B1 Flashcards
Osmosis
The diffusion of water molecules, from a region where the water molecules are in a high concentration to a low concentration, through a partially permeable membrane
Diffusion
The overall movement of particles from a high concentration to a low concentration
Active transport
Substances are transported passively down concentration gradients. Moved from low to high concentration.
Mitosis
Nuclear division ( type of cell division)
Stages of mitosis
The cell begins to divide
The DNA replicates to form 2 copies of each chromosome
The nuclear membrane breaks down. The chromosomes line up across the centre of the cell
One set of chromosomes is pulled to each end of the cell and the nucleus divides
The cytoplasm and cell membrane divide to form 2 identical cells
Cells
the building blocks of organisms
eukaryotic cell
Cells that have a true nucleus
Prokaryotic cell
Cells that do not have a true nucleus
What is in an animal cell?
Nucleus, cytoplasm, cell membrane, mitochondria, ribosomes
What is in a plant cell?
Same as animals plus: vacuole, cell wall, chloroplast
What is in a bacterial cell?
Cytoplasm, cell membrane, cell wall, ribosomes, chromosomes, plasmid, capsule, flagellum
Function of the nucleus
The control centre of the cell, contains DNA
Function of a cytoplasm
Where chemical reactions take place
Function of cell membrane
Controls the flow of substances into and out of the cell
Function of mitochondria
releases energy into the cell in respiration
function of the ribosomes
protein synthesis
Function of vacuole
keeps the cell turgid( filled with plant sap)
Function of chlorophyll
Absorbed light energy in photosynthesis
Function of cell wall
provides structure for the cell, made of cellulose
Function of chromosomes
carries genetic information
Function of plasmid
carries genetic information
Function of capsule
protects against phagocytosis
function of the flagellum
help the cell move
adaptations of muscle cells
contains proteins that slide over each other making fibres contracts. contain mitochondria to transfer energy. Store glycogen used in cellular respiration
Image size=
magnification x real size
DNA
deoxyribonucleic acid, the genetic code which defines life
Define gene
A short section of DNA, carrying genetic information. The basic unit of inheritance
When do animals differentiate?
Early stages of development
when do animal cells differentiate?
throughout life
Define STEM cells
Cell that have the ability to divide into 2 daughter cells that can differentiate to become specialised or more stem cells.
When does diffusion happen?
In plants: oxygen entering in a leaf
In animals: getting oxygen into the blood
