B1 Flashcards
what are the two types of cells?
-eukaryotic (plant/animal)
-prokaryotic (bacteria)
what are the differences between prokaryotic and eukaryotic cells?
-prokaryotic cells are much smaller than eukaryotic
-eukaryotic cells contain a nucleus whilst prokaryotic do not
what are plasmids?
small loops of DNA found in the cytoplasm
Definition of a eukaryotic cell?
contain genetic material(DNA) in an enclosed nucleus
Definition of a prokaryotic cell?
genetic material(DNA) is not stored in the nucleus
how are sperm cells adapted to carry out their function?
-contain half genetic information
-long streamlined tail
-contain a lot of mitochondria
how are root hair cells adapted to carry out their function?
-large surface area to increase rate of absorbsion
-do not contain chloroplast
-many mitochondria for energy
how are xylem adapted to carry out their function?
-end walls are broken down forming a hollow tube,so no obstruction to water flow
- no nucleus cytoplasm ,vacuole, chloroplast
-has lignin
how are phloem adapted to carry out their function?
-Made of living cells
-seive plates and companion cells
-seive plates contain pores so dissolved sugars can flow through
-companion cells contain alot of mitochondria for energy
what is a stem cell?
-undifferentiated cell
what does a stem cell do?
-give rise to more cells of the same type
-can differentiate to form other types of cells
3 stages of mitosis
1- DNA replicates,two identical chromosomes
2- one set of chromosomes is pulled to each end of the cell,nucleus divides
3- cytoplasm and cell membrane divide forming two cells
what is diffusion?
- the net movement of molecules from an area where they are at a higher concentration to areas where they are at a lower concentration.
what is osmosis?
diffusion of water from a dilute solution to a concentrated solution through a partially permeable membrane
what is active transport?
a process in which substances are moved from a more dilute solution to a more concentrated solution
two types of microscopes?
-light magniscope
- electron microscope
what is the benefit of electron microscope?
have much better magnification and resolution then light microscopes.
magnification equation?
magnification=size of image/size of real object
what is the function of the xylem
transporting water and dissolved minerals throughout the plant
what is the function of root hair cells
-allows the plant to absorb more water.
-allow a plant to take in the minerals it needs to survive.