Chapter 1 The Science of Biology 1.1 What is science 1.2 Science in context 1.3 Studying life

Bias Particular preference or point of view Very personal Should be avoided Science aims to be objective Not always possible Mitigated through collaboration

Where do ideas come from? Good scientists Curious Skeptical Open minded Creative Existing practical problems Technology Advancements in technology further scientific innovation Communication Peer reviewed work – sharing ideas, test and evaluate each others work

Science in Context How does science influence society? Scientific research is strongly influenced by societal need Provides answers to questions that affect our day to day life How does society influence science? Ethics Morality Who should pay for science? In a product safety student, who should pay for research? Companies to maintain high standards or the government to protect the people?

Why is it important to understand how science is performed and ideas are developed? Provide a critical viewpoint Helps to assess the validity of ideas Why is it important to know the limitations of Science? Important to know what questions science can’t answer

What makes something alive? Made up of basic units called cells Smallest unit considered fully alive Cells can grow, respond to stimuli, and reproduce Cells are complex and highly organised

Are based on a universal genetic code All molecules store information needed to live, grow and reproduce in genetic code Written into DNA Essentially copied and pasted from parent to offspring Almost identical for every organism on Earth

Obtain and used materials and energy All organisms grow, develop and reproduce This requires energy Energy obtained via metabolism Combination of chemical reactions through which an organism builds up or breaks down materials

Grow and develop All organisms have patterns of growth and development During development a fertilised egg continues to divide As they divide, they differentiate Look different from each other Perform different functions

Reproduce They must be able to produce new similar organims Sexual reproduction Two parents cells combine to produce first cell of new organism Asexual reproduction Single offspring produces identical cell

Respond to stimuli Stimulus - signal to which an organism will respond Organisms detect and react to stimuli from their environment Move towards food if hungry Move away from danger for protection

Change over time Groups of things will physically change or evolve over time Evolutionary theory suggests that life can be linked to a common origin very early in Earth’s history Evidence found in shared DNA between organisms Fossils Shared physical features and structures

Maintain stable environments Need to maintain stable environment despite changes in external conditions Which can sometimes be dramatic This process is called homeostasis

Key ideas Cells – cellular basis of life Heredity Energy and Matter Unicellular and multicellular organisms Many different types of cells Heredity Information coded by DNA – same for 3.5 billion years DNA makes you and all living things unique Energy and Matter Autotrophs – make their own energy from light or chemicals Heterotrophs – ingest food Growth, development and reproduction New organisms always smaller than parents Homeostasis Small variations to internal environment can often result in serious consequences

Key themes continued Evolution Structure and Function As a group living things evolve. Genetic and physical evidence Structure and Function Major groups of organisms have evolved a collection of structures that make functions possible as new environments are encountered Diversity of life Large variety of life on earth Major similarities at molecular level Explained through evolutionary theory Interdependence Everything connected on Biosphere (living planet) Dependent on cycling of matter and flow of energy Science as a way of knowing Science is not just facts! Allows people to marvel at world around Live successfully in the biosphere!

Biology is an exciting diverse subject… There are many overlapping fields that use different tools to study life from molecular level to the entire planet! Numerous different fields.. Ecology Interactions amongst organisms and the environment Environmental Science Applied part of ecology – conservation, management etc… Biotechnology Use of living systems and organisms to develop or make products – e.g. microorganisms in antiobiotic production Genomics Applies DNA sequencing methods and recombinant DNA to analyze the function and structure of genomes Molecular biology Structure and function of macromolecules essential for life – proteins, nucleic acids Zoology Structure, embryology, evolution, classification habits and distributions of all animals

Which can lead to a number of exciting different careers

A Key unifying concept is safety… All science experiments have to be conducted in a safe and professional manner Follow all instructions carefully Ensure you fully understand procedures and all safety precautions Read lab skills appendix B A-11 to A13 Before starting any lab work ensure that you understand the entire procedure

Metric system 1km – convert to metres 0.45 liter – convert to milliliters 5000 milligrams – convert to grams 130 metres – convert to kilometers 2500 mililetres – convert to liters 0.017 grams - convert miligrams

Summary Design an experiment to study how temperature affects the rate at which sliced apples turn brown Hypothesis Variables Experimental groups

Key points summarized Independent variable Dependent variable Control Hypothesis

Key summary continued Bias Ethical/moral implications of science What makes something alive? Unifying concepts in Science