Chapter 1 Flashcards
(11 cards)
1
Q
Cell theory
A
- all organisms made of 1+ cells
- cells are the basic unit of life
- all cell are made from pre-existing cells
2
Q
Exceptions to cell theory
A
- skeletal muscle
- giant algae
- aseptate fungi
3
Q
Limitations to cell size
A
- SA:V
- need large SA to allow waste and nutrients to cross cell wall (membrane transport)
- e.g. biconcave RBC and microvilli
4
Q
Functions of life
A
- nutrition
- metabolism
- growth
- response
- excretion
- homeostasis
- reproduction
5
Q
Emergent properties
A
features that only occur by components working together e.g. organs, tissues, organ systems
6
Q
Multicellular organisms
A
a single mass of cells fused together
7
Q
Gene expression in cell differentiation
A
only express genes needed, all have full DNA but switch off certain genes to differentiate and have specific functions
8
Q
Why specialised cells
A
more economical, only use materials needed for specific function
9
Q
Stem cells
A
can differentiate to be any cell for embryonic development, found in adult bone marrow
10
Q
Uses of stem cells
A
- Stargardt’s macular dystrophy, inject stem cells into eyes to replace degenerated photoreceptor cells
- Leukaemia, extract stem cells from bone marrow, chemotherapy, return stem cells
- regenerating tissue, e.g. burn victims
11
Q
Importance of electron microscope
A
- allowed structures to be seen up to 0.001um, light microscope only 0.2um, allowed organelles and membranes to be seen
- disproved many theories
