Exam 1 Study Guide PDF

**PPT Lecture Ch 1:** Understand what is biology and how we study it Biology is the scientific study of life. We study organisms, living and fossil. Be able to list and define each major characteristic of life All organisms are made of cells, they can reproduce, ( sexually and asexual) maint...

**PPT Lecture Ch 1:** Understand what is biology and how we study it Biology is the scientific study of life. We study organisms, living and fossil. Be able to list and define each major characteristic of life All organisms are made of cells, they can reproduce, ( sexually and asexual) maintain homeostasis( regulate), use energy ( ATP to do work) and respond to their environment ( stimuli) How are nucleic acids related to living organisms and what are they used for Nucleic acids are required for reproduction and increased complexity (e.g. DNA) Know the general differences between eukaryotes and prokaryotes Eukaryotes have a nucleus and membrane bound organelles, prokaryotes do not have a nucleus or membrane bound organelles For the life history of Earth know: o The general timeline (you do not need to know specific dates) 1\. Earth formed \~4.6 billion years ago\ 2. Life formed \~4 billion years ago\ 3. Humans appeared \~2 million years\ ago o Key events and what they resulted in/from 1. Great Oxidation Event \~2.1bya Photosynthesis exploded and produced tons of O2 2. o How key events relate to living organisms Understand the difference between photosynthesis and aerobic respiration and the impact these metabolic pathways had on Earth & living organisms photosynthesis and aerobic respiration are interlinked processes that support life on Earth. Photosynthesis produces the oxygen and organic compounds necessary for life, while aerobic respiration utilizes these compounds to release energy. Together, they drive the flow of energy and carbon through ecosystems, influencing atmospheric composition and supporting diverse forms of life. Know how to read a phylogenetic tree and understand what it is used for A phylogenetic tree illustrates the evolutionary histories of different groups Trees are built by analyzing and quantifying similarities and differences among species, including genome sequences Can give supercomputers large DNA sequences from different species and it will attempt to make trees **PPT Lecture Ch 4:** Know the general structure of DNA, RNA, and nucleotides DNA- Double helix contains deoxyribose RNA- single stranded, contains ribose Nucleotides, contains a nitrogen base pentose sure and a phosphate group o Do not need to know the chemical line structure Know the structure of DNA and how it relates to shape o Which bases are purines? Adenine and Guanine o Which are pyrimidines? Cytosine and Thymine o How do purines and pyrimidines relate to one another? Purines pair with pyrimidines by hydrogen bonds. Know how DNA and RNA differ and be able to tell the difference between the two Understand the flow from DNA to proteins **Transcription**: DNA is transcribed into mRNA, which carries the genetic information from the DNA in the nucleus to the cytoplasm. **Translation**: The mRNA is translated into a protein by ribosomes, with tRNA molecules delivering the appropriate amino acids to build the polypeptide chain. **DNA**: Contains the genetic blueprint for proteins. Each gene in DNA corresponds to a specific protein or polypeptide. o What are the steps o What is the general function of each step/each molecule What are the different types of nucleic acids and what are they used for DNA: Structure: Double-stranded helix. Function: Stores and transmits genetic information, serves as a template for RNA and protein synthesis. RNA: Structure: Single-stranded. Types: mRNA (carries genetic code), tRNA (transports amino acids), rRNA (component of ribosomes), snRNA (involved in splicing), miRNA and siRNA (regulate gene expression), lncRNA (regulates various cellular processes). For each major experiment know the following: 1. People once thought that some forms of life arose from decaying matter by spontaneous generation.- Francesco Redi 2. Experiments by Louis Pasteur showed that microorganisms can arise only from other microorganisms. But these experiments did not prove that spontaneous generation had never occurred.- LP 3. Miller-Urey Experiment 1953\ 1. Set out to test the Oparin-Haldane theory in real-time\ 2. Sealed gases found in early Earth's atmosphere and added electrical sparks\ 1. Sparks simulated lightning strikes\ 2. A collecting vat was placed at the bottom to collect samples\ 3. After a few days & weeks the collection vat was emptied and paper chromatography was conducted\ 1. We don't use paper chromatography anymore but it separates the solution based on polarity\ 4. 5 amino acids were present!\ 1. In 2007 the same vials used were examined again and 20 amino acids were found o Why the experiment was done o How the experiment was set up o What were the results o Why were the results important/what did the results provide evidence for? **PPT Lecture Ch 19:** Know what evolution is, who defined it, and the major tenets Charles Darwin defined it, Evolution is how organisms change over time. What is the difference between natural selection and descent with modification natural selection is one of the processes driving descent with modification, which is the broader concept explaining how evolution occurs through inherited changes. Know the different components of natural selection and how they relate to variation - **Variation**: Provides the genetic diversity necessary for natural selection to operate. - **Inheritance**: Ensures that beneficial traits can be passed to future generations. - **Differential Survival and Reproduction**: Drives the increase in frequency of advantageous traits. - **Adaptation**: Results from the accumulation of favorable traits within a population over time. In essence, variation is the starting point for natural selection. It is the diversity of traits within a population that natural selection acts upon, leading to adaptations that enhance the fitness of organisms in their environment. Be able to differentiate between the major types of selection  **Directional Selection**: Favors one extreme phenotype, shifting the trait distribution toward that extreme.  **Stabilizing Selection**: Favors intermediate phenotypes, reducing variation around the average trait value.  **Disruptive Selection**: Favors extreme phenotypes at both ends of the spectrum, increasing variation and potentially leading to speciation.  **Balancing Selection**: Maintains genetic diversity within a population by favoring the presence of multiple alleles through mechanisms like heterozygote advantage or frequency-dependent selection. Know what traits are, the different types of traits, and how they relate to natural selection Different traits allow an organism to survive better than others Beak shape, Drought tolerance, Venom potency, Natural selection is the theory that only the best adapted to their environment will survive and reproduce. traits that enhance an organism\'s ability to survive and reproduce are favored, leading to changes in the population over time. Traits that do not provide an advantage or are neutral may persist due to other evolutionary mechanisms or genetic variation. What is genetic drift and how does it work? Genetic drift is random changes in allele frequency, it has the strongest affect on small populations, Bottleneck event , When some event greatly reduces population size, A lot of alleles are lost and variation decreases. Be able to calculate HWE p2 + 2pq + q2 = 1 o The math will be simple o No calculator required but you are allowed to use one Understand how and why we use HWE The Hardy--Weinberg equilibrium describes a perfect situation in which allele frequencies do not change ♣ Can use this equation to predict expected genotype frequencies ♣ HWE is a very powerful tool but assumes a few things. How does evolution function and why can it not produce perfect organisms? evolution shapes organisms to be well-suited to their current environments but does not aim for perfection. It operates within the constraints of existing genetic variation and environmental conditions, resulting in adaptations that are often good enough rather than perfect.