B1 Flashcards
define what a eukaryotic cell is
Eukaryotic cells contain a nucleus and other membrane-bound organelles
define what a prokaryotic cell is
A cell that does not have a nucleus – the DNA is free in the cytoplasm
features of prokaryotic cells
Small, no nucleus
how many micro metres are in a mm
1000
how many mm metres are in a micro metre
0.001
Which organelles are shared by animal and plant cells?
cytoplasm, cell membrane, nucleus, mitochondria
which organelles are found only in animal cells?
centrioles, lysosomes
which organelles are found only in plant cells?
Vacuole, chloroplasts, cell wall
Order these steps in the required light practical:
-place the slide
-use the coarse focus
-use the fine focus
-record findings in image
-start at the lowest power
1) start at the lowest power
2)place the slide
3)use the coarse focus
4)use the fine focus
5)record findings in image
What is the function of mitochondria?
produces energy “powerhouse of the cell”
What is the function of the nucleus ?
Controls the cell, contains genetic information
What is the function of ribosomes?
protein synthesis
What is the function of the vacuole?
structural support, stores waste and nutrients
What is the function of the cell wall?
provide structure to the cell
What is the function of the cell membrane?
Controls what enters and exits the cell
What is the function of cytoplasm?
Where chemical reactions take place, holds organelles in place
define magnification
making an object appear larger than its actual size when viewed through a microscope
define resolution
the ability to distinguish between two points in a microscope image
What makes electron and light microscopes different?
Electron microscopes have more magnification and resolution compared to light microscopes but cost more
What is the formula for magnification?
magnification= size of image/size of real object
Describe how genetic information is stored in the nucleus of a cell
stored in dna which is in the shape of a double helix. has 46 chromosomes
Order the stages of mitosis (read all lewis):
-cell begins to divide
-membrane breaks down, chromosomes line up in the middle
-DNA replicates and forms two copies of each chromosome
-cytoplasm and cell membrane divide
-one set of chromosomes is pulled to each end
1)cell begins to divide
2)DNA replicates and forms two copies of each chromosome
3)membrane breaks down, chromosomes line up in the middle
4)one set of chromosomes is pulled to each end
5)cytoplasm and cell membrane divide
What do you call a cell that has just been copied?
daughter cells
define stem cells in animal cells
unspecialized cells that can divide and differentiate into many types of cells, including specialized cells
define stem cells in plant cells
undifferentiated cells located in the meristems of plants
how are stem cells used?
clone plants and therapeutic cloning
Define diffusion
the process in which particles move from an area of high concentration to an area of low concentration
What are the factors that effect the rate of diffusion?
temperature, surface area, concentration gradient, distance
describe the process of osmosis
water molecules move through a semipermeable membrane from an area of high water concentration to an area of low water concentration
define active transport
the process of moving molecules into or out of a cell against a concentration gradient, using energy to overcome resistance
common example of active transport
root hair cells move minerals from the soil into the plant, where the concentration of the minerals is higher
