Introduction To The Living Cell Flashcards
What is the smallest cell in the world? A) mycoplasma - bacteria genetelium B) human egg cell C) HIV cell - viral cell D) Granule cell
A) mycoplasma
What are the key universal features of living cells? (8 features)
- All cells have evolved from a common ancestor
- All cells communicate using receptors
- cells exchange molecules with surroundings
- All plasma membranes are made of phospholipid bilayer
- Store hereditary information as DNA
- A DNA fragment corresponding to one protein is a gene
- Translation occurs the same in all cells - sequence of codon = genetic code
- All cells are made from simple building blocks - eg. Amino acids
What is a diatom?
Microscopic single-celled Algae, where the cell walls are composed of transparent silica known as frustule.
What is the largest cell on earth?
Ostrich egg
Define Homeostasis
Ability of an organism or cell to maintain internal equilibrium by adjusting its phisiological processes.
Define a Feedback Loop
A process in which the output of a process acts back to regulate the same process.
What is negative feedback?
When the output inhibits its own production.
What is positive feedback?
The output stimulates its own production.
Describe what is meant by life being a “patter of flux”
The idea that components of cells and tissues are constantly being replaced - water is replaced most rapidly.
