Unit 1 Introduction to Biology Flashcards
What are the eight Properties of Life?
These characteristics of living organisms define life:
- Order
- Sensitivity or response to stimuli
- Reproduction
- Adaptation
- Growth
- Development
- Regulation/homeostasis
- Energy processing
What does “order” mean in Properties of Life?
- Organisms are organised structures that consist of one or more cells
What does “sensitivity or response to stimuli” mean in Properties of Life?
Organisms respond to diverse stimuli
- Movement towards a stimulus = positive response
- Movement away from a stimulus = negative response
What does “reproduction” mean in Properties of Life?
Single-celled organism reproduction:
1. Duplicate their DNA – the genetic material
2. Divide the DNA equally
3. The cell prepares to divide to form two new cells
- Multicellular organisms produce specialised reproductive cells that will form new individuals
- When reproduction occurs, DNA containing genes is passed to an organism’s offspring
What does “adaptation” mean in Properties of Life
- Adaptation occurs due to evolution by natural selection, which operates in every lineage of reproducing organisms
- Adaptations enhance the reproductive potential of the individual exhibiting them, including their ability to survive to reproduce
What does “regulation/homeostasis” mean in Properties of Life?
- Homeostasis refers to the relatively stable internal environment required to maintain life
- Cells require appropriate conditions (temperature, pH, concentrations of diverse chemicals)
- Organisms are able to maintain homeostatic internal conditions within a narrow range almost constantly by activation of regulatory mechanisms
What does “energy processing” mean in Properties of Life?
- All organisms use a source of energy for their metabolic activities
e.g. taking energy from the Sun and converting into chemical energy in food
What does “growth and development” mean in Properties of Life?
- Organisms grow and develop according to specific instructions coded by their genes
- These genes provide instructions that will direct cellular growth and development
What is an atom?
- The atom is the smallest and most fundamental unit of matter that retains the properties of an element
- The atom has a nucleus surrounded by electrons
- Atoms form molecules
What is a molecule?
A molecule is a chemical structure consisting of at least two atoms held together by a chemical bond.
What are macromolecules?
Macromolecules are large molecules that are typically formed by combining smaller units called monomers.
What are organelles?
- Organelles are small structures that exist within cells and perform specialised functions
- They contain aggregates of macromolecules surrounded by membranes
What is a prokaryotic cell?
Prokaryotes are unicellular organisms that lack organelles surrounded by a membrane and do not have nuclei surrounded by nuclear membranes.
What is a eukaryotic cell?
Eukaryotic cells are organisms that have membrane-bound organelles and nuclei.
What are organs?
Organs are collections of tissues grouped together based on a common function
What is an organ system?
An organ system is a higher level of organisation that consists of functionally related organs
What is a population?
A population is all the individuals of a species living within a specific area
What is a community?
A community is the set of populations inhabiting a particular area
What is an ecosystem?
An ecosystem consists of all the living things in a particular area together with the abiotic, or non-living, parts of that environment
What is the biosphere?
The biosphere is the collection of all ecosystems, and it represents the zones of life on Earth
What are the eight levels in the taxonomic system?
Lowest to highest: species, genus, family, order, class, phylum, kingdom, domain
What are the three domains of life?
Eukarya, Archaea, Bacteria
What does the domain Eukarya contain?
Eukarya contains organisms that have cells with nuclei, this includes the kingdoms of fungi, plants, animals and several kingdoms of protists
What is the domain Archaea?
Archaea are single-celled organisms without nuclei and include many extremophiles that live in harsh environments
