Microscopy Flashcards
Many of the cell contents are…
colourless so they need to be stained to be seen.
The deeply staining material in the nucleus is…
chromatin, which is a mass of loosely coiled threads.
Chromatin collects together…
to form visible separate chromosomes during nuclear division.
The nucleolus is made of…
loops of DNA from several chromosomes. It is even more deeply staining area than chromatin.
The number of nucleoli is…
variable, one to five being common in mammals.
Organelle
Functionally and structurally distinct part of a cell. Often surrounded by membranes.
Why are many organelles surrounded by membranes?
So that their activities can be separated from the surrounding cytoplasm. This is called compartmentalisation.
Compartmentalisation is essential for a strucutre…
as complex as an animal or plant cell to work efficiently.
Division of labour means that…
work is shared between differently specialised organelles.
The most numerous organelles seen with a light microscope are usually…
mitochondria. They can move, change shape and divide.
Golgi apparatus is a part…
of complex internal sorting and distribution system within the cell.
Plasmodesmata
Fine strands of cytoplasm which pass through pore-like structures in their walls.
Phagocytic vacuoles
Small temporary vacuoles that can be found in animal cells.
The plant vacuole is surrounded by a membrane called…
tonoplast, which controls exchange between cytoplasm and the vacuole.
The fluid in the plant vacuole is…
a solution of pigments, enzymes, sugars, waste products, mineral salts, oxygen and CO2.
