Stuff you need to know…

1. Stuff you need to know…

2. Genetics • Meiosis- cell division that forms gametes (sex cells sperm or egg) • Will form 4 genetically different cells • Haploid- 1 copy of the chromosomes (gametes), human haploid #= 23 • Diploid- 2 copies of the chromosomes (all the rest of your cells), human diploid #= 46

3. Homologous pairs- one chromosome from mom and one from dad (PROPHASE I) • Crossing over- homologous pairs touch during meiosis and swap DNA, increases genetic diversity (PROPHASE I)

4. Chapter 11

5. Gregor Mendel- Father of Modern genetics, known for his work with pea plants • Genes- sequences of DNA that code for proteins (Ex: flower color or hemoglobin) • Alleles- forms of the gene; specific instructions (Ex: “normal” hemoglobin or “mutated” hemoglobin; “A” or “a”) • Genotype- inherited genetic make-up (AA, Aa, or aa) • Phenotype- what you physically express (normal vs mutated; purple vs white flowers; tall versus short pea plants)

6. Homo = same • Homozygous dominant- AA • Homozygous recessive- aa • Hetero= different • Heterozygous- Aa • Punnett squares- uses parent’s gametes to predict probable genetic outcomes of offspring

7. Round (R) is dominant over wrinkled (r) seeds. Cross 2 heterozygous pea plants for seed shape. • What are the chances the offspring will express the recessive trait?

8. Dad is heterozygous and mom is homozygous recessive. What are the chances their offspring will express the dominant trait?

9. Sex-Linked Genes: genes that are on the X or Y chromosome *because any gene on the Y chromosome will always affect males & only males, these problems only discuss genes on the X chromosome *females have 2 X chromosomes & males have 1 therefore, males are more likely to exhibit recessive phenotypes from sex-linked genes

10. TERMS TO KNOW!! ·EVOLUTION: cumulative change in the heritable characteristics of a population (“CHANGE OVER TIME”) ·FITNESS: refers to traits and behaviors of organisms that enable them to survive and reproduce

11. ·ADAPTATION: any inherited characteristic that enhances an organism’s ability to survive and reproduce in that particular environment ~based on variations randomly inherited (mutation & meiosis)

12. Charles Darwin’s Explanation on Evolution (six major ideas of Darwin) Not all organisms can survive Overproduction occurs in nature Variation occurs in all populations Variations are inherited Organisms with favorable variations survive and reproduce Populations as a whole become FIT = evolved!

13. Insecticide applied

14. Genetic Drift Changes in the gene pool (# or % of “A” allele vs “a” allele) of a small population due to chance; REDUCES VARIATION Examples: -Bottleneck Effect: results from drastic decrease in population size -Founder Effect: few individuals in a population colonize a new habitat

15. Bottleneck Effect

16. Speciation The origin of new species (the appearance of new species is the source of biological diversity) • Reproductive Isolation: barriers that prevent members of two species from producing viable, fertile hybrids

17. Geographic Isolation: Gene flow between gene pools is interrupted when a population is divided into two geographically isolated subpopulations • Ex: the water level in a lake decreases • Ex: a river splits a population into two

18. Ecology

19. 1) Life is ORGANIZED on many structural levels: Atoms Biological Molecules Subcellular organelles Cells Tissues Organs Organ Systems Complex Organism

20. Levels beyond the individual organism: Population Community Ecosystem Biomes Biosphere

21. Biodiversity • Definition: the number and variety of organisms found within a specified geographic region • affected by alterations of habitats.

22. fluctuations in population size in an ecosystem are determined by the relative rates of birth, immigration, emigration, and death. • Change in pop size = [B + I] – [D + E]

23. Review • Autotrophs—capture energy from sunlight or chemicals and use that energy to produce food • AKA producers • Photosynthesis • Plants • Chemosynthesis • Bacteria

24. Heterotrophs (Consumers) • Herbivores • Carnivores • Omnivores • Detritivores • Feed on plant and animal remains (have a mouth; ingest food) • Mites, earthworms, snails • Decomposers • Break down organic matter • Bacteria and fungi

25. Flow of Energy Energy flows through an ecosystem (a section of the biosphere) from the sun, to producers, to consumers IN ONE DIRECTION!!!

26. Food Chains • Food Chain—transfer of energy by eating and being eaten

27. Food Webs • Food Web—describes complex relationships of organisms in an ecosystem • A food web links together all the food chains in an ecosystem

28. Energy Pyramid Tertiary Consumers Primary Consumers • each step of an organism eating another organism is called a trophic level (trophe means food in Greek) • Shows the relative amounts of energy contained within each trophic level in a food chain or food web • Only part of the energy that is stored in one trophic level is passed on…(10%) Producers

29. Approximately 10% of the energy at one trophic level can be used by animals at the next trophic level • ex: 90% of produced/consumed energy is used in that organisms cellular respiration • Only 10% incorporated into tissues

30. More energy efficient to eat producers • Although energy moves in a one-way direction through an ecosystem, nutrients are recycled

31. Succession • series of changes in an ecological community that occur over time after a disturbance • Primary: have to make soil • Secondary: have soil; start from there

32. Fossils-Any preserved evidence of life from a past geological age (ex: impressions & remains of organisms embedded in stratified rocks; mineralized remains of an animal or plant Fossils include shells, imprints, burrows, and organically-produced chemicals. The oldest fossils are of bacteria (prokarytotes) & they are 3.8 billion years old.

33. Bacteria vs.Virus