Cell specialisation and organisation Flashcards
How are erythrocytes adapted in terms
organelle content
shape
size
COntent- NO nucleus, increases amount of Hb
Shape- binconcave shape increases SA:V
SIze- Small enough to fit through capillaries
close to body tissues
Neutrophil adaptations in terms of
organelle content
Cytoplasm contatins small granules, some of these are lysosomes which contain digestive enzymes to digest bacteria
Sperm cell adaptations in terms
Organelle content
Size
Organelle content- acrosomes enzyme helps to penetrate through egg. mitochondria provie ATP for movement of flagella
shape- very small, long and thin to ease movement
singe long flagella helps to properl cell UP
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Definition of a tissue
A collection of cells that are similar to each other, that peform the same function
Definition of organ
A collection of tissues working together to perform a particular function
Organ system
Number of organs working together to perform and overall life function
why does differentiation in RBC imvolve a change in shape
nucleus is lost
cell has lrge SA:V
so more oxygen can be taken in and released more efficiently
How do meristem cells create xylem cells through differemtiation
Meristem cells produce cells whose walls become reinforced with deposition of lignin
this kills the contents in the cells, and breaks down the end walls, creating a continuous column
Structure of phloem
Phloem consists of sieve tubes and companion cells
CELLS LINE END TO END
SIEVE PLATES FORM BETWEEN THE CELLS
ALLOWING THE MOVEMENT OF SUBSTANCES
COMPANIONS CELLS ARE METABOLICALLY ACTIVE
Name and state the functions of the 4 main groups of tissue
Epithelial tissue- linings and layers
Muscle tissue- contraction, move parts of the body
Nervous tissue- converts stimuli into electrical impulses
connective tissue- holds (connects) structures together, provides support (CARTILAGE, BONE)
How is squamous epithelial tissue adapted for it’s function
It’s a thin smooth flat surface, in which fluids can pass easily over
It’s very thin, made of flattened cells, which reduces the diffusion distance
How is the upper epidermis, palisade cells, spongy mesophyll cells and lower epidermis adapted for photosynthesis
Upper epidermis is TRANSPARENT lets light through
Palisade cells are CYDRICAL packed with chlorophyll
LARGE vacole means chloroplasts near to cell wall short DD
Spongy mesophyll has lots of air spaces to allow circulation of gases
Lower epidermis contains stomataa whch are opened and closed by guard cells, to allow gases to diffues n and out
How do guard cells cells to open
Cell walls of guard cells are made of cellulose
water moves in making them turgid
the 2 guard cells bulge at boh ends , so stomata opens
How is locomotion an example of system co-operation
Muscular and skeletal msystems have to work together for movement to take place
NERVOUS SYSTEM instructs muscle system to co-ordinat their actions
Muscles require nurtrients and oxygen supplied by the CIRCULATORY SYSTEM
WHich receives them from the DIGESTIVE SYSTEM
