This document provides a simplified diagram of the glycolysis and tricarboxylic acid (TCA) cycle pathways, showing their interconnection and major products. Glycolysis breaks down glucose to produce pyruvate, ATP and NADH. Pyruvate then feeds into the TCA cycle in the mitochondria to further oxidize acetyl-CoA, producing more ATP, NADH, FADH2 and feeding electrons into the electron transport chain. Overall, the complete oxidation of glucose via these pathways generates numerous ATP, NADH, FADH2 and other products to fuel cellular metabolism.
This document provides an overview of glycolysis and the tricarboxylic acid (TCA) cycle, including their compartmentation within cells. Glycolysis is the breakdown of glucose to pyruvate, occurring in the cytoplasm. The TCA cycle then occurs in the mitochondria, where pyruvate is oxidized and carbon dioxide is released, generating reduced cofactors like NADH and FADH2 that are used to generate ATP through oxidative phosphorylation. Compartmentation separates these metabolic pathways between the cytoplasm and mitochondria, with transport mechanisms moving intermediates between compartments.
This document provides information on topics related to metabolism, cell respiration, and photosynthesis. It includes essential ideas, understandings, applications and skills, guidance, and theory of knowledge questions for each topic. For metabolism, it describes metabolic pathways, enzymes, and inhibition. For cell respiration, it explains the pathways of glycolysis, Krebs cycle, electron transport chain, and chemiosmosis. For photosynthesis, it describes the light-dependent and light-independent reactions, electron transport, and Calvin cycle.
Photosynthesis is the process by which plants manufacture carbohydrates from carbon dioxide and water using energy from sunlight. Chlorophyll traps light energy and converts it into chemical energy to form sugars and oxygen. The word equation for photosynthesis is: 6CO2 + 6H2O → C6H12O6 + 6O2. A leaf has features like chloroplasts for photosynthesis, stomata and mesophyll cells for gas exchange, and vascular bundles for transport and support. Important plant nutrients include nitrate ions for protein synthesis and magnesium ions for chlorophyll synthesis.
This document contains a syllabus covering topics related to nutrition, including:
1. The chemical components of carbohydrates, fats, and proteins.
2. Definitions of nutrition, digestion, and the process by which plants produce carbohydrates through photosynthesis.
3. An overview of the structure and functions of the human digestive system, including the roles of teeth, the alimentary canal, and absorption of digested nutrients.
A work in progress - drafts to be updated and completed later. Practice with the the assessment statements from the Core component of the course that require diagrams.
This document provides a simplified diagram of the glycolysis and tricarboxylic acid (TCA) cycle pathways, showing their interconnection and major products. Glycolysis breaks down glucose to produce pyruvate, ATP and NADH. Pyruvate then feeds into the TCA cycle in the mitochondria to further oxidize acetyl-CoA, producing more ATP, NADH, FADH2 and feeding electrons into the electron transport chain. Overall, the complete oxidation of glucose via these pathways generates numerous ATP, NADH, FADH2 and other products to fuel cellular metabolism.
This document provides an overview of glycolysis and the tricarboxylic acid (TCA) cycle, including their compartmentation within cells. Glycolysis is the breakdown of glucose to pyruvate, occurring in the cytoplasm. The TCA cycle then occurs in the mitochondria, where pyruvate is oxidized and carbon dioxide is released, generating reduced cofactors like NADH and FADH2 that are used to generate ATP through oxidative phosphorylation. Compartmentation separates these metabolic pathways between the cytoplasm and mitochondria, with transport mechanisms moving intermediates between compartments.
This document provides information on topics related to metabolism, cell respiration, and photosynthesis. It includes essential ideas, understandings, applications and skills, guidance, and theory of knowledge questions for each topic. For metabolism, it describes metabolic pathways, enzymes, and inhibition. For cell respiration, it explains the pathways of glycolysis, Krebs cycle, electron transport chain, and chemiosmosis. For photosynthesis, it describes the light-dependent and light-independent reactions, electron transport, and Calvin cycle.
Photosynthesis is the process by which plants manufacture carbohydrates from carbon dioxide and water using energy from sunlight. Chlorophyll traps light energy and converts it into chemical energy to form sugars and oxygen. The word equation for photosynthesis is: 6CO2 + 6H2O → C6H12O6 + 6O2. A leaf has features like chloroplasts for photosynthesis, stomata and mesophyll cells for gas exchange, and vascular bundles for transport and support. Important plant nutrients include nitrate ions for protein synthesis and magnesium ions for chlorophyll synthesis.
This document contains a syllabus covering topics related to nutrition, including:
1. The chemical components of carbohydrates, fats, and proteins.
2. Definitions of nutrition, digestion, and the process by which plants produce carbohydrates through photosynthesis.
3. An overview of the structure and functions of the human digestive system, including the roles of teeth, the alimentary canal, and absorption of digested nutrients.
A work in progress - drafts to be updated and completed later. Practice with the the assessment statements from the Core component of the course that require diagrams.
The document summarizes several important industrial chemical processes:
1) The Haber process produces ammonia from nitrogen and hydrogen gases using high temperature, pressure, and an iron oxide catalyst.
2) The contact process produces sulfuric acid via three reactions, using catalysts and optimized conditions to maximize sulfur trioxide production.
3) Lime is produced by heating limestone to decompose it into calcium oxide and carbon dioxide, and calcium hydroxide is made by adding water to calcium oxide.
The document provides instructions for students to complete various activities about absorption in biology:
1. Students should complete an absorption model activity, a Visking tube experiment to test for starch and glucose, and potentially start problem solving.
2. The Visking tube experiment involves setting up a diagram of the experiment, explaining test results in terms of molecule size, and recording a table of results.
3. The small intestine efficiently absorbs small, soluble molecules through adaptations like a large surface area from finger-like villi, a thin single-cell wall for rapid absorption, and good blood supply to vessels that receive absorbed materials.
The document discusses nutrients and their sources. It explains that foods contain nutrients like carbohydrates, proteins, fats, vitamins, and minerals that the body needs to function properly. Different foods provide different amounts and types of nutrients. It also discusses fiber and how different foods provide fiber, protein, carbohydrates, fat, vitamins, minerals, and other nutrients that are essential for health. Portion size determines how much energy and nutrients people get from food.
This revision guide is designed to help students study for the chemistry part of the IGCSE Coordinated Science course. It contains all the material needed according to the syllabus, along with suggestions for additional online resources. The guide provides a starting point for revision but students should also use textbooks and the internet to supplement their study. While covering the entire syllabus, the guide only includes the minimum information and is not sufficient for students aiming for the highest grades, who should read more in-depth sources.
This document is the syllabus for the 2012/2013 Malaysian Higher School Certificate Examination (STPM) Biology subject. It outlines the aims, objectives, content, assessment scheme and specimen papers for the course. The syllabus is divided into three terms, covering the topics of Biological Molecules and Metabolism in the first term, Physiology in the second term, and Ecology and Genetics in the third term. It aims to enhance students' understanding of biology and prepare them for tertiary education or careers in related fields.
Cellular respiration involves the breakdown of glucose and other organic molecules to extract energy in the form of ATP. It occurs in three main stages: glycolysis, the Krebs cycle in the mitochondria, and oxidative phosphorylation along the electron transport chain. During aerobic respiration, glucose breakdown yields about 38 ATP molecules total. Without oxygen, anaerobic respiration produces less ATP but allows glycolysis to continue by converting pyruvate into other waste products like lactic acid.
The document discusses the structure and function of the cardiovascular system. It describes the heart as a four-chambered pump made of cardiac muscle that circulates blood through the body. Blood travels through the heart chambers and vessels, passing through the lungs to collect oxygen and release carbon dioxide. The document also outlines the composition of blood and its role in transporting materials throughout the body.
The document discusses the role of enzymes in digestion. It begins by naming the organs of the digestive system in order. It then explains that different enzymes are added at various stages of digestion to break down different components of food. Specifically, amylase breaks down carbohydrates into sugars, proteases break down proteins into amino acids, and lipase breaks down fats into glycerol and fatty acids. Enzymes are able to carry out these breakdown processes through chemical reactions in acidic or emulsified environments tailored to their functions.
The document discusses the human digestive system. It explains that digestion breaks down large food molecules into smaller molecules that can be absorbed. Enzymes play an important role in speeding up digestion at body temperature. It lists the source, substrate, products and optimal pH for amylase, protease and lipase. Diagrams of the digestive system and villi are included to show their structures and roles in digestion, absorption and transport of nutrients.
1. The document defines key terms related to energy flow in ecosystems, including producers, consumers, herbivores, carnivores, decomposers, food chains, food webs, trophic levels, and ecosystems.
2. It states that energy is lost at each trophic level as it passes from organism to organism, and that food chains usually have fewer than five trophic levels due to these energy losses.
3. The document also briefly discusses the carbon cycle and the effects of fossil fuel combustion and deforestation on atmospheric carbon dioxide and oxygen levels.
Enzymes are proteins that act as biological catalysts. Changes in temperature and pH affect enzyme activity - increasing or decreasing the rate of reactions. Experiments can investigate and explain how altering conditions like temperature and pH impacts an enzyme's ability to function as a catalyst.
This document outlines the syllabus statements for a course on human influences on ecosystems. It lists several topics to be covered, including the undesirable effects of deforestation, overuse of fertilizers, pollution, acid rain, and the need for conservation of species, habitats, water resources, and non-renewable materials. It also states that increases in greenhouse gases like carbon dioxide and methane are thought to cause global warming.
Ventilation is the process of moving air in and out of the lungs to supply oxygen and remove carbon dioxide. Gas exchange occurs in the alveoli where oxygen and carbon dioxide diffuse between the blood in capillaries and the air in the alveoli. Cell respiration uses oxygen and produces carbon dioxide as a waste product. A ventilation system with trachea, bronchi, bronchioles and alveoli is needed to maintain concentration gradients driving gas exchange. The diaphragm and intercostal muscles contract and relax to change lung volume and pressure, inhaling and exhaling air through the ventilation system.
The document discusses different types of energy and energy resources. It explains that fossil fuels like coal, oil, and natural gas were formed over millions of years from the remains of ancient plants and animals. While these fossil fuels are non-renewable, some energy sources like wind and solar are renewable as they can be replenished. The majority of energy used in the UK currently comes from non-renewable fossil fuels rather than renewable options.
Implications of variation adaptation and natural selectionMarcia Roe
The document summarizes the biological concept of species and how new species originate through evolutionary processes such as geographic isolation, ecological isolation, and behavioral isolation. It explains that populations become reproductively isolated when they become separated geographically or evolve differences in habitats, breeding times, courtship behaviors, or physical attributes that prevent interbreeding. Even if closely related species can produce hybrid offspring, post-reproductive barriers like reduced hybrid viability or fertility act to maintain them as distinct species. The document also discusses debates around whether speciation occurs gradually over long periods or in rapid bursts separated by stasis.
This document is from a KS3 Physics textbook. It provides information on electrical circuits, including introducing series and parallel circuits. Key points covered include:
- Series circuits have components connected in a single loop so the current is the same throughout. The voltage splits between components.
- Parallel circuits have multiple paths so the current can split and join at junctions. The voltage is the same across each part.
- Energy from batteries is transferred through electrical circuits and converted to other forms like light and heat in bulbs. The total energy transferred equals the chemical energy lost from the battery.
This document outlines the key concepts around cell structure and movement into and out of cells that students should understand. It includes identifying the structures of plant and animal cells under a microscope and relating those structures to their functions. It also defines diffusion and osmosis, and describes their importance in the movement of gases, solutes, water and how osmosis specifically impacts the uptake of water in plants.
7 l the solar system & beyond (boardworks)cartlidge
This document is a physics textbook section about the solar system and beyond. It contains information on topics like the rotation of the Earth and causes of day and night, seasons, the phases of the Moon, eclipses, and an overview of the planets in our solar system including their sizes, distances from the sun, temperatures, and other characteristics. Diagrams and activities are also included to help explain different concepts.
The document discusses different types of instruments used to measure temperature, volume, length, circumference, mass, and how to read them correctly. It explains that a clinical thermometer measures body temperature, a digital thermometer measures surrounding temperature, and a laboratory thermometer measures temperature in science experiments. It also describes how to use a string and ruler to measure the circumference of an object, and that mass can be measured using a lever balance, electronic balance, or weighing scale in grams or kilograms.
The nucleus controls the cell's activities and contains DNA in the form of chromatin. Within the nucleus are nucleoli which produce rRNA and help assemble ribosomes. The nuclear membrane contains pores that allow transport of molecules. Mitochondria contain folded inner membranes called cristae where aerobic respiration occurs to produce ATP. The Golgi apparatus packages proteins for secretion and produces carbohydrates and glycoproteins. Lysosomes contain digestive enzymes to break down worn out organelles. Centrioles help produce the spindle during cell division. The endoplasmic reticulum is involved in protein and lipid transport. Ribosomes contain rRNA and protein and are involved in protein synthesis. The cytoplasm contains organelles and transports materials. The cell membrane forms the boundary
Here are the answers to the questions:
1. In a prokaryotic cell, the genetic material is a single loop of DNA not enclosed in a nucleus.
2. In a eukaryotic cell, the genetic material (DNA) is enclosed within a nucleus.
3. See table below
Prefix Multiple Standard form
centi (cm) 1 cm = 0.01 m x 10-2
milli (mm) 1 mm = 0.001 m x 10-3
micro (μm) 1 μm = 0.000 001 m x 10-6
nano (nm) 1 nm = 0.000 000 001 m x 10-9
4
The document provides information on cell biology topics including cell structure, transport processes, and cell division. It contains:
1) Descriptions of plant and animal cell structures and comparisons between eukaryotic and prokaryotic cells.
2) Explanations of three transport processes - diffusion, osmosis, and active transport - and examples of each in cells and organisms.
3) An overview of cell division through mitosis and its role in growth and repair of cells.
The document summarizes several important industrial chemical processes:
1) The Haber process produces ammonia from nitrogen and hydrogen gases using high temperature, pressure, and an iron oxide catalyst.
2) The contact process produces sulfuric acid via three reactions, using catalysts and optimized conditions to maximize sulfur trioxide production.
3) Lime is produced by heating limestone to decompose it into calcium oxide and carbon dioxide, and calcium hydroxide is made by adding water to calcium oxide.
The document provides instructions for students to complete various activities about absorption in biology:
1. Students should complete an absorption model activity, a Visking tube experiment to test for starch and glucose, and potentially start problem solving.
2. The Visking tube experiment involves setting up a diagram of the experiment, explaining test results in terms of molecule size, and recording a table of results.
3. The small intestine efficiently absorbs small, soluble molecules through adaptations like a large surface area from finger-like villi, a thin single-cell wall for rapid absorption, and good blood supply to vessels that receive absorbed materials.
The document discusses nutrients and their sources. It explains that foods contain nutrients like carbohydrates, proteins, fats, vitamins, and minerals that the body needs to function properly. Different foods provide different amounts and types of nutrients. It also discusses fiber and how different foods provide fiber, protein, carbohydrates, fat, vitamins, minerals, and other nutrients that are essential for health. Portion size determines how much energy and nutrients people get from food.
This revision guide is designed to help students study for the chemistry part of the IGCSE Coordinated Science course. It contains all the material needed according to the syllabus, along with suggestions for additional online resources. The guide provides a starting point for revision but students should also use textbooks and the internet to supplement their study. While covering the entire syllabus, the guide only includes the minimum information and is not sufficient for students aiming for the highest grades, who should read more in-depth sources.
This document is the syllabus for the 2012/2013 Malaysian Higher School Certificate Examination (STPM) Biology subject. It outlines the aims, objectives, content, assessment scheme and specimen papers for the course. The syllabus is divided into three terms, covering the topics of Biological Molecules and Metabolism in the first term, Physiology in the second term, and Ecology and Genetics in the third term. It aims to enhance students' understanding of biology and prepare them for tertiary education or careers in related fields.
Cellular respiration involves the breakdown of glucose and other organic molecules to extract energy in the form of ATP. It occurs in three main stages: glycolysis, the Krebs cycle in the mitochondria, and oxidative phosphorylation along the electron transport chain. During aerobic respiration, glucose breakdown yields about 38 ATP molecules total. Without oxygen, anaerobic respiration produces less ATP but allows glycolysis to continue by converting pyruvate into other waste products like lactic acid.
The document discusses the structure and function of the cardiovascular system. It describes the heart as a four-chambered pump made of cardiac muscle that circulates blood through the body. Blood travels through the heart chambers and vessels, passing through the lungs to collect oxygen and release carbon dioxide. The document also outlines the composition of blood and its role in transporting materials throughout the body.
The document discusses the role of enzymes in digestion. It begins by naming the organs of the digestive system in order. It then explains that different enzymes are added at various stages of digestion to break down different components of food. Specifically, amylase breaks down carbohydrates into sugars, proteases break down proteins into amino acids, and lipase breaks down fats into glycerol and fatty acids. Enzymes are able to carry out these breakdown processes through chemical reactions in acidic or emulsified environments tailored to their functions.
The document discusses the human digestive system. It explains that digestion breaks down large food molecules into smaller molecules that can be absorbed. Enzymes play an important role in speeding up digestion at body temperature. It lists the source, substrate, products and optimal pH for amylase, protease and lipase. Diagrams of the digestive system and villi are included to show their structures and roles in digestion, absorption and transport of nutrients.
1. The document defines key terms related to energy flow in ecosystems, including producers, consumers, herbivores, carnivores, decomposers, food chains, food webs, trophic levels, and ecosystems.
2. It states that energy is lost at each trophic level as it passes from organism to organism, and that food chains usually have fewer than five trophic levels due to these energy losses.
3. The document also briefly discusses the carbon cycle and the effects of fossil fuel combustion and deforestation on atmospheric carbon dioxide and oxygen levels.
Enzymes are proteins that act as biological catalysts. Changes in temperature and pH affect enzyme activity - increasing or decreasing the rate of reactions. Experiments can investigate and explain how altering conditions like temperature and pH impacts an enzyme's ability to function as a catalyst.
This document outlines the syllabus statements for a course on human influences on ecosystems. It lists several topics to be covered, including the undesirable effects of deforestation, overuse of fertilizers, pollution, acid rain, and the need for conservation of species, habitats, water resources, and non-renewable materials. It also states that increases in greenhouse gases like carbon dioxide and methane are thought to cause global warming.
Ventilation is the process of moving air in and out of the lungs to supply oxygen and remove carbon dioxide. Gas exchange occurs in the alveoli where oxygen and carbon dioxide diffuse between the blood in capillaries and the air in the alveoli. Cell respiration uses oxygen and produces carbon dioxide as a waste product. A ventilation system with trachea, bronchi, bronchioles and alveoli is needed to maintain concentration gradients driving gas exchange. The diaphragm and intercostal muscles contract and relax to change lung volume and pressure, inhaling and exhaling air through the ventilation system.
The document discusses different types of energy and energy resources. It explains that fossil fuels like coal, oil, and natural gas were formed over millions of years from the remains of ancient plants and animals. While these fossil fuels are non-renewable, some energy sources like wind and solar are renewable as they can be replenished. The majority of energy used in the UK currently comes from non-renewable fossil fuels rather than renewable options.
Implications of variation adaptation and natural selectionMarcia Roe
The document summarizes the biological concept of species and how new species originate through evolutionary processes such as geographic isolation, ecological isolation, and behavioral isolation. It explains that populations become reproductively isolated when they become separated geographically or evolve differences in habitats, breeding times, courtship behaviors, or physical attributes that prevent interbreeding. Even if closely related species can produce hybrid offspring, post-reproductive barriers like reduced hybrid viability or fertility act to maintain them as distinct species. The document also discusses debates around whether speciation occurs gradually over long periods or in rapid bursts separated by stasis.
This document is from a KS3 Physics textbook. It provides information on electrical circuits, including introducing series and parallel circuits. Key points covered include:
- Series circuits have components connected in a single loop so the current is the same throughout. The voltage splits between components.
- Parallel circuits have multiple paths so the current can split and join at junctions. The voltage is the same across each part.
- Energy from batteries is transferred through electrical circuits and converted to other forms like light and heat in bulbs. The total energy transferred equals the chemical energy lost from the battery.
This document outlines the key concepts around cell structure and movement into and out of cells that students should understand. It includes identifying the structures of plant and animal cells under a microscope and relating those structures to their functions. It also defines diffusion and osmosis, and describes their importance in the movement of gases, solutes, water and how osmosis specifically impacts the uptake of water in plants.
7 l the solar system & beyond (boardworks)cartlidge
This document is a physics textbook section about the solar system and beyond. It contains information on topics like the rotation of the Earth and causes of day and night, seasons, the phases of the Moon, eclipses, and an overview of the planets in our solar system including their sizes, distances from the sun, temperatures, and other characteristics. Diagrams and activities are also included to help explain different concepts.
The document discusses different types of instruments used to measure temperature, volume, length, circumference, mass, and how to read them correctly. It explains that a clinical thermometer measures body temperature, a digital thermometer measures surrounding temperature, and a laboratory thermometer measures temperature in science experiments. It also describes how to use a string and ruler to measure the circumference of an object, and that mass can be measured using a lever balance, electronic balance, or weighing scale in grams or kilograms.
The nucleus controls the cell's activities and contains DNA in the form of chromatin. Within the nucleus are nucleoli which produce rRNA and help assemble ribosomes. The nuclear membrane contains pores that allow transport of molecules. Mitochondria contain folded inner membranes called cristae where aerobic respiration occurs to produce ATP. The Golgi apparatus packages proteins for secretion and produces carbohydrates and glycoproteins. Lysosomes contain digestive enzymes to break down worn out organelles. Centrioles help produce the spindle during cell division. The endoplasmic reticulum is involved in protein and lipid transport. Ribosomes contain rRNA and protein and are involved in protein synthesis. The cytoplasm contains organelles and transports materials. The cell membrane forms the boundary
Here are the answers to the questions:
1. In a prokaryotic cell, the genetic material is a single loop of DNA not enclosed in a nucleus.
2. In a eukaryotic cell, the genetic material (DNA) is enclosed within a nucleus.
3. See table below
Prefix Multiple Standard form
centi (cm) 1 cm = 0.01 m x 10-2
milli (mm) 1 mm = 0.001 m x 10-3
micro (μm) 1 μm = 0.000 001 m x 10-6
nano (nm) 1 nm = 0.000 000 001 m x 10-9
4
The document provides information on cell biology topics including cell structure, transport processes, and cell division. It contains:
1) Descriptions of plant and animal cell structures and comparisons between eukaryotic and prokaryotic cells.
2) Explanations of three transport processes - diffusion, osmosis, and active transport - and examples of each in cells and organisms.
3) An overview of cell division through mitosis and its role in growth and repair of cells.
Here are the key steps in cloning plants:
1) Plants can reproduce asexually through processes like producing runners or stolons, which will grow into clones that are genetically identical to the parent plant.
2) For example, a spider plant grows a rooting side branch called a stolon that will become a clone of the parent plant. A gardener may also take cuttings from a desirable plant to grow into clones.
3) The clones are genetically identical to the original parent plant and are called clones. The only variation between clones will come from environmental factors, not genetic differences. Asexual reproduction produces clones while sexual reproduction produces offspring with genetic variation.
Here are the answers to the questions about the structure and function of the human nervous system:
1. What is a stimulus? Any change in the surroundings.
2. What is a receptor? Cells that detect a change.
3. Name the two parts of the central nervous system. Brain and spinal cord.
4. What is an effector? A muscle or gland.
5. What does the CNS coordinate? The response of effectors.
6. Put these in the correct order: receptor, stimulus, response, coordinator, effector. Stimulus → receptor → coordinator → effector → response.
7. What is the role of the sensory neurone? To carry impulses from
The document discusses the human digestive system as an organ system where organs like the mouth, esophagus, stomach, and intestines work together to digest and absorb food using enzymes. It explains that digestion breaks down large insoluble molecules into smaller soluble ones that can be absorbed, and this process relies on enzymes released by organs like the salivary glands, pancreas, and stomach. Key enzymes and their roles in breaking down carbohydrates, proteins, and lipids are identified.
The document discusses different types of infectious diseases caused by pathogens such as viruses, bacteria, fungi and protists. It provides examples of viral diseases like measles and HIV, bacterial diseases including salmonella and gonorrhoea, and the fungal disease rose black spot and the protist disease malaria. The document explains how these diseases are transmitted and potential treatments or methods of control.
Photosynthesis is the process by which plants produce glucose from carbon dioxide and water using energy from sunlight. The rate of photosynthesis is affected by several factors including carbon dioxide concentration, temperature, and light intensity, with each factor limiting the rate once a certain threshold is reached. Experiments can measure the rate of photosynthesis by counting oxygen bubbles produced over time as light intensity or other factors are varied.
Here are the key advantages summarized:
- Sexual reproduction leads to variation in offspring through meiosis and mixing of genes from two parents. This variation provides a survival advantage if the environment changes.
- Asexual reproduction requires only one parent so it is more efficient in terms of time, energy and resources as no mate needs to be found. However, offspring are identical clones with no genetic variation.
- Both types of reproduction have advantages depending on circumstances. Sexual reproduction promotes variation for changing environments while asexual is more efficient for stable conditions.
The document discusses adaptations, interdependence and competition within ecological communities. It describes the different levels of ecological organization, including organisms, populations, communities, and ecosystems. Communities consist of many interacting populations that depend on each other through relationships like pollination, seed dispersal, and predator-prey interactions. Both biotic factors (living things) and abiotic factors (non-living things) influence communities. Organisms within communities compete for resources and adapt in ways that allow them to survive and reproduce under the prevailing environmental conditions. Competition and adaptations both help maintain a balanced community structure.
6.6 Hormones Homeo and Repro (Chris Paine)cartlidge
Thyroxin is a hormone produced by the thyroid gland that controls metabolism and affects growth and physiological processes. It regulates the metabolic rate and helps control body temperature. Most hormones affect multiple target tissues and have more than one effect. The document discusses thyroid hormones and their roles, as well as hormones involved in the menstrual cycle and their feedback mechanisms.
The document discusses neurons and synapses in the human brain. It begins by showing an image of a small segment of the human brain, with lines representing neurons and dots representing synapses. It notes that synapses are crucial for neural communication and thought. While the number of brain cells does not increase much after birth, the connections between neurons through synapses continue developing. The document then provides explanations of key concepts regarding neurons, synapses, and neural signaling. It explains how neurons transmit electrical signals, how synapses allow signals to be transmitted between neurons, and how signals propagate along axons through action potentials.
The document discusses gas exchange in the lungs. It explains that two processes maintain concentration gradients of oxygen and carbon dioxide between the alveoli and blood: 1) circulation brings deoxygenated blood to the alveoli, and 2) ventilation increases and decreases lung volume through muscle contractions, ensuring a supply of oxygenated air reaches the alveoli. The diaphragm and intercostal muscles contract during inhalation to inflate the lungs, allowing for gas exchange by diffusion across the alveoli.
The human body has structures and processes that resist the continuous threat of invasion by pathogens. These include leukocytes that ingest and destroy pathogens, as well as physical barriers like the skin and mucous membranes. The body also has mechanisms for blood clotting to prevent the entry of pathogens through cuts in the skin. Lymphocytes produce antibodies that provide specific immunity against particular pathogens. While antibiotics can treat bacterial infections by blocking bacterial processes, they are ineffective against viruses which lack metabolism and cannot be treated in the same way.
The blood system continuously transports substances to cells and collects waste through three main types of blood vessels. Arteries carry blood away from the heart to tissues and have muscle and elastic fibers to maintain blood pressure. Capillaries have thin walls that penetrate tissues and allow for exchange. Veins collect blood from tissues and return it to the heart, using valves to prevent backflow. William Harvey discovered the circulation of blood in the early 1600s, overturning earlier theories, and the heart acts as a pump initiated by the sinoatrial node to circulate blood continuously through this system.
6.1 Digestion and Absorption (Chris Paine)cartlidge
The small intestine has a structure that allows for both digestion and absorption of food. It has a folded inner wall and muscular outer layers that help move food along. The inner wall contains villi and microvilli that greatly increase the surface area for digestion and absorption. Enzymes in the small intestine digest macromolecules in food into smaller monomers. Absorption then occurs as these smaller molecules like glucose, amino acids, and fatty acids pass through the epithelial cells lining the villi into the bloodstream using various membrane transport processes. The liver plays an important role in processing absorbed glucose from the small intestine.
C ecology & conservation syllabus statementscartlidge
The document discusses various topics relating to ecology and conservation, including species and communities, ecosystems, impacts of humans, conservation of biodiversity, population ecology, and nitrogen and phosphorus cycles. It provides essential ideas, understandings, applications, and skills for each topic. For example, for species and communities the essential idea is that community structure emerges from ecosystem properties, and understandings include how limiting factors affect species distribution and the unique role each species plays.
The document discusses academic honesty and misconduct in the International Baccalaureate (IB) program. It defines key terms like plagiarism, collusion, and exam misconduct. It notes that over half of investigated cases involve plagiarism while a quarter involve collusion. The document warns students about the consequences of getting caught cheating, like being banned from future exams or failing their diploma. It emphasizes that students are responsible for knowing what constitutes academic dishonesty and how to properly cite sources to avoid plagiarism.
This document provides information about CAS (Creativity, Activity, Service) which is an important component of the International Baccalaureate Diploma Programme. It explains that CAS involves learning through experience, personal development, and making a difference to others. Students must be involved in a variety of CAS experiences over 18 months including activities in creativity, activity, and service, as well as a CAS project and ongoing reflection. The document outlines examples of acceptable CAS experiences and provides guidance on documenting CAS in a portfolio using the learning outcomes framework.
There are three main types of muscle tissue - skeletal, smooth, and cardiac. Muscle fibers are multinucleated cells formed from the fusion of individual embryonic muscle cells. Within each fiber are many parallel myofibrils composed of repeating sarcomere units. A sarcomere contains overlapping actin and myosin filaments. When an action potential reaches the neuromuscular junction, acetylcholine is released causing calcium ions to enter the fiber and allow the myosin heads to bind to actin, pulling the filaments together and contracting the muscle fiber. ATP provides energy to break the binding and reset the muscle for the next contraction.
There are three main types of muscle tissue - skeletal, smooth, and cardiac. Muscle fibers are multinucleate cells formed from the fusion of individual embryonic muscle cells. Within each fiber are many parallel myofibrils composed of repeating sarcomere units. A sarcomere contains overlapping actin and myosin filaments. When an action potential reaches the neuromuscular junction, acetylcholine is released causing calcium ions to enter the fiber and allow the myosin heads to bind to actin, pulling the filaments together and contracting the muscle fiber. ATP provides energy to break the binding and reset the filaments for the next contraction.