Part 2 - What Makes Up An Organism Flashcards
What are cells?
They are the basic structural and functional unit of all organisms. Cells may exist as independent units of life or may form colonies (multicellular) or tissue to form plants or animals
Cells are classified into two types. Can you name these?
Prokaryotic cells and eukaryotic cells
Which cell type was thought to be the first life form on earth?
Prokaryotic cells specifically bacteria
What chemicals make up a standard human?
Carbon Nitrogen Water Phosphorus Iron 20 other elements
From what we know when were microscopic organisms/ cells first discovered? And who discovered them?
1964
By a Dutch man named Antoni van Leeuwenhoek
How long have microscopes been around?
1600’s
What enabled van Leeuwenhoek to see animalcules?
He designed and made his own lenses by curving them (more than anybody else could) which magnified up to 500 times the actual size
What did van Leeuwenhoek discover?
Van Leeuwenhoek discovered ‘animalcules’ small single celled organisms that live in water, known today as Protists. At the time however he didn’t recognise them as such - he thought they were miniature versions of the animals we see day to day
From what observations did Robert hook define cells?
Observation of self contained units in cork led to Hooke defining cells
Why could Hooke initially not see the animalcules that van Leeuwenhoek observed and described?
His microscope was not powerful, but he was able to observe animalcules he managed to increase magnification
What pioneering discovery made by Robert brown in 1830?
He discovered that cells he observed contained a nucleus
Apart from cell theory what else did Robert brown discover?
Brownian motion - the movement of particles within pollen grains
What did the scientists Schwann and schleiden discover?
They both discovered that both plants and animals are made up of a cell and that these cells contain and nucleus.
What breakthrough in cell biology did the scientist Remak make?
That all cells make cells. The divide in to two and replicate. Essentially this was the start of embryology I.e the fact that a sperm cell and an egg cell fuse to form a single cell. The single cell then divides in to two cells then these two cells divide in to 4 cells and so on.
What is the outer boundary of a cell called?
The cell membrane
What is the main function of the cell membrane?
It’s main function is to keep the cell contents separate from the external environment and at a fairly constant concentration
It also restricts the movement of molecules from inside the cell to the outside and vice versa, so effectively acting as a barrier
What is the concentration of a liquid defined as?
The concentration of a liquid is defined as the number of particles within a particular volume
What is the gelatinous of jelly like liquid inside of a cell called?
Cytosol or cytoplasm
Why does the vicious internal environment of a cell need to be maintained?
To allow metabolism (the chemical processes) within the cell to occur
Define the term metabolism?
All the chemical processes by which cells produce the energy and substances necessary for life. Food is separated into the parts it is made up of to produce heat and energy and to help with growth of the cell.
