Cells Flashcards
Cells
Basic blocks of life
Cell membrane
Controls what goes in and out of the cell
Ribosome
Protein synthesis
Nucleus
Contains DNA arranged in chromosomes
mitochondria
Site of aerobic respiration
cytoplasm
jelly like fluid site of chemical reactions
Cell wall
Made of glucose gives plant extra strength
Vacuole
Filled with cell sap keeps the plant rigid
Chloroplasts
Site of photosynthesis
organ
organ system
dna
cell
tissue
place these in size order
dna cell tissue organ organ system
1mm in micrometres
1000 micrometres
1 micrometer in nano metres
1000 nanometres
order of magnitude
difference caculated in factors of 10, represented by standard form
uni cellular / multi cellular
an organism made of one cell/an organism made of multiple cells
tissues
a group of similar cells working together to perform a similar function
organ
a group of tissues working together to perform a similar function
organ system
a group of organs working together
magnification
how much bigger the image size is compared to the actual size (m=i/a)
resolution
the ability to distinguish between two points clearly
prokaryote / prokaryotic cell
a cell without a nucleus , its dna is not organised into chromosomes (its dna exists in one long string)
eukaryote / eukaryotic cell
dna organised in chromosomes in a nucleus
nucleoid
naked dna , dna that is not org in a chromosome
specialised cell
a cell designed to carry out a specific function
differentiation
the process in which an unspecalised cell becomes specalised
stem cells
unspecialised cells that have the ability to differentiate
3 similarities between plant cells and animal cells
they both have a
- cytoplasm
- nucleus
- cell membrane
- ribosome
- mitochondria
3 similarities between prokaryotes and eukaryotes
-cell wall
-cell membrane
-cytoplasm
3 differences prokaryotes and eukaryotes
-eukaryotes are larger than prokaryotes (prokaryotes 0.2-2micrometres)
- only prokaryotes can have a nucleoid , plasmid, pili or capsule
- eukaryotes have a nucleus
prokaryote cell wall
cellulose / chitin
eukaryote cell wall
peptidoglycan
flagellum
tail adapted for movement of cell
pili
attaching to surfaces
plasmids
small circular rings of dna
capsule
prevents the cell from drying out
sperm cells function and adaptations
function - fertilise an egg
adaptations - tail for movement, acrosome for breaking into egg
nerve cells functions and adaptations
function - carries messages / electrical impulses for movement
adaptation - a gap in myelin sheath which allows nerve impulses to jump from gap to gap
red blood cell functions and adaptations
function - transports oxygen from lungs to tissues
adaptations - tiny so easier to pass through capillaries, bioncave disc no nucleus
hair root cell functions and adaptations
function - found on plant roots to absorb water and mineral ions
adaptation - long thin exchange surface no cuticle
palisade cells
function - absorb max amount of light possible
adaptation - near surface arranged end on
phloem cells functions and adaptations
function :form columns / tubes from dead cells , movement of sugars
adaptations - small pores
xylem cells function and adaptions
function - transports water from roots to rest of the plant
adaptation - lignin protein on inside keeps open under pressure
onion cell practical instructions
1) using tweezers cut a piece of onion. break piece in half and tweeze off transparent layer
2)spread piece on a microscope slide
3)2 drops iodine
4) place coverslip ontop with tweezers use paper towel wipe off excess
5)objective lense to 40x
Why should i lower the slide at an angle
prevents air bubbles
risk assesment onion practical
handling sharp knife, staining with blue iodine
rules of scientific drawing
1) use a pencil
2) no shading
3) smooth lines
4) labelling perpendicular
embryonic stem cells
can become any type of specalised cell
totipotent
can become any type of specalised cell
adult stem cells / bone marrow
limited can only become a certain number of specalised cells
multipotent
limited can only become a number of specalised cells
meristem
tip of root/shoot, undifferentiated cells are formed here
how to write a comparative statment
-mention both species
-however, whereas, on the other hand
-differences+similarities
-words ending in er (smaller bigger etc)
therapeutic cloning
using stem cells for creation of body cells to treat disease
benefits of destroying an embryo for stem cell research
totipotent, free people from incurable disease, stem cell from umbilica chord otherwise be discarded
issues with destroying a embryo for stem cell research
- creation artifical life is controversial
- considered a loss of life
- embryo cannot consent
- unreliable technique
where are eukaryotic cells found
animal plant fungi protists usually multi cellular organisms
where are prokaryotes found
bacteria and archaea uni cellular organisms
in the onion cell rqp name a hazard risk and mitigation attempt
iodine stain is an irritant so wash hands if in contact
knife can cut your skin so cut away from blade
why is the coverslip lowered at an angle in the onion cell rqp
to prevent air bubbles
why is the stain used in the onion cell rqp
to identify organelles clearly
why is a thin layer of onion used in the onion cell rqp
cells are easier to see because light is let through
What are the stages of the cell cycle
growth
dna replication + mitosis
division
what happens in the first stage of the cell cycle
cell grows and increases number of sub cellular structures (ribosomes mitochondria)
what happens in stage 2 of the cell cycle
dna condenses into chromosones and chromosones are duplicated
what happens in stage 3 of the cell cycle
spindle fibres attach to the chromosones . they are lined up at the equator of the cell and pulled apart by fibres towards poles (daughter chromosone goes one way og chromosome another). the cell splits at each pole, now two cells containing identical dna
gene
a section of dna
chromosone
a singular strand of dna
4 stages of mitosis
prophase, metaphase, anaphase, telophase
what happens during prophase
-chromosones thicken and coil
-nucleus disapears
what happens during metaphase
chromosones attach to spindle fibres and line up at the equator
what happens during anaphase
spindle fibres pull identical chromosones to opposite ends of the cell
what happens during telophase
nucleus is reformed
cell splits into an identical cell containing same dna as original cell
