Biology: Science of Life Chapter 1 Biology: Science of Life

What is Science? A verifiable process – must be testable! Evidenciary Collaborative Constantly questioning the known, the unknown, and each other Looking for, and trying to solve problems

Overview We don’t say true/false in US…we say supported or rejected as being more correct Per statistics results can never be with 100% confidence….though more support increases confidence level

Experimental Design recap Control/ Control group: comparative group; the usual conditions Experimental group: tested group; alter one condition to compare to control group Independent variable: altered factor, manipulated variable Dependent variable: measured factor, responding varibale, data collected Constant: unchanged factor(s), controlled variables

Analyze and represent data Why is this data represented by a line graph? Why not a bar graph or a pie chart? When would you use those?

Biology: Science of Life Study past, present and future life Interactions Structures Functions Solve biological problems Agriculture Disease Conservation/Remediation

What is life? We decide: Respond to Stimuli 1+ cells Use Energy Organization Grow/develop Reproduce Respond to Stimuli Use Energy Homeostasis Adapt/Genetics Humans have constructed this definition of life? What about viruses? What about evolution?

Life Traits I 1+ cells The cell is the basic unit of life What does basic unit mean? Organization Atoms->molecules->cells->tissues->organs->organ systems- >organism (assuming multicellular) How do we amend this sequence if the organism is unicellular? Grow/develop Increase cell size and/or increase cell number Go through stages of maturity Homeostasis Regulate internal conditions Ex: temp, water, blood sugar Consider an example or analogy to describe the meaning of “basic unit” Growth and development are different

Life Traits II Reproduce Respond to Stimuli Use Energy Adapt/Genetics Species = group of organisms that can interbreed to produce viable (fertile) offspring Respond to Stimuli Able to process and react to internal/external environ. Use Energy Get/make food (chemical energy) to fuel metabolism, get energy (ATP) to power processes Adapt/Genetics Change in inherited traits over time Species concept is under scrutiny because it does not always play out – what about hybrids? What is external stimuli? What is internal stimuli – think about blood sugar, temp, water balance… We will talk about ATP a lot…it is the energy currency of the cell Adaptation does not happen to individuals and time refers to generations

Details on Characteristics Cells: Unicellular Multicellular 1st life forms Evolved later 1 cell More than one cell All bacteria, all protists (euglena, ameboa, paramecium), some fungi All animals, all plants, some fungi GROW by cell enlargement only GROW by cell enlargement and cell division REPRODUCE by cell division (asexual reproduction) REPRODUCE mainly by making specialized cells that combine sexually

Details on Characteristics II REPRODUCTION: Asexual Sexual Evolved first Evolved later Unicellular organisms divide to make more identical unicellulars Multicellular organisms use meiosis to make sperm/egg One “parent” – contributes 100% of genetic info Two “parents” – each contribute 50% of genetic info Make a clone – no genetic variation between generations Genetically different offspring – more variation in population – GOOD for survivability/evolution

More on Reproduction… Bacteria (unicellular, asexual) can exchange genetic info between individuals to increase genetic variation Called “conjugation” Remember: genetic variability is a good thing for evolutionary survival!!

Details on Characteristics III Adaptation/Response Adaptation (evolution) Response (to stimuli) Long-term Short-term Population response to changing environmental conditions Immediate feedback to stimuli More genetic variability in the population = the better able the population can adapt EX: adaption as a result of changing climate – thicker fur EX: response to changing temperatures – burrow, put on a coat

Details on Characteristics III Energy use Autotrophs Heterotrophs BOTH versions of organisms convert “food” energy into ATP energy to power their cellular processes!! All plants, some bacteria, some protists All animals, All fungi, some bacteria, some protists (NOTE: some plants can do this too! “carnivorous plants –VFT!) AKA “producers” AKA “consumers” Make own food Eat other organisms or the products of other organisms Two versions: Photosynthesis Chemosynthesis

More on Autotrophy… There are two general processes: Photosynthesis use sun as energy needed to make food Chemosynthesis use chemicals as energy Hydrothermal deep sea vents

Life vs. Viruses Viruses: Bacteria, protists, fungi, plants and animals are living; viruses are NOT living things have ALL characteristics of life, viruses do not exhibit all NOTE: anything you need a microscope to see is called a “microbe”, anything that causes disease is called a “pathogen”. MOST bacteria do not cause human illness!! Viruses: are acellular do not (generally) reproduce themselves do not use energy/ have a metabolism

Chapter 1 The Study of Life 1.1 Formative Questions What is the process of change that takes place during the life of an organism? adaptation development growth maturation A B C D FQ 2

adapting to the environment displaying organization Chapter 1 The Study of Life 1.1 Formative Questions Some species of plants begin opening their flowers in the morning when they are exposed to sunlight. What characteristic of living things does this represent? acquiring energy adapting to the environment displaying organization responding to stimuli A B C D FQ 3

Chapter 1 The Study of Life 1.1 Formative Questions What process regulates an organism’s internal conditions and keeps them stable? adaptation equilibrium homeostasis metabolism A B C D FQ 4

What is a theory? 1.2 Formative Questions Chapter 1 The Study of Life 1.2 Formative Questions What is a theory? a body of knowledge about a natural phenomenon a creative tool for designing investigations a scientific inquiry that seeks to provide an explanation an explanation supported by observations and experiments A B C D FQ 5

Chapter 1 The Study of Life 1.2 Formative Questions Scientists discard observations and data that are not consistent with current scientific understanding. B A true false FQ 6

Chapter 1 The Study of Life 1.2 Formative Questions A scientist wants to report the findings from her investigations. Before her information can be published, what must it go through? forensics peer review scientific methods the metric system A B C D FQ 7

Scientific Theory Explains natural phenomenon Supported by observations/experiments Always same results Not a hypothesis Can be modified or discarded by NEW info Ex. Gravity, cells, tectonic plates Hypothesis: This is an educated guess based upon observation. It is a rational explanation of a single event or phenomenon based upon what is observed, but which has not been proved. Most hypotheses can be supported or refuted by experimentation or continued observation. Theory: A theory is what one or more hypotheses become once they have been verified and accepted to be true. A theory is an explanation of a set of related observations or events based upon proven hypotheses and verified multiple times by detached groups of researchers. A theory is not a guess, hunch, hypothesis, or speculation A theory is built upon one or more hypotheses, and upon evidence. The word "built" is essential, for a theory contains reasoning and logical connections based on the hypotheses and evidence In a strict sense, no theory is ever proven in any field, with the possible exception of pure mathematics, since new data might come along that require a change, and there are always details that haven't been tested. The biggest difference between a law and a theory is that a theory is much more complex and dynamic. A law describes a single action, whereas a theory explains an entire group of related phenomena.

Chapter 1 The Study of Life 1.3 Formative Questions When you form a logical conclusion based on your observations and what you already know, what are you making? a conjecture an inference a speculation a theory A B C D FQ 9

a testable explanation Chapter 1 The Study of Life 1.3 Formative Questions What is a hypothesis? a defined question a curious assumption a tested inference a testable explanation A B C D FQ 10

What type of discovery is a serendipitous discovery? Chapter 1 The Study of Life 1.3 Formative Questions What type of discovery is a serendipitous discovery? accidental anticipated ingenious whimsical A B C D FQ 11

Why is the metric system preferred by scientists? Chapter 1 The Study of Life Chapter Diagnostic Questions Why is the metric system preferred by scientists? Answer: Using the same system of measurements allows a scientist to repeat another’s work knowing that he or she is performing the experiments exactly the same.

What is a testable explanation? Chapter 1 The Study of Life Chapter Diagnostic Questions What is a testable explanation? observation hypothesis experiment constant A B C D CDQ 2

Which is not a characteristic of all organisms? Chapter 1 The Study of Life Chapter Diagnostic Questions Which is not a characteristic of all organisms? made of one or more cells grows and develops capable of rational thought maintains homeostasis A B C D CDQ 3

Chapter 1 The Study of Life Chapter Assessment Questions Identify the term used to describe an explanation of a natural phenomenon supported by observation and experimentation. forensics natural law theory physics A B C D CAQ 1

Chapter 1 The Study of Life Chapter Assessment Questions In a controlled experiment, which factor is changed by the experimenter? control group experimental group dependent variable independent variable A B C D CAQ 2

Look at the figure below. Why is scientific Chapter 1 The Study of Life Chapter Assessment Questions Look at the figure below. Why is scientific data often displayed in graphs? CAQ 3

Answer: Graphs help show patterns in the data and make it easier to Chapter 1 The Study of Life Chapter Assessment Questions Answer: Graphs help show patterns in the data and make it easier to understand. CAQ 4

Which is the dependent variable in this experiment? Chapter 1 The Study of Life Standardized Test Practice Which is the dependent variable in this experiment? number of days mass B A STP 5

Chapter 1 The Study of Life Standardized Test Practice Which biological science was Jane Goodall studying when she observed chimpanzees? ecology genetics animal behavior biotechnology A B C D STP 1

Chapter 1 The Study of Life Standardized Test Practice In which activity would an environmental biologist most likely be involved? genetically engineering plants finding ways to protect species preventing the spread of disease developing new medicines and vaccines A B C D STP 2

Which is an indication that an idea is based on pseudoscience? Chapter 1 The Study of Life Standardized Test Practice Which is an indication that an idea is based on pseudoscience? It brings up more questions. It causes disagreement and debate. It does not welcome scientific investigation. It does not receive acceptance by scientists. A B C D STP 3

Chapter 1 The Study of Life Standardized Test Practice Scientists use laboratory rats to test the effects of a new drug, Razatrin. What do rats in the control group receive? food containing Razatrin food without Razatrin food containing another drug food containing a variety of drugs No food A B C D STP 4