This document provides an overview of stem cells and their applications. It discusses that stem cells can divide many times and differentiate into other cell types, making them useful for growing tissues and replacing damaged cells. The document notes examples of stem cell treatments for eye diseases like Stargardt's disease and cancers like leukemia. For leukemia treatment, a patient's stem cells are collected, the patient undergoes chemotherapy to destroy cancerous cells, then their stem cells are returned to regrow the blood and immune system. The document also discusses ethical issues around sourcing stem cells and their therapeutic use.
DP Bio Option C-2 Communities and EcosystemsR. Price
1) The document discusses ecosystems and communities, including topics like trophic levels in food chains, food webs, and the relationship between climate and ecosystem structure.
2) It explains that the percentage of ingested energy converted to biomass depends on the respiration rate of organisms. Higher respiration means less energy is available to convert to biomass.
3) Disturbances influence ecosystem structure and change over time. Early succession has high diversity and productivity while climax ecosystems are more stable and resistant to change.
The document summarizes the nitrogen and phosphorus cycles. It explains that nitrogen-fixing bacteria convert atmospheric nitrogen to ammonia and that rhizobium bacteria associate with plant roots in a mutualistic relationship. It also notes that denitrifying bacteria can reduce nitrates in the absence of oxygen. The phosphorus cycle has a much lower turnover rate than the nitrogen cycle and phosphate availability may limit agriculture in the future.
1. A gene is a length of DNA located on a chromosome that influences a specific characteristic like height or eye color and can be passed from parents to offspring.
2. Genes are arranged in groups on chromosomes, with each gene occupying a specific locus.
3. Alleles are alternative forms of the same gene that cause variation in traits, such as different eye colors, and individuals typically have two alleles for each gene.
This document discusses four types of membrane transport: simple diffusion, facilitated diffusion, osmosis, and active transport. Simple diffusion and facilitated diffusion move particles down concentration gradients without ATP. Osmosis involves the movement of water down its concentration gradient. Active transport moves substances against concentration gradients using ATP. The document also notes that vesicles are small sacs that move materials within cells and that endocytosis and exocytosis allow materials to enter and exit cells.
DP Biology Option C.1 Species and CommunitiesR. Price
The distribution of species is affected by limiting factors such as temperature, water availability, and soil characteristics. Each species has a range of tolerance for these factors, and is excluded from areas outside this range. Species distributions also depend on the availability of resources like food and breeding sites. Within a community, each species fills a unique ecological niche defined by its habitat and interactions. The competitive exclusion principle states that two species cannot coexist indefinitely if their niches are identical. Species interactions in a community include competition, predation, parasitism, mutualism and commensalism. Keystone species have a disproportionate effect on community structure through their role in the food web.
Carbon dioxide and water vapor are the most significant greenhouse gases, responsible for 50% and 25% of the greenhouse effect respectively. Other gases like methane and nitrous oxide have smaller impacts, together accounting for less than 10%. The impact of a gas depends on how strongly it absorbs infrared radiation and its concentration in the atmosphere. Rising levels of carbon dioxide and other greenhouse gases since the industrial revolution have caused increased warming of the Earth's surface and atmosphere by trapping more of the infrared radiation emitted by the Earth. Multiple independent scientific analyses of ice core and other data show that increases in atmospheric carbon dioxide correspond to increases in global temperature.
1. Autotrophs like plants convert carbon dioxide from the atmosphere into carbohydrates and other carbon compounds through photosynthesis. This reduces the carbon dioxide concentration in the air and water.
2. Carbon dioxide dissolves in water as dissolved gas and hydrogen carbonate ions, which aquatic plants and autotrophs absorb. Carbon dioxide also diffuses into autotrophs down its concentration gradient from the air or water.
3. Aerobic respiration in organisms produces carbon dioxide as a waste product, which diffuses back out of organisms and into the surrounding air or water environment.
Cell division and the cell cycle were discussed. The cell cycle consists of growth, DNA synthesis, and cell division phases. In eukaryotes, cell division involves mitosis and cytokinesis. Cancer occurs when the cell cycle is deregulated and cells divide uncontrollably.
Yeast, specifically Saccharomyces cerevisiae, is a unicellular fungus that can be used to model population growth. It reproduces asexually through budding and derives energy through anaerobic respiration of glucose which produces carbon dioxide and ethanol as byproducts. Yeast has many societal uses including in baking, brewing, genetics research, and bioremediation. The exponential growth phase occurs in ideal, unlimited environments but slows as the population reaches the carrying capacity of the environment, following a sigmoid growth curve shaped by birth, death, immigration and emigration rates. Limiting factors like nutrients and herbivory can induce bottom-up or top-down population control. Sampling is used to
Phospholipids form bilayers in water due to their amphipathic properties. Phospholipids have a hydrophilic phosphate head and hydrophobic hydrocarbon tail. When mixed with water, the heads are attracted to water while the tails are attracted to each other, forming a double phospholipid layer that is the basis of cell membranes. Membrane proteins come in many forms and have diverse functions, including hormone and enzyme binding, cell adhesion, transport, and communication. Cholesterol is also a component of animal cell membranes, positioned between phospholipids to add structure.
This document provides an overview of stem cells and their applications. It discusses that stem cells can divide many times and differentiate into other cell types, making them useful for growing tissues and replacing damaged cells. The document notes examples of stem cell treatments for eye diseases like Stargardt's disease and cancers like leukemia. For leukemia treatment, a patient's stem cells are collected, the patient undergoes chemotherapy to destroy cancerous cells, then their stem cells are returned to regrow the blood and immune system. The document also discusses ethical issues around sourcing stem cells and their therapeutic use.
DP Bio Option C-2 Communities and EcosystemsR. Price
1) The document discusses ecosystems and communities, including topics like trophic levels in food chains, food webs, and the relationship between climate and ecosystem structure.
2) It explains that the percentage of ingested energy converted to biomass depends on the respiration rate of organisms. Higher respiration means less energy is available to convert to biomass.
3) Disturbances influence ecosystem structure and change over time. Early succession has high diversity and productivity while climax ecosystems are more stable and resistant to change.
The document summarizes the nitrogen and phosphorus cycles. It explains that nitrogen-fixing bacteria convert atmospheric nitrogen to ammonia and that rhizobium bacteria associate with plant roots in a mutualistic relationship. It also notes that denitrifying bacteria can reduce nitrates in the absence of oxygen. The phosphorus cycle has a much lower turnover rate than the nitrogen cycle and phosphate availability may limit agriculture in the future.
1. A gene is a length of DNA located on a chromosome that influences a specific characteristic like height or eye color and can be passed from parents to offspring.
2. Genes are arranged in groups on chromosomes, with each gene occupying a specific locus.
3. Alleles are alternative forms of the same gene that cause variation in traits, such as different eye colors, and individuals typically have two alleles for each gene.
This document discusses four types of membrane transport: simple diffusion, facilitated diffusion, osmosis, and active transport. Simple diffusion and facilitated diffusion move particles down concentration gradients without ATP. Osmosis involves the movement of water down its concentration gradient. Active transport moves substances against concentration gradients using ATP. The document also notes that vesicles are small sacs that move materials within cells and that endocytosis and exocytosis allow materials to enter and exit cells.
DP Biology Option C.1 Species and CommunitiesR. Price
The distribution of species is affected by limiting factors such as temperature, water availability, and soil characteristics. Each species has a range of tolerance for these factors, and is excluded from areas outside this range. Species distributions also depend on the availability of resources like food and breeding sites. Within a community, each species fills a unique ecological niche defined by its habitat and interactions. The competitive exclusion principle states that two species cannot coexist indefinitely if their niches are identical. Species interactions in a community include competition, predation, parasitism, mutualism and commensalism. Keystone species have a disproportionate effect on community structure through their role in the food web.
Carbon dioxide and water vapor are the most significant greenhouse gases, responsible for 50% and 25% of the greenhouse effect respectively. Other gases like methane and nitrous oxide have smaller impacts, together accounting for less than 10%. The impact of a gas depends on how strongly it absorbs infrared radiation and its concentration in the atmosphere. Rising levels of carbon dioxide and other greenhouse gases since the industrial revolution have caused increased warming of the Earth's surface and atmosphere by trapping more of the infrared radiation emitted by the Earth. Multiple independent scientific analyses of ice core and other data show that increases in atmospheric carbon dioxide correspond to increases in global temperature.
1. Autotrophs like plants convert carbon dioxide from the atmosphere into carbohydrates and other carbon compounds through photosynthesis. This reduces the carbon dioxide concentration in the air and water.
2. Carbon dioxide dissolves in water as dissolved gas and hydrogen carbonate ions, which aquatic plants and autotrophs absorb. Carbon dioxide also diffuses into autotrophs down its concentration gradient from the air or water.
3. Aerobic respiration in organisms produces carbon dioxide as a waste product, which diffuses back out of organisms and into the surrounding air or water environment.
Cell division and the cell cycle were discussed. The cell cycle consists of growth, DNA synthesis, and cell division phases. In eukaryotes, cell division involves mitosis and cytokinesis. Cancer occurs when the cell cycle is deregulated and cells divide uncontrollably.
Yeast, specifically Saccharomyces cerevisiae, is a unicellular fungus that can be used to model population growth. It reproduces asexually through budding and derives energy through anaerobic respiration of glucose which produces carbon dioxide and ethanol as byproducts. Yeast has many societal uses including in baking, brewing, genetics research, and bioremediation. The exponential growth phase occurs in ideal, unlimited environments but slows as the population reaches the carrying capacity of the environment, following a sigmoid growth curve shaped by birth, death, immigration and emigration rates. Limiting factors like nutrients and herbivory can induce bottom-up or top-down population control. Sampling is used to
Phospholipids form bilayers in water due to their amphipathic properties. Phospholipids have a hydrophilic phosphate head and hydrophobic hydrocarbon tail. When mixed with water, the heads are attracted to water while the tails are attracted to each other, forming a double phospholipid layer that is the basis of cell membranes. Membrane proteins come in many forms and have diverse functions, including hormone and enzyme binding, cell adhesion, transport, and communication. Cholesterol is also a component of animal cell membranes, positioned between phospholipids to add structure.
1) Prokaryotes have a simple cell structure without compartments, containing a cell membrane, cell wall, nucleoid region containing DNA but no nucleus, and 70S ribosomes.
2) Eukaryotic cells have a compartmentalized structure, with organelles that each have specialized functions contained within the cell, including a nucleus that houses the DNA.
3) Prokaryotes reproduce asexually through binary fission, where the single circular chromosome replicates and a copy moves to each end of the cell before the cell divides.
Meiosis involves two cell divisions that halve the number of chromosomes in a cell from diploid to haploid. During meiosis, homologous chromosomes pair up and may exchange genetic material through crossing over, then separate so each cell receives one chromosome from each pair to promote genetic variation. The halving of chromosomes allows for fertilization to restore the diploid number and genetic mixing between parents.
1) Gregor Mendel discovered the principles of inheritance through experiments crossing pea plants which involved large numbers of replicates and quantitative analysis.
2) Gametes contain a single allele for each gene making them haploid, and fusion of gametes during fertilization creates diploid zygotes containing two alleles for each gene which may be the same or different.
3) Dominant alleles will mask the effects of recessive alleles, but some genetic traits are codominant where both alleles have an effect when present together. Many genetic diseases are caused by recessive alleles requiring two copies of the allele.
Este documento trata sobre la informática. Define la informática como la ciencia que estudia el tratamiento automático y racional de la información. Explica que la informática se aplica a campos como la comunicación, medicina, educación, oficina, transporte, comercio e industria y recreación. Además, describe los componentes del ordenador como el hardware, que es la parte física, y el software, que es la parte lógica e inmaterial que utiliza el hardware para realizar tareas inteligentes.
1) Gravity has been studied and explained by many scientists throughout history, from Aristotle believing heavy objects moved towards the center of the universe, to Galileo discovering objects fall at the same rate regardless of mass, to Newton formulating the law of universal gravitation, to Einstein realizing gravity is the warping of spacetime by mass.
2) Stars produce energy through nuclear fusion, but eventually run out of fuel and die, either peacefully shrinking into white dwarfs, or violently exploding in supernovae leaving behind neutron stars or black holes with infinite gravity.
3) The universe began in a hot, dense state known as the Big Bang and has been expanding ever since, with gravity attracting matter to form galaxies,