Topic 1.1: Introduction to Cells Flashcards
What are the 3 principles of cell theory?
The cell theory states that:
- All living things are composed of cells (or cell products)
- The cell is the smallest unit of life
- Cells only arise from pre-existing cells
What are the 7 basic functions integral to survival?
metabolism, reproduction, sensitivity, homeostasis, excretion, nutrition, and growth
Define metabolism (in terms of basic functions needed for survival)
Living things undertake essential chemical reactions
Define reproduction (in terms of basic functions needed for survival)
Living things produce offspring, either sexually or asexually
Define sensitivity (in terms of basic functions needed for survival)
Living things are responsive to internal and external stimuli
Define homeostasis (in terms of basic functions needed for survival)
Living things maintain a stable internal environment
Define excretion (in terms of basic functions needed for survival)
Living things exhibit the removal of waste products
Define nutrition (in terms of basic functions needed for survival)
Living things exchange materials and gases with the environment
Define growth (in terms of basic functions needed for survival)
Living things can move and change shape or size
Which of the 7 basic functions integral to survival is: Living things undertake essential chemical reactions?
metabolism
Which of the 7 basic functions integral to survival is: Living things produce offspring, either sexually or asexually?
reproduction
Which of the 7 basic functions integral to survival is: Living things are responsive to internal and external stimuli?
sensitivity
Which of the 7 basic functions integral to survival is: Living things maintain a stable internal environment?
homeostasis
Which of the 7 basic functions integral to survival is: Living things exhibit the removal of waste products?
excretion
Which of the 7 basic functions integral to survival is: Living things exchange materials and gases with the environment?
nutrition
Which of the 7 basic functions integral to survival is: Living things can move and change shape or size?
growth
How do you calculate magnification of a drawing or image?
Magnification = Image size (with ruler) ÷ Actual size (according to scale bar)
How do you calculate the actual size of a drawing or image?
Actual Size = Image size (with ruler) ÷ Magnification
How do light microscopes work?
Light microscopes use visible light and a combination of lenses to magnify images of mounted specimens
What type of microscope uses visible light and a combination of lenses to magnify images of mounted specimens?
light microscopes
What is the organisation of multicellular organisms?
Cells may be grouped together to form tissues
Organs are then formed from the functional grouping of multiple tissues
Organs that interact may form organ systems capable of carrying out specific body functions
Organ systems collectively carry out the life functions of the complete organism
Define cell differentiation
Differentiation is the process during development whereby newly formed cells become more specialised and distinct from one another as they mature
What is the process during development whereby newly formed cells become more specialised and distinct from one another as they mature?
differentiation
What causes differentiation?
The activation of different instructions (genes) within a given cell by chemical signals will cause it to differentiate
How are active genes packaged within the nucleus?
Active genes are usually packaged in an expanded form called euchromatin that is accessible to transcriptional machinery
How are inactive genes packaged within the nucleus?
Inactive genes are typically packaged in a more condensed form called heterochromatin (saves space, not transcribed)
Define euchromatin
type of chromatin that form when active genes are packed together
Define heterochromatin
type of chromatin that form when inactive genes are packed together
What are the two qualities of unspecilised cells?
self renewal and potency
Define self renewal (in terms of unspecialised cells)
They can continuously divide and replicate
Define potency (in terms of unspecialised cells)
They have the capacity to differentiate into specialised cell types
Define stem cells
unspecialised cells