1.1 Cell Theory Flashcards
Cell theory states that…
- Cells are the basic unit of structure in all living things
- All living things are composed of cells(the smallest unit of life)
- Cells only arise from pre-existing cells
Name of the processes in which cells reproduce
Mitosis and Meiosis
How do cells multiply
Through division
All life…
Evolved from simpler ancestors
The membrane…
Contains all cell content
Function of genetic material
Instructions for cell activities
Activities are…
Cell reactions catalysed by enzymes produced in the cell
Own energy release system is
Power activities
Mitosis produces
Genetically identical diploid daughter cells
Meiosis produces
Haploid gamates (sex cells)
Exceptions to cell theory
- Striated Muscle Fibres (does not function as autonomous unit)
- Aesptate Fungal Hyphae (living structure NOT composed of discrete cells)
- Giant Algae (larger organism of only one cell)
How do Striated Muscle Fibres challenge cells theory?
Challenges idea: Cells function as autonomous unit.
Fuse to form very long Fibres and have multiple nuclei despite being surrounded by a single continuos plasma membrane
How do Fungal Hyphae challenge cell theory
Challenges idea: living structures are composed of discrete cells
How do Giant Algae challenge cells theory
Challenges idea: larger organisms are made up of many microscopic cells
Some unicellular algae may grow to large sizes
What are the functions of life
(MRS H GREN)
Metabolism
Reproduction
Sensitivity
Homeostasis
Growth
Response
Excretion
Nutrition
Metabolism
Chemical reactions within organisms
Reproduction
Producing offspring (sexually/asexually)
Sensitivity
Response to internal & external environment
Homeostasis
Maintaining & regulating internal condition (e.g temperature)
Growth
Movement & change of shape & size
Response
React to environmental changes
Excretion
Getting rid of waste products due to metabolism
Nutrition
Obtaining food to provide energy & materials for growth
Importance of SA:Vol ratio
Important to the limitation of cell size
The effects of a smaller cell
The diffusion pathway is smaller, there is less time and energy to move
When the SA:Vol ratio is larger
More efficient diffusion
The limitations of a large SA:Vol
Loses heat and water quickly
The function of Mass/Volume of cells
Controls rate of metabolism
The function of surface area of cell
The rate of material exchange
How does volume, surface and SA:Vol ratio change as cell grows
Volume increases faster than surface rea, decrease SA:Vol
What happens if metabolic rate of a cell exceeds change of materials and wastes
Low SA:Vol ratio, the cell will soon die
How do cells maintain a high SA:Vol ratio
Divide to remain small
What is needed for metabolism to preform at optimum rate
Oxygen must be absorbed and waste products removed
What does a high SA/Vol ratio achieve
Faster waste and heat removal. Faster oxygen and nutrient absorption
Conversion of mm to um and nm
mm to um = 1000
Mm to non = 1000000
Conversion of um to nm
1um = 1000nm
How to calculate image size
Actual size x magnification
How to calculate actual size
Image size / magnification
How to calculate magnification
Image size / magnification
Emergent properties
Arise from interaction of single component
S to produce new functions
Why can multicellular cells complete some functions unicellular cells cannot
New synergistic effect = Collective actions of individual cells combining
Features of multicellular organisms
Tissues, organs, organ systems and are a complete organism
How are tissues formed
When cells group
Organs formed
Functional grouping of multiple tissues
Organ systems formed
Organs that interact and carry out specific body functions
How do specialized tissues develop
Through cell differentiation in multicellular organisms
Differentiation
Process during development where newly formed cells become specialized/distinct. Expression of only some genes in genome.
Significance of identical genome
All cells of an organism share an identical genome
Steps of differentiation
Chemical signals activate different instructions within the gene, become specialized
