Presentation on theme: "Unit 1 - Introduction “bios” – life, living things, “logy” – the study of Biology - the study of life Major branches of biology: Zoology – the study of."— Presentation transcript:
1 Unit 1 - Introduction“bios” – life, living things, “logy” – the study ofBiology - the study of lifeMajor branches of biology:Zoology – the study of animalsBotany – the study of plantsMicrobiology – the study of microorganismsEcology – the study of the interaction of living organisms with one another and with the non-living part of their environmentCytology – the study of cells
2 Questions 1-3, page 6How are species related the concept of biodiversity?- Biodiversity is the variety and number of species in a given areaHow do the characteristics of living things contribute to an organism’s survival?- The cells that are the basic unit of life carry out the functions needed to support and maintain life, for which they require a continual supply of energy. The ability to respond to the environment helps an organism to avoid injury and death, as well as meet material needs. Reproduction and development enable species survival.
3 Questions 3-4, page 6Describe the relationship between cells and organisms.- All organisms are made of one or more cells, which are the functional units of life, carrying out the activities to support life.How does diversity depend on a species’ ability to reproduce?- Without the ability to reproduce, a species would become extinct, which would lead to a decrease in biodiversity.
4 Question 5, page 6You respond automatically to many different stimuli, such as loud noises. Why might a quick response to a sound be important?- A quick response could protect against hearing damage or a physical threat.
5 Questions 1-3, page 11 Describe a biological system. - A system is a group of interrelated, interacting parts that make up a whole.Give an example of how structure is related to function in living things.- Structure determines function; the snout beetle’s feet have prongs and pads to walk on both smooth and rough surfaces.Why is homeostasis essential for living things?- It enables organisms to survive in diverse and changing environments.
6 Question 4-5, page 11What is the relationship between adaptation and natural selection?Natural selection leads to different adaptations in different environmentsHow are structure and function related to adaptation?- An adaptation is a genetic change that can affect the structure of some aspect of an organism’s body and how well it functions in a given environment.
7 Questions 6 & 7, page 11How is the process of natural selection involved in evolution?Natural selection of different adaptations in different environments can lead to new species.Do you think homeostasis is necessary at the level of the single cell? Explain?- Stable conditions within a cell are necessary for the cell’s survival, whether in a unicellular or multicellular organism. If homeostasis is not maintained within a cell, cell functions can be disrupted. In turn, this can disrupt functions at higher levels of organization.
8 Questions 1-3, page 17What role do hypothesis play in scientific inquiry?A hypothesis provides a testable explanation of an observation.What is the difference between an independent variable and a dependent variable?independent variable is manipulated, a dependent variable shows the effect of that manipulation.How is the meaning of theory in science different from the everyday use of the term?A scientific theory is widely accepted explanation that is supported by evidence. In everyday language, a theory is a guess.
9 Questions 4-5, page 17 4. How are hypotheses and theories related? Hypotheses and theories are both proposed explanations for a scientific question. Observations and data collected in testing hypotheses contribute to the broader question that is addressed by a theory. A theory, in turn, provides the framework for new hypotheses.5. Give examples of different ways in which observations are used in scientific inquiry.- Scientific questions are developed from intial observations. Observations are also made to test hypotheses.
10 Question 6, page 17Why is the statement “All life is made of cells” an example of a theory? Explain.- When first proposed, the idea that all life is made of cells changed the way scientists thought about what defines an organism. Not only did it encompass all accumulated evidence, but it also provided the framework for new investigations.
11 Questions 1-3, page 23How do light microscopes differ from electron microscopes?- Light microscopes use light to view specimens , including living specimens. Electron microscopes use electrons to view specimens at higher magnifications but cannot examine living specimens.Why is computer modeling used in biological studies?To model anything that is not practical or ethical to do in the real world.How does molecular genetics add to our understanding of genes?Molecular genetics is the study of inheritance on a molecular level. DNA is the molecule that encodes genetic information. A gene is a segment of DNA.
12 Questions 4-5Viruses are smaller than cells. What types of microscopes could be used to study them? Explain.- Light microscopes are not powerful enough to clearly view viruses, so electron microscopes would need to be used.Provide an example of how technology has helped biologists gain a better understanding of life.- Answers could include imaging technologies show more details of cells, computer analysis of genes and genomes, and computer models
13 Question 6Genomics can be used to study the genetic relationships among species. Why might genomics be important for evolution research?- By comparing the genomes of different species, scientists can establish how closely related species are finding occurrences of shared DNA sequences and genes.
14 Questions 1-3, page 27Give three examples of ways in which biology can help inform everyday decisions.- Knowledge of biology can inform decisions about diet, using sunscreen, and exercise.What are some of the potential benefits and risks of biotechnology?- Benefits: treatment and prevention of disease and illness, improving crop growth.- Risks: ethical concerns, privacy, potential negative health and environmental effectsWhat are some of the unanswered questions in biology?Life on other planets, cancer cure, viruses, memory
15 Questions 4-5Scientists disagree on whether genetically modified foods are safe to eat. What type of scientific evidence would be needed to show that a genetically modified food is unsafe?- Ex: long-term feeding trials comparing health of animals that do and don’t eat GM foods. The best evidence will be collected over time with humans. Over several years, there will be more data about the health of people who eat GM foods compared with people who do not.How might your study of biology help inform you about your lifestyle choices?- A knowledge of biology helps you make informed decisions about lifestyle choices that could affect your health and quality of life and health of the environment.
16 Question 6What effects might genetically modified plants and animals have on an ecosystem if they breed with wild plants and animals?- They could decrease biodiversity and affect an ecosystem in unpredictable ways.
17 Microscope terminology Micrometers – (μm): unit of measurement used for light microscopy (millimeters are too large of a unit). 1 mm = 1000 μmResolving power: a measure of the smallest distance between two points in the image of an optical system when the two points can be distinguished as separateParfocal: microscope objectives stay in focus when magnification is changed; i.e., if the microscope is switched from a higher power objective (e.g., 40×) to a lower power objective (e.g., 10×), the object stays in focus
18 Theories in BiologyTheory: proposed explanation for a wide variety of observations and experimental results.3 important theories in biology:Alvarez TheoryTheory of Natural Selection (Evolution)Cell Theory (covered in Biology 30 in detail)
19 Alvarez Theory Developed by Luis and Walter Alvarez Explain the extinction of the dinosaurs 65 million years ago (Cretaceous-Tertiary extinction event).Small asteroid or a large meteorite impacted planet EarthCaused a great deal of smoke and dust that blocked out sunlight for possibly years, caused a “nuclear winter” effectEvidence based on high levels of rare earth element iridium found at the precise fossil layer of dinosaur extinction
21 Chicxulub CraterCrater found – off the coast of Yucatan Peninsula in Mexico called the Chicxulub Crater – 180 km across, supports Alvarez Theory
22 Alvarez Theory - continued Theory has gotten stronger support because of seismic and other dataExtinction of the dinosaurs allowed mammals to flourish (we are now in the “Age of Mammals”) – Cenozoic Era
24 Natural Selection (Evolution) Commonly referred to as “evolution”Developed by Charles Darwin – British NaturalistTerm used: “survival of the fittest”Darwin sailed the world oceans on the ship HMS “Beagle”, stopped in the Galapagos Islands (in the Pacific off the coast of Peru)Studied many organisms but most famously studies numerous species of finchesDarwin observed many different beak shapes based on the food source the finch relied on.
25 Evolution - continuedDarwin concluded that species that were the most suited for a certain environment survived and reproduceMutations in a species DNA take place over millions of years and most mutations are harmful.However, some mutations give a new species an adaptive advantage (ex: polar bears – white fur allows them to hide from prey species
26 In 1859, Darwin published his book titled “the Origin of Species” – it is one of the most famous books ever written.Evolution has grown and grown and is now at the foundation of modern biologyEvolution is one of the central, unifying theories of biological science