistent
Define measurement error
The difference between a measured value and the true value
What is the uncertainty of a measurement?
The interval within which the true value is expected to lie
what type of error is caused by results varying around the true value in an unpredictable way?
Random error
What is systematic error?
A consistent difference between measured values and true values
What does zero error mean?
A measuring instrument gives a false reading when the true value should be zero
What formula can be used to calculate magnification?
Magnification= size of image/actual size
What is an eyepiece graticule?
A glass disc that fits on top of the eyepiece lens that is marked with a fine scale from 1-100
What is a stage micrometer?
a microscope slide with a very accurate scale in micrometers engraved on it
What is resolution?
the ability to see individual objects as separate entities
What is the nucleolus?
area within the nucleus that is responsible for producing ribosomes
What are vesicles?
membranous sacs that are used to transport materials in the cell
What are lysosomes?
specialised forms of vesicles with hydrolytic enzymes that break down waste material in cells
What is the role of the cytoskeleton?
controls cell movement, movement of organelles within the cell, and provides mechanical strength to the cell
Name 3 types of cytoskeletal filaments
microfilaments, microtubules, intermediate fibres
Give 2 types of extension that protrude from some cells
Flagella (whip like protrusions) and cilia (tail like protrusions)
What is endoplasmic reticulum? (ER)
a network of membranes enclosing flattened sacs called cisternae
What are the functions of the 2 types of ER?
smooth ER = lipid and carbohydrate synthesis, and storage
rough ER = synthesis and storage of proteins
What is the function of the Golgi apparatus?
plays a part in modifying proteins and packaging them into vesicles
