Studied by 2 peopleexponential growth
a fast increase in population size, proportional to the current population. It happens when resources are abundant and environmental conditions are favorable. But, it's not sustainable in the long term because of limited resources and increased competition.
Logistic Growth
a type of population growth in biology that occurs when a population's growth rate slows or stops following a period of exponential growth. This is due to limiting factors such as food availability, space, and competition. The population eventually reaches a carrying capacity, which is the maximum number of individuals that the environment can support.
limiting factor
environmental factors that restrict the growth, abundance, or distribution of an organism or a population of organisms in an ecosystem. These factors can be biotic (e.g. competition, predation, disease) or abiotic (e.g. temperature, water availability, nutrients) and can vary depending on the species and the ecosystem.
density dependent
the phenomenon where the growth, survival, and reproduction of a population are affected by the density of individuals in that population. This means that as the population density increases, the effects of density-dependent factors such as competition for resources, predation, and disease become more pronounced, leading to a decrease in population growth rate.
density independent
factors that affect the growth or survival of a population regardless of its size or density. These factors can include natural disasters, climate change, and human activities such as pollution.
foodwebs
diagram that shows the feeding relationships between different organisms in an ecosystem. It consists of interconnected food chains and helps to illustrate the complex interactions between species. In a food web, producers (such as plants) are at the bottom, followed by primary consumers (herbivores), secondary consumers (carnivores that eat herbivores), and so on. At the top of the food web are apex predators, which have no natural predators of their own. Food webs are important for understanding the flow of energy and nutrients in an ecosystem.
Keystone Species
A species that plays a crucial role in maintaining the structure and function of an ecosystem.
EX: The sea otter is a keystone species in kelp forest ecosystems
Ecological Pyramids
Diagrams that represent the flow of energy or biomass through trophic levels in an ecosystem.
10% Energy Rule: Only about 10% of the energy available at one trophic level is transferred to the next level.
Trophic Levels
Each level represents a group of organisms that share the same position in the food chain.
Symbiosis
Close and long-term interactions between different species.
Mutualism (both species benefit), commensalism (one species benefits, the other is unaffected), parasitism (one species benefits, the other is harmed).
Group Behavior and Survival Value
The advantage gained by a population through cooperative behaviors.
Schooling fish, flocking birds, pack hunting in wolves.
Population
A group of individuals of the same species living in the same area
Population Density
The number of individuals per unit area or volume in a population.
Exponential Growth Curve
A graph that represents rapid and continuous population growth over time.
Carrying Capacity
The maximum population size that an environment can sustainably support.
Ecosystem
A biological community of interacting organisms and their physical environment.
Biodiversity
The variety of life forms within an ecosystem, including species diversity, genetic diversity, and ecosystem diversity.
Trophic Cascade
An ecological phenomenon in which changes in the population size of a top predator cause a chain reaction of effects throughout the ecosystem.
What is a calorie?
A unit of measurement for energy. It represents the amount of energy needed to raise the temperature of 1 gram of water by 1 degree Celsius.
What is the chemical formula for glucose, oxygen, water, and carbon dioxide?
Glucose: C6H12O6
Oxygen: O2
Water: H2O
Carbon Dioxide: CO2
What is a biomolecule?
A biomolecule is a molecule that is essential for life, such as carbohydrates, lipids, proteins, and nucleic acids.
What elements make up proteins, lipids, and carbohydrates?
Proteins: Carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur.
Lipids: Carbon, hydrogen, and oxygen.
Carbohydrates: Carbon, hydrogen, and oxygen.
What is the monomer of protein
Amino acids
What is the monomer of lipids
Fatty acids
What is the monomer of carbohydrates
Monosaccharides (such as glucose)
What biomolecule is nitrogen a part of?
Proteins and nucleic acids (DNA and RNA).
Why are enzymes so important?
Enzymes are biological catalysts that speed up chemical reactions in living organisms. They are essential for metabolism and various cellular processes.
Molecules are made of what two main parts?
Atoms and bonds.
Which part of a molecule stores the energy that an organism uses?
Chemical bonds, specifically the bonds between atoms.
What is ATP, and where in ATP is energy stored? A-P-P-P
ATP (adenosine triphosphate) is a molecule that stores and transports energy in cells. Energy is stored in the high-energy phosphate bonds between the phosphate groups
What happens to the CO2 from cellular respiration?
Carbon dioxide (CO2) is produced as a waste product during cellular respiration and is expelled from the organism.
When does fermentation occur?
Fermentation occurs when oxygen is not available for cellular respiration, typically in anaerobic conditions.
Why can't an organism survive with just fermentation?
Fermentation is an inefficient process that produces a limited amount of ATP. Organisms require cellular respiration to generate sufficient energy for their metabolic needs.
What are isotopes?
Isotopes are atoms of the same element that have a different number of neutrons, resulting in variations in atomic mass.
How old is our earth?
Approximately 4.5 billion years old
What is the ultimate source of energy for life on earth?
The Sun.
What is the source of light used in photosynthesis?
Sunlight is the primary source of light used in photosynthesis.
What is the difference between a biotic and an abiotic factor?
Biotic factors: Living components of an ecosystem, such as plants, animals, and decomposers.
Abiotic factors: Non-living components of an ecosystem, such as temperature, sunlight, and soil.
What is biodiversity?
Biodiversity refers to the variety of life forms, including species diversity, genetic diversity, and ecosystem diversity, within a given area.
What are the biogeochemical cycles we learned about?
The major biogeochemical cycles include the carbon cycle, nitrogen cycle, water cycle, and phosphorus cycle.
What is carbonic acid, and why is it a problem?
Carbonic acid is formed when carbon dioxide dissolves in water, resulting in increased acidity. It contributes to ocean acidification, which can have detrimental effects on marine organisms and ecosystems.
What is one problem that can result from nutrient runoff?
Nutrient runoff can lead to eutrophication, where excessive nutrients, such as nitrogen and phosphorus, cause algal blooms and oxygen depletion in aquatic ecosystems.
We know that a leaf needs 3 things to complete the process of photosynthesis. What are these 3 things?
sunlight, water, and carbon dioxide.
What gas does the leaf give off into the air during photosynthesis?
The leaf gives off oxygen gas (O2) into the air during photosynthesis.
When you see arrows in a diagram (especially in science), what can you expect the diagram to show?
Arrows in a diagram typically represent the flow or transfer of something, such as energy, matter, or information.
How many atoms or molecules are created by photosynthesis and cellular respiration?
Photosynthesis and cellular respiration maintain a balanced exchange of atoms and molecules, resulting in no net creation or destruction of atoms or molecules.
How many atoms or molecules are destroyed during photosynthesis and cellular respiration?
none
How is the carbon cycle related to climate change? What activities concerning the carbon cycle are contributing to climate change?
The carbon cycle involves the movement of carbon between the atmosphere, land, oceans, and living organisms. Human activities, such as burning fossil fuels and deforestation, release excessive carbon dioxide into the atmosphere, contributing to the greenhouse effect and climate change.
Why are coral reefs important? Why are they diminishing?
Coral reefs are important because they support a diverse range of marine life, provide coastal protection, and contribute to the overall health of ocean ecosystems. However, they are diminishing due to factors such as coral bleaching caused by rising sea temperatures, ocean acidification, pollution, and destructive human activities.
How do we determine the age of fossils and things that used to be alive?
The age of fossils and artifacts can be determined through various methods, including radiometric dating (using the decay of radioactive isotopes), carbon dating (using the decay of carbon-14), and relative dating techniques based on the position of the fossils or artifacts in the rock layers.
What is a half-life?
A half-life is the time it takes for half of the radioactive substance to decay or transform into another element. It is a characteristic property of radioactive isotopes and is used in radiometric dating techniques.A half-life is the time it takes for half of the radioactive substance to decay or transform into another element. It is a characteristic property of radioactive isotopes and is used in radiometric dating techniques.
How would you define evolution
Evolution is the process of change in species over time, resulting in the development of new forms of life from common ancestors.
What are homologous structures in different organisms, and what do they suggest in terms of evolution? What is an example?
Homologous structures are similar structures found in different organisms that indicate a common ancestry. They suggest that organisms share a common evolutionary history. An example is the forelimbs of vertebrates, such as the arms of humans, the wings of birds, and the flippers of whales.
What are vestigial structures, and what do they suggest in terms of evolution? What is an example?
Vestigial structures are anatomical features that have no apparent function in the organism but resemble functional structures in other species, suggesting a shared evolutionary past. An example is the human appendix, which is a vestigial structure that was likely functional in our evolutionary ancestors but no longer serves a significant purpose in humans.
What is natural selection?
Natural selection is the mechanism of evolution whereby individuals with favorable traits that are better adapted to their environment are more likely to survive, reproduce, and pass on their genes to the next generation.
Natural selection could not occur without ________________ variation.
Genetic variation.
What is the only type of characteristic that natural selection can affect?
Inherited traits or genetic characteristics.
What phrase sums up natural selection?
Survival of the fittest
What is a real-life example of natural selection? Explain it.
One example is the evolution of antibiotic resistance in bacteria. When exposed to antibiotics, some bacteria may have genetic variations that make them resistant to the drugs. These resistant bacteria are more likely to survive and reproduce, leading to the proliferation of antibiotic-resistant strains over time.
What is an adaptation?
An adaptation is a heritable trait or characteristic that enhances the survival and reproduction of an organism in its environment. Adaptations result from the process of natural selection.
What does the theory of evolution state?
The theory of evolution states that all species on Earth share a common ancestry and have changed over time through processes such as natural selection, genetic variation, and mutation.
What is meiosis?
Meiosis is a type of cell division that occurs in sexually reproducing organisms to produce gametes (sex cells). It involves two rounds of division, resulting in the halving of the chromosome number and the creation of genetically diverse offspring.
How does meiosis contribute to genetic variation?
Meiosis contributes to genetic variation through several processes, including crossing over (exchange of genetic material between homologous chromosomes), independent assortment of chromosomes, and random fertilization. These processes create unique combinations of genes in offspring.
What is so worrisome about antibiotic resistance?
Antibiotic resistance is concerning because it reduces the effectiveness of antibiotics in treating bacterial infections. Over time, bacteria can develop mechanisms to survive and multiply in the presence of antibiotics, making infections more difficult to treat and increasing the risk of spreading drug-resistant strains.
What is stabilizing selection?
Stabilizing selection is a type of natural selection that favors average or intermediate phenotypes, leading to a reduction in phenotypic variation. It occurs when the environment remains relatively stable. The graph for stabilizing selection is a bell-shaped curve with a peak in the middle.
What is disruptive selection
Disruptive selection is a type of natural selection that favors extreme phenotypes at both ends of the phenotypic spectrum, leading to an increase in phenotypic variation. The graph for disruptive selection has two peaks at opposite ends.
What seems to explain how domesticated dogs first came about? What type of selection was it?
Domesticated dogs likely arose through artificial selection, where humans selectively bred individuals with desired traits, such as specific physical characteristics or behavioral traits. This selective breeding led to the diversification of dog breeds we see today.
In Africa, one of the predators of guppies is a pike-cichlid that appears to hunt for larger and brighter colors, essentially visual cues. How might they affect the evolution of guppies if they were both introduced in a new lake together?
If pike-cichlids and guppies were introduced in a new lake together, the pike-cichlids' predation pressure would likely lead to the evolution of guppies with smaller and duller coloration. Guppies that exhibit these traits would be better able to evade predation, increasing their chances of survival and reproduction.
What evidence helps support the theory of evolution? Provide at least 4 pieces of evidence that support your claim and provide a reasoning as to why the evidence supports the claim.
Fossil record: Fossils show the existence of organisms that lived in the past and provide evidence for the gradual changes and transitions in species over time.
Comparative anatomy: Homologous structures in different organisms suggest a common ancestry and support the idea of evolutionary relationships.
Molecular genetics: The similarities in DNA and genetic sequences among different species indicate shared ancestry and evolutionary relationships.
Biogeography: The distribution of species across different geographical regions supports the idea of speciation and adaptation to different environments over time.
Heredity
The passing on of traits from parents to offspring.
Genetics
The study of heredity and variation in organisms.
Genotype
The genetic makeup of an organism
Phenotype
The physical expression of traits in an organism.
Allele
Different forms of a gene that can occupy the same gene locus on a chromosome
Probability
The likelihood of an event occurring.
Dominant
An allele that is expressed when present in either the homozygous or heterozygous state.
Recessive
An allele that is expressed only when present in the homozygous state.
Homozygous
Having two identical alleles for a particular gene
Heterozygous
Having two different alleles for a particular gene.
Chromosome
Thread-like structures in cells that contain genetic information.
Mutation
A change in the DNA sequence of a gene.
Genes
Units of heredity made up of DNA that determine specific traits.
Gene technology
The use of genetic information and techniques for practical purposes
Codon
A sequence of three nucleotides in DNA or RNA that corresponds to a specific amino acid or serves as a start or stop signal.
What is the structure of DNA?
Double helix formed by two strands of nucleotides.
Where is DNA found
Found in the nucleus
Whats makes up DNA
Base pairing: Adenine pairs with thymine (A-T) and cytosine pairs with guanine (C-G).
Double helix: Two DNA strands held together by hydrogen bonds between the complementary base pairs.
Who receives credit for the discovery of the structure of DNA? Who ought to receive more credit?
Discovery of the structure of DNA: James Watson and Francis Crick are credited with the discovery of the double helix structure of DNA.
Rosalind Franklin
What nucleotide bases pair across from each other in DNA? in RNA? Which base is found in RNA, but not DNA?
DNA base pairing: Adenine (A) pairs with thymine (T), and cytosine (C) pairs with guanine (G).
RNA base pairing: Adenine (A) pairs with uracil (U), and cytosine (C) pairs with guanine (G).
Base found in RNA, but not DNA: Uracil (U).
What are the steps for gene expression?
Transcription: DNA is transcribed into mRNA in the nucleus.
mRNA processing: Introns (non-coding regions) are removed, and exons (coding regions) are spliced together.
mRNA export: Processed mRNA is transported out of the nucleus and into the cytoplasm.
Translation: mRNA is translated into a specific sequence of amino acids to form a protein.
What does the central dogma state?
The central dogma of molecular biology states that genetic information flows from DNA to RNA to protein, with DNA serving as the blueprint for protein synthesis.
What basically occurs in transcription?
During transcription, the DNA sequence is copied into mRNA. RNA polymerase binds to the DNA template strand and synthesizes a complementary mRNA strand using base pairing rules (A-U, C-G). This occurs in the nucleus
What basically occurs in translation
During translation, the mRNA sequence is decoded by ribosomes to synthesize a specific sequence of amino acids, forming a protein. Transfer RNA (tRNA) molecules carry amino acids to the ribosome, and the mRNA sequence is read in sets of three nucleotides called codons. This process occurs in the cytoplasm.
What is natural selection? It can only act on what aspect of an organism for it to occur? How does it tie into gene expression?
Natural selection is the process by which certain heritable traits become more or less common in a population over time, based on their impact on survival and reproductive success. It leads to the adaptation of populations to their environment.
Natural selection acts on the phenotype (physical traits and behaviors) of an organism, which is determined by gene expression.
Tie to gene expression: Natural selection favors individuals with phenotypic traits that increase their fitness (survival and reproduction). These traits are influenced by gene expression, as gene regulation controls the production of proteins and the development of phenotypic characteristics.
Why is it necessary for Natural Selection to occur
Natural selection is necessary for the evolution of species and the development of new traits and characteristics.
Other than sexual reproduction, where does genetic variation often come from? How can these lead to evolution? What are two organisms that rapidly evolve today and how do they?
Genetic variation: Genetic variation often arises from mutations, which are changes in the DNA sequence. Mutations introduce new genetic material into a population, leading to genetic diversity.
Evolution: Genetic variation is the raw material for evolution. It provides the diversity on which natural selection acts, allowing populations to adapt to changing environments over time.
Rapidly evolving organisms: Examples of organisms that rapidly evolve are bacteria and viruses. Bacteria can develop antibiotic resistance through mutations, allowing them to survive and reproduce in the presence of antibiotics. Viruses, such as the influenza virus, undergo rapid genetic changes through genetic reassortment or mutations, leading to new strains and the need for updated vaccines.
What is the purpose of meiosis? What basically occurs in the two divisions of meiosis? What are the final products of a cell that underwent meiosis?
Purpose of meiosis: Meiosis is a specialized cell division process that produces gametes (sex cells) with half the number of chromosomes as the parent cell. Its purpose is to generate genetic diversity and ensure the correct chromosome number in offspring.
Two divisions of meiosis: Meiosis consists of two divisions: meiosis I and meiosis II.
Meiosis I: Homologous chromosomes pair up and exchange genetic material through crossing over. They separate, resulting in two daughter cells with half the chromosome number but still consisting of sister chromatids.
Meiosis II: Sister chromatids separate, resulting in four daughter cells with a haploid number of chromosomes (half the original number).
Final products: The final products of meiosis are four non-identical haploid cells, each containing a unique combination of genetic material.
Do all the cells of an organism have the same DNA? If so, how do they have different cells? So, how can two people who look so different be twins? How can identical twins be different?
Same DNA in cells: Yes, all cells in an organism contain the same DNA sequence.
Different cells: Different cells have different functions and express different genes. They have distinct patterns of gene expression, which determine their specialized functions and characteristics.
Differences between twins: Twins can look different even if they are identical (monozygotic) twins. This is because gene expression can be influenced by various factors, including environmental factors and epigenetic modifications. These factors can lead to differences in the expression of genes and phenotypic variations between identical twins.
What is the difference between a dominant allele and a recessive one? Is the dominant allele the most common allele? How many alleles exist for most traits? What typically happens with the frequency of an allele in a population if its expression offers an advantage to the organism?
Dominant and recessive alleles: Dominant alleles are expressed in the phenotype when present in either one or both copies, while recessive alleles are only expressed when present in both copies. Dominant alleles mask the expression of recessive alleles.
Dominance and commonality: The dominant allele is not necessarily the most common allele in a population. The frequency of alleles can vary depending on the population and evolutionary factors.
Alleles for most traits: Most traits are controlled by multiple alleles, with more than two possible forms of the gene.
Advantageous alleles: If an allele offers a reproductive or survival advantage to an organism, it is more likely to increase in frequency within a population over time through natural selection.
Sensory neurons
Neurons that transmit sensory information from sensory receptors to the central nervous system.
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