B1 Cells Flashcards
Eukaryotic cells
Cells that possess a membrane bound nucleus that holds genetic material
Prokaryotic cells
Cells that lack cell nucleus
Average size of a Eukaryote
5um-100um
Ave size of a prokaryotic celll
0.2um-2.0um
How do eukaryotes divide
Mitosis
Function of cell membrane
Permeable to some substances but not others to control what goes in and out of the cell
Function of cytoplasm
Jelly like substance that contains dissolved nutrients, salts and structures called organelles. This is where many chemical reactions happen
Mitochondria
Contains enzymes for respiration to take place
Nucleus
Where genetic material is stored- controls cells activities
Ribosome
Where protein synthesis occurs
Cell wall
Strengthens and supports cell ( it can help a plant keep its shape)
Permanent Vacuole
Contains cell sap to keep cell turgid
Chloroplasts
Contain chlorophyll which absorbs light energy for photosynthesis
Plasmid
Rings of DNA
How do prokaryotes divide
Binary fission
Vacuoles in animal cells
Temporary used to store and transport substances
What are the contents of a plant cell
Cytoplasm, nucleus, cell membrane, mitochondria, ribosomes, chloroplasts, cell wall, permanent vacuole.
What do prokaryotic cells contain
Cytoplasm, ribosomes, no mitochondria or chloroplasts, DNA is a single molecule additonal DNA is found on plasmids
What is the cell wall made off
Cellulose
Sperm cell specialisations
Tail-swimming, midpiece containing mitochondria, haploid nucleus,acrosome containing enzymes so sperm can penetrate egg
Define specialised
Adaptations which help them to carry out a particular function
Define differentiation
When cells become specialised
What specialisations does a nerve cell have
Dendrites to make connections with other neurons, long axon to carry impluses to target organ, myelin sheath insulates axon - increaes speed at which messages can travel, very long and thin
What specialisations does a muscle cell have
Expand and contract
How do plants absorb water from the soil
Osmosis
How do plants absorb mineral ions from the soil
Active transport
How is a root hair cell adapted for its function
Large SA
Lots of mitochondria
What is translocation
Transports sugars through the plant
What is lignin
Strenghtens the xylem tubes
Transpiration stream
This is what is formed when water flows through the xylem continuously
Which way does cell sap go through the phloem tube
Both directions
What stage do animal cells differentiate
Early stage
When do plant cells differentiate
Plant cells maintain the ability to differentiate through out their whole life
Haploid
Nuclei only contain half the number of chromosomes that you find in a normal body cell
Diploid
46 chromosomes
Zygote
Diploid cell resulting from the fusion of two haploid gametes
Where does medicine already use adult stem cells
Stem cells from bone marrow of a healthy person can replace faulty blood cells
What is a risk of using stem cells in medicine
Stem cells grown in a lab could be contaminated by a virus
Why are plant stem cells so useful
They can quick and easily create clones
