The Science of Biology

1. The Science of Biology Chapter 1

2. What Is Science? Science - a study of the natural world; to understand how it works

3. Thinking Like a Scientist Observations – using the senses to gather observations about something in the natural world Data – those observations become data when in a controlled exp Inference – a logical and rational conclusion based on prior knowledge Hypothesis – a possible answer to a question at hand; usually based off prior information; must be testable

4. Scientific Method An Organized way to solve a problem using a series of steps

5. Scientific Method Question Hypothesis (If…then..) Variables – manipulated and responding Materials Procedure Observations/Data/Graphs Conclusions/Discussion

6. Forming a Hypothesis Done after initial observations Based off of prior knowledge; logical inferences or imaginative guesses Can a group of scientist have competing hypothesis? Do all hypotheses have to be correct?

7. Forming a Hypothesis Spontaneous generation – life arising from non-life Prior to Louis Pasteur in 1881, it was the most common belief of how life arose

8. Francesco Redi’s experiment Rejected spontaneous generation and opted for biogenesis Thought that flies laid eggs on raw meat, producing the maggots that were seen a few days later

9. Francesco Redi’s experiment Controlled exp- only one variable is changes at a time and all others are Kept constant. Controlled variables: jars, type of meat, location, temp, time Manipulated variable – gauze covering or not covering the jars Responding variables: whether maggots appear

10. Needham’s Test of Redi’s Findings wanted to disprove Redi’s exp Said that Spontaneous Generation could occur under right conditions Sealed a bottle of gravy and heated it Claimed heat killed any living thing in gravy After several days found it swarming with activity/life

11. Spallanzani’s Test of Needham’s Experiment • Produced different results. Why? • Needham didn’t boil long enough • Needham didn’t seal the flask fast enough • Needham also claimed that air was necessary for life even life formed from SG • So what was found in air that Spallanzani didn’t know about?

13. Louis Pasteur Solved the problems experienced with Needham and Spallanzani Designed a flask that had a long curved neck; opened to air Microorganisms from air did not make their way through the neck into flask Showed as long as broth was protected from micro., it remained free of living things After yr broke flask and micro. Quickly appeared

14. Louis Pasteur Exp

19. Anton Van Leeuwenhoek Perfected first scientific microscope in 1673 Simple in design, but allowed him to see microorganisms for first time Called them “animalcules”

20. Leeuwenhoke time vs. Our time At time of Van L. only 2 kingdoms: animal and plant Under our six kingdom classification system, they could belong to any of them: Eubacteria, archaebacteria, Protista, Fungi, Plantae, and Animalia

21. Theory Theory - a well supported hypothesis; the highest level of “proof” in the scientific world; there are no absolutes in science So why do people often refer to theories in a neg. connotation; as not having enough evidence or support?

22. Studying Life Biology – the study of life; the science that seeks to understand the living world Is it easy to determine what is alive and not? Many living and nonliving things share same characteristics Toys, cars, clouds move whereas trees, mushrooms live in one spot

23. Living Things • Share the following characteristics • Made up of cells – multicellular and unicellular • Able to reproduce – asexual and sexual • Based on a universal genetic code • Grow and develop • Obtain and use materials and energy – metabolism • Respond to their environment • Maintain a stable internal environment – homeostasis • Change over time - evolution

24. Cells Paramecium w/ cilia, flagella Human cheek cells Everything on earth is made up of atoms; tiny balls of charged particles But only living things have organized those atoms to for proteins, lipids, nucleic acids, etc to make cells

25. Reproduction How org produce new organisms 2 basic types: asexual & sexual Sexual repro – cells from two diff parents unite to produce first cell of new org Asexual repro – now org has a single parent; hydra

26. Genetic code Deoxyribonucleic Acid (DNA) – what allows us to be different from other sp, from each other; allows us to think, talk, walk, breathe, have immunity against disease

27. Growth and Development Every org grows and develops from the moment they are conceived Newborn has already grown for 9 months Babies start out as balls of cells and eventually develop into babies we see in the world Adults still grow things like muscle, hair, fat, etc

30. Materials and energy Every org must eat; without food you die Org use a lot of energy and nutrients every day If not replenished, then org cannot function correctly and will eventually die

31. Response to Environment We all respond to changes; whether big or small Small changes include widening of pupil in low light to allow you to see better Large changes include evolving thicker fur to deal with dropping temps The bigger the change the more time it takes usually

32. Internal Balance In mammals, internal body temp must be maintained in order to survive If body temp drops too much, must be reheated or die of hypothermia “cold-blooded” org like lizards also have an internal envi; their bodies allow for a wider temp range, but cannot survive outside of that range In order to maintain internal body temp, must expend greater amount of energy

33. Evolution We all grow old Our sp is continually evolving, never stopping

35. Branches of Biology Parisitology – study of parasites and parasitism Pathology– study of diseases and the causes, processes, nature, and development of disease Neurobiology – study of nervous system, including anatomy, physiology, even pathology Mycology – study of fungi

36. Branches of biology Histology – study of cells and tissue, a microscopic branch of anatomy Evolutionary Biology – study of the origin and decent of sp over time Ecology – the study of the ecosystem as a complete unit, with an emphasis on how sp and groups of sp interact with other living beings and non-living elements Anatomy – study of the animal form, with an emphasis on human bodies

37. Branches of Biology Cryobiology – study of the effects of lower than normally preferred temps on living beings Entomology – study of insects Genetics – study of genes and heredity

38. Levels of Organization Some fields focus on the study of living systems at different levels of organization Molecular biologists and cell biologists study some of smallest living systems. Population biologists and ecologists study some of largest

39. Levels of Organization Biosphere – part of Earth that contains all ecosystems Ecosystem – community and its nonliving surroundings Community – populations that live together in a defined area Population – group of org of the same sp in the same area Organism – individual living thing Groups of cells – tissues, organs, and organ systems Cells – Smallest fx unit of life Molecules – groups of atoms; smallest unit of most chemical compounds

40. Aspect of life influenced by Biology!!!

41. Homework Read pg 23 #1-3

42. Conflicts in Science Can occur at any level of Science Even among the most respected scientists in the world Sir Richard doll and Monsanto Corporation

43. Moral and Ethical Guidelines Scientists must follow some moral and ethical guidelines when designing an ex You can’t infect people with a fatal disease You can’t perform actions that put the participants in unnecessary harm or pain No animal cruelty If a participant in your study wants to leave, they can do so w/o any reprecussions

44. Moral and Ethical Guidelines 5) Participants must be fully informed prior to enrolling in a study 6) Participants must fully understand what is going to happen during the study; those with diminished capacity must be represented by appropriate legal guardians 7) Will the study provide useful info 8) All groups of people are equally represented

45. Moral and Ethical Guidelines Patient rights have not always been observed US gov’t and the infamous Tuskegee Study

46. Tuskegee Study 40yr study Tracked 600 African American Males in deep south Started after Great Depression; low on funds Track untreated syphilis (a bacterial infection usually transmitted during sexual contact; may also be transmitted from mother to child during birthing process)

47. Tuskegee Study Can be cured with Penicillin Despite knowledge of cure, researchers failed to inform participants Participants never told of study, instead they were bribed into yearly medical exams In end, several male participants died as well as infected family to disease Deaths were preventable, but due to “science” were not Treated as test subjects not humans

48. Tuskegee Study As a result organizations were formed to mandate and standardize the human and animal test subject rights

49. Belmont Report • 1979 “Ethical Principles and Guidelines for the protection of Human subjects of Research” • 3 fundamental ethical principles for using humans for research • Respect for persons; protecting the autonomy of all people and treating them with courtesy and respect and allowing for informed consent

50. Belmont Report 2) beneficence: maximizing benefits for the research project while minimizing risks to the research subjects 3) Justice: ensuring resonable, non-exploitative, and well considered procedures are administered fairly (the fair distribution of costs and benefits