Themes of Biology Flashcards
How does the shape of the root cell relate to its function?
- Hair like structure: Increasing the SA:V ratio
- Thin cell wall: Increase the rate at which diffusion and osmosis takes place
- Large vacuole: Increase the amount of water/mineral salts it can store and pass on
- Many mitochondria: Increased release of energy during respiration to provide the energy for active transport
How does the shape of the nerve cell relate to its function?
- Axon: elongated (instead of multiple) to send electrical impulses more quickly
- Myelin sheath and Shwann cell: Acts as an electrical insulator to maintain the strength of the impulse as It passes along the axon
- Node of Ranvier: Increase the speed of impulse transmission and conserves energy for the axon
How does the shape of red blood cells relate to its function?
- No nucleus: allows extra space for haemoglobin molecules
- Biconcave shape: maximises surface area to allow for oxegyn to be absorbed quickly
- Smooth rounded edges: pass through capillaries without getting stuck
What are the seven properties of life?
- Order
- Evolutionary adaptation
- Regulation
- Energy Processing
- Growth and Development
- Responses to the environment
- Reproduction
Describe the unifying themes of organisation (3)
- New properties emerge at successive levels of biological organisation
- Structure relates to function
- The cell is the basic unit of structure and function
List the hierarchy of organisation
Earth –> Ecosystem –> Communities –> Populations –> Organisms –> Organ –> Tissue –> Cell –> Organelle –> Molecules –> Atoms
What are emergent properties?
- New properties that arise with each step upwards in the hierarchy of life owing to the arrangement and interactions of parts as complexity increases
Provide an example of how structure and function link together in an organism?
- Hummingbirds have a joint on their wing to ensure they hover near a plant
Describe the unifying theme of information:
- Life’s processes involve the expression and transmission of genetic information
- Chromosomes –> DNA –> genetic information
- Gene: discrete unit of hereditary information consisting of specific nucleotide sequence in DNA
How does DNA ensure the inheritance of genetic information? (2)
- By replicating with each division
- By carrying the instructions for making proteins and RNA
Describe the unifying theme energy and matter:
- Life requires the transfer and transformation of energy and matter
- Moving, growing, reproducing and the various cellular activities of life require energy
Describe how energy cycles through an environment:
- Energy enters into an ecosystem as light through sun and is transformed through plants performing photosynthesis where it is converted into sugars.
- The chemical energy in the food molecules is passed from producers to consumers –> Often energy is lost to the surrounding as heat when consumers work = entering as light and exiting as heat
Describe how chemicals cycle through an ecosystem:
- Plant absorbs chemicals from the air or soil and is then passed to an animal that eats the plant
- Decomposers such as bacteria and fungi that break down waste products leaf litter and the bodies of dead organisms returning the chemicals to the environment
- These chemicals are then available to be taken up by the plants again
Describe the unifying theme of interactions and provide an example:
- Interactions are important from molecule to ecosystem level
- eg. Regulation of blood sugar level: cells in the body must match the supply of fuel (sugar) to demand regulating the opposing processes of sugar breakdown and storage
What is feedback regulation and the two types?
The regulation of a process by its output or end product
- Negative feedback is a loop in which the response reduces the initial stimulus e.g. insulin
- Positive feedback is when an end product speeds up its own production eg. Blood clotting the chemicals released by the platelets attract more platelets
How have human interactions with the environment caused climate change?
- Human practices have released large amounts of carbon dioxide and other gases into the atmosphere which has trapped heat close to the Earth’s surface causing global warming
What impacts have climate change had on biological systems? (6)
- Increased susceptibility to pathogens and pests
- More often extreme weather events
- Loss of habitat for species causing a decrease in population size
- Loss of synchrony with pollinators
- Increased competition from Invasive plants
- Destabilisation of symbiotic partnerships
What is evolution?
- decent with modification
- species accumulate differences from their ancestors as they adapt to different environments over time
What caused diversity between species?
- The process of evolution
- Certain heritable changes occurred as species diverged from their common ancestor
What is unity in shared features in species due to?
Sharing a common ancestor
What is Darwin’s theory of natural selection?
- Individuals with advantageous inherited traits survive and reproduce at higher rates than others because those traits are more suited to their environment and are passed on
The shared anatomy of mammalian limbs reflects…
- Inheritance of the limb structure from a common ancestor
- the diversity of mammalian forelimbs results from modification by natural selection
Provide an example of accelerated evolution:
- Introduction of toads caused accelerated evolution for other species as they adapt to survive and outcompete eg. Crows flipping over toads
How does science benefit from a cooperative approach and diverse viewpoints?
- Biologists approach questions at different levels
- Diversity among scientists promotes progress in science
