FINAL SPRING REVIEW

1. FINAL SPRING REVIEW

2. What is an investigative question? • Lisa wants to do an experiment on a hair product she’s seen advertised all over television. Rogooti claims to increase the speed of hair growth. • What should Lisa’s investigative question be? • Does Rogooti speed up hair growth?

3. What is a hypothesis? • Lisa’s investigative question is “Does Rogooti speed up hair growth?” What would her hypothesis be? • If a person uses Rogooti, then their hair will grow faster. • All hypotheses are in the “If, then” format.

4. How do you test a hypothesis? • How should Lisa test her hypothesis? • She can apply Rogooti to some members of her family (Marge and Homer) and measure the growth of their hair after a month. • How does she know that Rogooti increased the growth of their hair? • She can measure the hair growth of Marge and Homer for a month without Rogooti and compare it to the growth of their hair with Rogooti.

5. What are experimental variables? • In Lisa’s experiment what is the: • Independent variable? • Applying the Rogooti to Marge and Homer’s hair. • Remember, the independent variable is what the scientist manipulates! • Dependent variable? • The amount the hair has grown. • The dependent variable is what the scientist measures! • Control? • The measurement of hair growth WITHOUT Rogooti. • The control is something you can COMPARE the results to.

6. How do you interpret a data table? • Lisa recorded her results in this table. • What should her conclusion be? • Her conclusion should be that Rigooti works!

7. How do you graph information? • How should Lisa graph her information? • The independent variable is on the X-axis • The dependent variable is on the Y-axis • You can compare the control AND the variables by doing a multi-line graph! Lisa’s Rigooti Experiment Growth in cm

8. How do you confirm experimental data? • To confirm the results of her experiment, Lisa should… • Do the experiment again • Have more test subjects

9. How do you TRANSCRIBE DNA? • Here is a string of DNA: • DNA = C C T A C G G G A T T C • mRNA = • To TRANSCRIBE the DNA, you have to make it into mRNA. • Adenine pairs with Uracil • Guanine pairs with Cytosine • Thymine pairs with Adenine • This process takes place in the NUCLEUS! • The DNA strand is too large to leave the nucleus, but the mRNA strand can. G G A U G C C C U A A G

10. How do you TRANSLATE DNA? • Now you have your new mRNA strand! • G G A U G C C C U A A G • It is smaller than the DNA strand, and can leave the nucleus for the cytoplasm. • Once in the cytoplasm, it hooks up with a ribosome, that “reads” the mRNA strand three nucleotides at a time (a codon) with the help of tRNA. • This process is TRANSLATION.

11. aa3 3-tRNA G A A How do you TRANSLATE DNA? peptide bond aa1 ribosome aa2 1-tRNA 2-tRNA Anti-codon U A C G A U A U G C U A C U U C G A hydrogen bonds codon mRNA

12. How do you TRANSLATE DNA? • Every three nucleotides on the mRNA is a codon. • Every codon has an anti-codon that carries an amino acid! • As tRNA brings its anti-codons (and amino acids) to the mRNA strand, it builds PROTEINS! • We know which amino acids go with each codons because there is a universal code. • Our mRNA strand: G G A U G C CC U A A G • Is coding for: GGA = Glycine • UGC= Cysteine • CCU= Proline • AAG= Lysine

13. Where does transcription and translation take place? • REMEMBER: • TRANSCRIPTION is in the NUCLEUS! • TRANSLATION is in the CYTOPLASM!

14. What is the genotypic and phenotypic ratio? • A loving couple wants to have children. They are both heterozygous for brown eyes. They want a blue-eyed child. What are their chances? • Genotype • Gene combination for a trait (Bb, BB, bb) • Phenotype • The physical feature resulting from the trait. (brown eyes or blue eyes) • Mom has the genotype Bb. • Dad has the genotype Bb.

15. What is the genotypic and phenotypic ratio? • The genotypic ratio is 1:2:1 or BB : Bb,Bb : bb • The phenotypic ratio is 3:1 or brown, brown, brown : blue Mom has genotype: Bb Dad has genotype: Bb B b B B B B b b B b b b

16. What conditions promote the inheritance of genetic traits? Jaguar Fossil • Fitness • Fitness is a measure of the ability to survive and produce more offspring relative to other members of the population in a given environment. • After the climate change, jaguars that had larger teeth and jaws had a higher fitness than other jaguars in the populations. Modern Jaguar Skull

17. What is the difference between incomplete and codominance? Incomplete Dominance • The offspring will have a phenotype somewhat in between the phenotypes of the two parents. • Co-Dominance • Both alleles are expressed in the offspring. Parents: MOM DAD

18. What evidence supports evolution? • Fossils • Fossils show changes in organisms through time. • Embryology • Similar features in the embryos of different organisms suggests evolution from a distant common ancestor. • Comparative Anatomy • Homologous, analogous, and vestigial structures give a peek in to the history of changes that have occurred in organisms. • DNA • DNA studies show entire gene sequences in common between organisms. Pig Dolphin Human

19. What is comparative anatomy? • Homologous structures • Features that have SIMILAR STRUCTURES but DIFFERENT FUNCTIONS • Analogous structures • Features that have the SAME FUNCTION but DIFFERENT STRUCTURES • Vestigial structures • Remnants of structures that ONCE HAD A FUNCTION but NO LONGER DO

20. What are patterns in the fossil record? • Punctuated Equilibrium • Bursts of evolutionary activity are followed by long periods of stability. • Adaptive Radiation • The diversification of one ancestral species into many descendent species. • Extinction • Extinctions often occur when a species as a whole is unable to adapt to a change in its environment. Frilled Sharks have been around for millions of years. Anolis lizards have undergone adaptive radiation on the Caribbean Islands. The last Golden Toad was seen in 1989. It is thought that a combination of global warming and pollution lead to its extinction.

21. How do genetics support the idea of evolution? • The basic definition of evolution is a change in the gene pool of a population of organisms over time. • All of evolution is based on genetic change. • Genetic similarities between two organisms point to a common ancestor. • By following mutation rates, scientists can guestimate how far back two species diverged from a common ancestor. Bonobo Chimpanzee By looking at the accumulated mutations in the DNA of Bonobos and Chimpanzees, scientists have determined that these two species separated from a common ancestor less than one million years ago.

22. What is natural selection? • Natural selection is a mechanism by which individuals that have inherited beneficial adaptations produce more offspring on average than do other individuals. • In nature, the environment is the selective agent. • Therefore, characteristics are selected only if they give advantages to individuals in the environment.

23. What are the causes and effects of natural selection? • There are four main principles to the theory of natural selection: • Variation • Heritable differences, or variations, exist in every population • Overproduction • Organisms have more offspring than can survive. • Adaptation • Sometimes, a certain variation allows an individual to survive better than other individuals it competes against in its environment. • Descent with Modification • More individuals will have the variation in every following generation.

24. What are the causes and effects of natural selection? • Descent With Modification • Over time, natural selection will result in species with adaptations that are well suited for survival and reproduction in an environment. • More individuals will have the trait in every following generation, as long as the environmental conditions continue to remain beneficial for that trait.

25. How do new species emerge? • Isolating Mechanisms • To make new species, the gene pools of the populations must become separated. • Reproductive Isolation • Reproductive isolation occurs when members of different populations can no longer successfully mate with one another. • Behavioral Isolation • Occurs when two populations are capable of interbreeding but have differences in courtship rituals or other reproductive strategies. • Geographic Isolation • Two populations are separated by a geographic barriers such as rivers, mountains, or bodies of water. • Temporal Isolation • Two or more species reproduce at different times.

26. What are the characteristics of species? • A species is a group of organisms that breed with one another and produce fertile offspring. Chinstrap Penguin Emperor Penguin Macaroni Penguin

27. What are allele frequencies? • Genetic variation is stored in a population’s gene pool—the combined alleles of all the individuals in a population. • Different combinations of alleles in a gene pool can be formed when organisms mate and have offspring. • Each allele exists at a certain rate, or frequency. • An allele frequency is a measure of how common a certain allele is in the population.

28. How do allele frequencies change? • Mutation • A mutation is a random change in the DNA of a gene. • Recombination • Most recombination occurs during meiosis—through crossing over. • Hybridization • The crossing of two different species that share common genes.

29. How do you graph allele frequencies? • Normal Distribution • Most traits will fall under normal distribution (bell curve) • Directional Selection • When natural selection favors phenotypes at one extreme of a trait’s range. • Stabilizing Selection • When natural selection favors phenotypes in the middle range. • Disruptive Selection • When natural selection favors both extreme phenotypes, while individuals with intermediate phenotypes are selected against. Normal Directional Stabilizing Disruptive

30. How do humans influence allele frequency? • Genetic Drift • Genetic drift causes the LOSS of genetic diversity in a population. • Founder Effect • The founder effect happens after a small number of individuals colonize a new area. • Bottleneck Effect • The bottleneck effect happens when an event greatly reduces the size of the population.

31. How does the environment influence allele frequency? • Industrial Melanism • Refers to the genetic darkening of species in response to pollutants. • Originally, the vast majority of peppered moths had light coloration, which effectively camouflaged them against the light-colored trees and lichens upon which they rested. • Widespread pollution during the Industrial Revolution in England, many of the lichens died out, and the trees which peppered moths rested on became blackened by soot, causing most of the light-colored moths to die off due to predation. • At the same time, the dark-colored moths flourished because of their ability to hide on the darkened trees. • Since then, with improved environmental standards, light-colored peppered moths have again become common.

32. How does immigration affect allele frequency? • Gene Flow • The movement of alleles from one population to another is called gene flow. • For many animals, gene flow occurs when individuals move between populations. • For example: Certain birds leave their nesting areas once they are able to fly. • These birds most likely join new populations. • The alleles that these birds have then become a part of another population’s gene pool. • Gene flow increases the genetic variation of the receiving population.

33. What is the difference between biotic and abiotic factors? • Biotic • Factors that are living things, such as plants, animals, fungi, and bacteria. • Abiotic • Factors that are non-living things such as moisture, temperature, wind, sunlight, and soil. The balance of these factors determines which living things can survive in a particular environment.

34. What influences do biotic and abiotic factors have on populations? • Density-Dependent Limiting Factors • A limiting factor that depends on population size. • Usually includes biotic factors • Competition • Predation • Parasitism • Disease • Density-Independent Limiting Factors • Affect all populations in similar ways, regardless of the population size. • Usually includes abiotic factors • Fire • Drought

35. What are some differences and similarities between heterotrophs and autotrophs? • Autotrophs • Also known as producers • Organisms that get their energy from non-living resources, meaning—they make their own food. • Heterotrophs • Also known as consumers • Organisms that get their energy by eating other living or once-living resources, such as plants and animals.

36. How do you interpret a food chain? • A food chain is a sequence that links species by their feeding relationships. • This model chain only shows the connection between ONE producer and a SINGLE chain of consumers within an ecosystem. • Energy flows from PRODUCER TO CONSUMER

37. Compare a food chain and an energy pyramid. • An energy pyramid is a diagram that compares the energy used by producers, primary consumers, and other trophic levels. • As energy moves up the food chain—IT DECREASES • Those organisms at the top of the food chain, have the lease amount of energy.

38. How do biomass levels change through food webs and energy pyramids? • Biomass pyramid • Diagram that compares the biomass of different trophic levels within an ecosystem. • It provides a picture of the mass of producers needed to support primary consumers, the mass of primary consumers needed to support secondary consumers, and so on. • As you go UP the food chain biomass DECREASES 5,000 Hawks 50,000 snakes 500,000 bunnies 5,000,000 blades of grass

39. How does immigration and emmigration affect population size? • Immigration • The movement of individuals into an area. • Causes population growth. • Emigration • The movement of individuals out of an area. • Causes population decline.

40. What is carrying capacity? • Carrying Capacity (K) • The environment can only support so many individuals. • The number that represents the largest amount of individuals an environment can support at any one time is the carrying capacity. • Once populations reach carrying capacity, they undergo logistic growth.

41. What are chemical cycles? • A biogeochemical cycle is the movement of a particular chemical through the biological and geological, or living and non-living, parts of an ecosystem. • They include the carbon, nitrogen, phosphorous, water, and oxygen cycles!

42. How do humans affect the environment? • Air quality • Smog is a type of air pollution caused by the interaction of sunlight with pollutants produced by fossil fuel emissions. • Water quality • Acid rain is a type of precipitation produced when pollutants in the water cycle cause rain pH to drop below normal levels. • Chemical contaminants, raw sewage, trash, and other waste products are only a few pollutants that make their way into rivers, lakes, and aquifers all over the world.

43. How do humans influence biodiversity? • Biodiversity • The wide array and assortment of species that are found in any ecosystem. • Loss of Habitat • The loss of habitat can put species in danger of becoming extinct. • Habitat Fragmentation • Habitat fragmentation occurs when a barrier forms that prevents an organism from accessing its entire home range. • Often, habitat fragmentation is caused by the building of roadways or the harvesting of forests.

44. How do humans impact natural systems? • Urban sprawl • As cities grew larger, people moved into suburbs—urban sprawl. • Suburban growth consumes farmland and natural habitats. • Global Warming • The trend of increasing temperatures is known as global warming. • Sea level rise, global temperature rise, warming oceans, shrinking ice sheets, declining arctic sea ice, glacial retreat, ocean acidification, and an increase in extreme weather events are all consequences of global warming.

45. How do humans use renewable resources? • Resources that cannot be used up or can replenish themselves over time are called renewable resources. • Wind and solar energy are renewable resources because they cannot be used up by humans. • Other resources, such as those that come from plants and animals, can be used up, but because they could last indefinitely through re-growth and reproduction, they are renewable.

46. What are invasive species? • An introduced species is any organism that was brought into an ecosystem as the result of human activities. • Introduced species can pose a great threat to the stability of an ecosystem if they prey on or crowd out native species. Burmese pythons are an introduced species in the Florida Everglades. It feeds on small animals, such as rats, birds, raccoons, and even dogs. The same organisms that alligators feed on. Competition between the introduced and native species is fierce.

47. What are some conservation techniques? • Sustainable Practices • Sustainable development is a practice in which natural resources are used and managed in a way that meets current needs without hurting future generations. • Reforestation • Timber companies cut selected trees rather than clear cutting forests. This encourages rapid re-growth of trees, and has a minimal impact on the ecosystem. • Fishing Regulation • Rotation, gear review, harvest reduction, and fishing bans are all enforced to help fish populations replenish. • Conservation • Conservation practices focus on a few species but benefit entire ecosystems. • The listed species is often called an umbrella species because its protection means a wide range of other species will also be protected.