bluuebunny/crossref_metadata_2025 huggingface dataset:
Organometallic Compounds of Transition Metals
Authors: Bochmann Manfred
Published: September 2023

This chapter looks at the synthesis of lithium. It emphasizes that lithium alkyls are made by reacting alkyl halides with lithium metal. The reaction is facilitated by a solvent that can stabilize the lithium ion, such as diethyl ether. The chapter also demonstrates the synthesis of lithium alkyls by transmetallation, then outlines the structure of lithium alkyls. As strong bases, lithium alkyls are used extensively for the deprotonation of C–H bonds. The addition of chelating donor ligands such as TMEDA has proved beneficial and greatly increases reactivity. Next, the chapter examines the ortho-directing effect and stereo-differentiating lithium reagents. It also considers organometallic compounds of the heavier alkali metals — Na-Cs.
Messenger RNA localization
Authors: Elliott David , Ladomery Michael
Published: September 2023

This chapter is focused on the localization of mRNAs1-6, including the localization of microRNAs in neurons. It describes fluorescence in situ hybridization (FISH). Fluorescence uses in situ hybridization wherein a complementary antisense nucleic acid probe is labelled typically with a fluorescent probe. The chapter also highlights how FISH techniques have been greatly improved, to the extent that it is now possible to examine the localization of thousands of mRNAs. The chapter discusses the importance of mRNA localization, which is powerfully illustrated by a genome-wide analysis by Eric Lecuyer and colleagues of mRNA localization during Drosophila embryogenesis. It looks at the machinery of mRNA localization, including the role of the cytoskeleton, RNA zipcodes, and the influence of the nuclear history of a transcript on its localization.
Pre-mRNA splicing by the spliceosome
Authors: Elliott David , Ladomery Michael
Published: September 2023

This chapter focuses on an important development in eukaryotic RNA processing, which is pre-mRNA splicing catalysed by the spliceosome. It explains that spliceosomal splicing is needed as a large proportion of eukaryotic genes are split between segments called introns and exons. The chapter also points out that splicing occurs in the nucleus during transcription and both the introns and exons of split genes are transcribed within the nucleus into long pre-mRNAs. The chapter mentions the origin of the name exon, which derives from the fact that exon sequences are EXpressed, while introns are removed by splicing and so are not expressed in the mature mRNA. It considers the biology of splicing.
Nucleocytoplasmic traffic of messenger RNA
Authors: Elliott David , Ladomery Michael
Published: September 2023

This chapter focuses on the nuclear export of mRNAs, which are encoded by ~21 000 genes in humans. Each of which is transcribed by RNA polymerase II. It explains that eukaryotic genes are transcribed in the nucleus but mRNAs are translated in the cytoplasm, implying that most mRNAs need to be exported across the nuclear membrane into the cytoplasm in order to be translated. It also shows that passage from the nucleus to the cytoplasm is one directional for mRNAs, prokaryotes have no nuclear membrane, and transcription takes place alongside translation. The chapter also displays that mRNA is exported from the nucleus by a different mechanism to that used for the non-coding, although protein-coding genes are numerous. It talks about the nuclear export of mRNA that starts at the gene and ends in the cytoplasm.
Clinical enzymology and biomarkers
Authors: Collinson Paul , Lloyd Amy
Published: September 2023

This chapter addresses clinical enzymology and biomarkers. Enzyme assays for diagnosing diseases depend on an increase in the activity or amount of enzyme present when a particular tissue is affected by illness and leakage or release of the enzyme into the blood. Enzymes are examples of biomarkers, which are biological molecules whose concentrations alter when there is disease. Cardiac disease occurs when the blood vessels supplying the heart become blocked. The principal biomarkers of cardiac damage are the cardiac troponins. The combination of a change (appearance) of cardiac troponin in the blood, plus changes in the electrocardiogram (ECG) and clinical features, can be used to diagnose and classify acute heart disease into stable angina, unstable angina, and myocardial infarction (MI). Meanwhile, natriuretic peptides are biomarkers of cardiac failure and can be used to diagnose both acute and chronic heart failure.
Disorders of calcium, phosphate, and magnesium homeostasis
Authors: Ahmed Nessar
Published: September 2023

This chapter studies the distribution, function, and metabolic regulation of calcium, phosphate, and magnesium in health. It discusses the disorders which cause an alteration in their plasma concentrations, together with their clinical presentation and laboratory investigations and management. Disorders of calcium homeostasis present as either abnormally high plasma calcium or hypercalcaemia, or abnormally low plasma calcium or hypocalcaemia. Meanwhile, disorders of phosphate homeostasis cause hyperphosphataemia or hypophosphataemia. Finally, disorders of magnesium homeostasis can cause either hypermagnesaemia or hypomagnesaemia. Biochemical tests can be used to diagnose disorders of calcium, phosphate, and magnesium homeostasis, and to identify their causes. The chapter then considers the clinical value of bone markers in metabolic bone disease. The major metabolic diseases affecting the bone are osteoporosis, osteomalacia, and Paget's disease.
Adrenal disease
Authors: Honour John
Published: September 2023

This chapter evaluates the morphology, development, functions, and regulation of the adrenal glands, before looking at adrenal disorders. The adrenal glands have an outer cortical region and an inner medulla with different functions. The adrenal cortex produces aldosterone, cortisol, and dehydroepiandrosterone sulfate (DHEAS); the medulla produces adrenaline and noradrenaline. In the newborn infant, metabolites of DHEAS are also produced by the fetal adrenal gland and can interfere with some methods. The execution and interpretation of laboratory hormone tests need special consideration, particularly with regard to assay specificity, reference ranges for age, development, and in some cases body size. The chapter then considers immunoassays, steroid hormone assays, and the analysis of the profile of urinary steroids by gas chromatography with mass spectrometry. A number of disorders of the adrenal glands are due to genetic defects in enzymes or neoplasms. Once recognized, these disorders are treatable by surgery and/or hormone replacement therapy.
Specific protein markers
Authors: Maguire Gerald
Published: September 2023

This chapter addresses the various proteins in plasma and the value of measuring their concentrations in relation to disease investigation. Plasma contains many different proteins each with a different function. Their concentrations in health are fairly constant but change in disease because of excessive rates of loss or altered rates of synthesis. The acute phase reaction affects the concentrations of several proteins: some increase and some decrease. Measurements of a number of serum proteins such as albumin, α1-antitrypsin, haptoglobin, caeruloplasmin, transferrin, and C-reactive protein are of value in investigation of certain disease states. Low concentrations of serum antibodies can result from secondary or primary causes and lead to susceptibility to bacterial infections, while high serum concentrations of antibody can be polyclonal or monoclonal in nature. The chapter then looks at the biuret method and agarose or capillary zone electrophoresis for measuring the concentration of proteins in serum.
Chemical toxicology
Authors: Ayers Gwendolen
Published: September 2023

This chapter reviews chemical toxicology. It considers different types of poisons, their clinical and biochemical features, their laboratory investigation, and management. Toxicology is the scientific study of poisons and poisoning, and has applications in many areas, including the industrial, agricultural, veterinary, environmental, forensic, and medical fields. In clinical biochemistry, the term toxicology is used to refer to the identification and measurement of the concentrations of poisons or biomarkers of their effects, in body fluids, tissues, and sometimes other materials. To appreciate why toxicology investigations are performed and the way results are used, it is important to know how poisoning occurs, how a diagnosis of poisoning is made, and how poisoning is treated.
Pericyclic Reactions
Authors: Ian Fleming
Published: September 2023

Pericyclic Reactions starts with a chapter on the nature of pericyclic reactions and considers how important they are. The following chapter looks at cycloaddition reactions. The text thereafter examines the Woodward–Hoffmann rules and molecular orbitals. There follows a chapter on electrocyclic reactions. Towards the end, the book moves on to sigmatropic rearrangements before turning to group transfer reactions in the final chapter.
Overview, energy levels, and the electromagnetic spectrum
Authors: Duckett Simon , Gilbert Bruce , Cockett Martin
Published: September 2023

This chapter reviews different experimental strategies that determine the geometrical arrangement of atoms in space which make up a particular molecule. It explains the choice of techniques to use when dealing with crystalline, liquid, or gas phase samples. It also outlines the structural relationship between functional groups in an organic molecule and the arrangements of ligands around a metal centre in a transition metal complex, including the way in which a cardiovascular drug molecule might bind within the protein cavity in haemoglobin. The chapter looks at the methods that rely on the interaction of photons or electrons with the molecule of interest. It illustrates the use photons that exploit whichever regions of the electromagnetic spectrum are appropriate to.
Organic Chemistry
Authors: Okuyama Tadashi , Maskill Howard
Published: September 2023

Organic Chemistry
begins by looking at chemical bonding and molecules. The text moves on to molecular structure and the shape of organic molecules. Other topics covered include organic compounds, conjugation, pi-electron delocalization, aromaticity, acids and bases. Chapters also examine organic reactions, nucleophilic addition, stereochemistry, reactions of alcohols and addition reactions of alkenes and alkynes. There are also chapters on enolate anions, enolate ions, and reactions of nucleophiles with alkenes and aromatic compounds. The text next turns to polycyclic and heterocyclic aromatic compounds, rearrangement reactions, pericyclic reactions, and rearrangement reactions involving polar molecules and ions. Finally, the text discusses biomolecules, chemistry of biomolecules, and the structural determination of organic compounds.
Electrophilic Aromatic Substitution
Authors: Okuyama Tadashi , Maskill Howard
Published: September 2023

This chapter focuses on aromaticity - the parent member of a large class of so-called aromatic compounds. It shows that benzene is a conjugated unsaturated compound which has special stability attributed to aromaticity. However, an organic compound does not have to be either aromatic, or not, as a whole: molecules of many compounds, including natural products and biologically important compounds, contain aromatic and non-aromatic residues linked together. The chapter then displays the distinguishing feature of an aromatic compound: its cyclic system of delocalized ? electrons. It looks at electrophilic aromatic substitution and the main reactions of benzene: halogenation, nitration, sulfonation, and Friedel-Crafts alkylation and acylation. Next, the chapter analyzes the regioselectivity of electrophilic substitution directed by substituents and the reactivity of phenol and aniline. It also looks at the preparation of substituted benzenes.
Enolate Ions, their Equivalents, and Reactions
Authors: Okuyama Tadashi , Maskill Howard
Published: September 2023

This chapter examines how carbonyl compounds undergo another characteristic type of reaction at the carbon ? to the carbonyl group. A hydrogen on the ? carbon is weakly acidic so carbonyl compounds are relatively easily deprotonated by strong bases to give their conjugate bases, enolate ions, which have a delocalized electron system and two reaction sites. The chapter then elaborates on the acidity of a C-H ? to a carbonyl group and Keto-enol tautomerism. It further discusses the acid-base catalysis of enolization and the nucleophilicity of enols and enolates. Typically, an enolate ion is a reactive intermediate which participates in various reactions as a nucleophile with electrophiles including halogens, carbonyl compounds, and alkyl halides. The chapter then analyzes the ?-Halogenation and the haloform reaction. It discusses the reactions between enolates and carbonyl compounds. It also investigates how enols, enamines, and enol silyl ethers react.
Nucleophilic Addition to the Carbonyl Group in Aldehydes and Ketones
Authors: Okuyama Tadashi , Maskill Howard
Published: September 2023

This chapter discusses the polarity of the carbonyl bond and the catalysis of nucleophilic addition to carbonyl groups by acids and bases. It considers in detail the reactions of a functional group, and looks at nucleophilic additions to the carbonyl group of aldehydes and ketones. The chapter argues that these reactions provide clear examples of several fundamental principles of organic reaction mechanisms, and they also include some of the most useful reactions for organic synthesis. The carbonyl (>C=O) group is a functional group found in aldehydes and ketones as well as carboxylic acids and their derivatives, and is one of the most important in organic and biological chemistry. The chapter ends by explicating the acetal and dithioacetal formation as well as the Wittig reaction. It also investigates the formation of imines and enamines.
Organic Synthesis
Authors: Okuyama Tadashi , Maskill Howard
Published: September 2023

This chapter looks at the reactions used in organic synthesis. It defines organic synthesis as the directed preparation of a sought compound usually, but not invariably, with some structural complexity from simple, readily available compounds. The chapter also develops the concept of retrosynthesis further and examines how to identify routes for syntheses of target compounds by applying organic reactions. Organic synthesis is one of the ultimate goals of organic chemistry and provides limitless opportunities to challenge the scientific imagination. The chapter then proceeds to discuss the synthons and the corresponding reagents as well as the reaction selectivity. Finally, the chapter elaborates on linear and convergent strategies, and presents some examples of organic synthesis.
Environmental enrichment
Authors: Hosey Geoff , Melfi Vicky , Pankhurst Sheila
Published: September 2023

This chapter focuses on environmental enrichment. It begins by discussing the evolution of enrichment as a concept. It explains that behavioural enrichment aims to successfully stimulate desirable behaviours, increase activity, and provide an easy method for monitoring the health of zoo animals. The chapter highlights the aims and goals of enrichment such as generating behavioural change in target animals. It then lists the types of enrichment and their function: food-based enrichment, physical enrichment, sensory enrichment, social enrichment, and cognitive enrichment. Next, the chapter notes the process of evaluating enrichment. It highlights the challenges posed by novelty and habituation when assessing how long the enrichment is effective. Additionally, the chapter mentions the benefits of environmental enrichment such as promoting breeding and the interaction of an animal with its environment.
Research
Authors: Hosey Geoff , Melfi Vicky , Pankhurst Sheila
Published: September 2023

This chapter discusses zoo research. It highlights the significance of zoo research with reference to the discovery of political behaviours in chimpanzees. Moreover, the chapter notes the various ways that research is being carried out in zoos such as applied studies, field-based conservation, and operational researches. It also mentions the research conducted by zoo staff such as collaborations, routine data collection, and zoo records. The chapter then presents the methodological difficulties that affect zoo research and raises frequent questions asked amidst behavioural research. There is a lack of data independence in zoos especially in terms of time sampling, animals in the same enclosure, and activity budgets.
Further Mendelian Principles
Authors: Thomas Alison
Published: September 2023

This chapter investigates modified Mendelian inheritance patterns, which indicate various genetic interactions and influencing factors. Genes and their alleles are always inherited according to Mendelian principles, but the phenotypic expression of a trait does not always follow simple Mendelian patterns. Different phenotypic ratios occur among F2 progeny in Mendelian breeding experiments when alleles are incomplete or co-dominant, epistatic interactions occur between genes, and an allele is located on a sex chromosome or organelle chromosome. There may be more than two alleles possible at a given locus. The chapter then looks at multiple alleles, lethal alleles, sex-linked traits, extrachromosomal inheritance, epistasis, and pedigree analysis.
Gene Mutations
Authors: Thomas Alison
Published: September 2023

This chapter highlights gene mutations, which are heritable changes in the information encoded by a gene. Mutations create genetic variation and produce heritable changes in the genetic information. Generally, mutations have a detrimental effect. Mutations may be spontaneous or induced by mutagens in the environment. If mutations occur in somatic cells, they affect that individual only. If they occur in germ-line cells, they affect future generations. Mutations may be small scale, affecting a single gene, or on a larger scale affecting whole chromosomes. The chapter then looks at how cells have DNA repair mechanisms that can restore short sequences of damaged DNA to their original sequence.
Proteomic analysis
Authors: Unwin Richard
Published: September 2023

This chapter discusses the methods for analysing the proteome which refers to the total protein content of cells or tissues. It examines the weaknesses and strengths of these methods to guide readers in choosing an appropriate one that would answer a particular biological question. The chapter looks at the purpose of proteomics research and its application and explains the major steps of a variety of proteomics workflows. It explains gel-based proteomics, protein identification by tandem mass spectrometry, and post-translational modifications. The chapter also describes label-free protein quantification, stable isotope labelling by amino acids in culture, isobaric tags, and absolute protein quantification, among others, in tackling quantitative mass spectrometry.
Bioimaging: light and electron microscopy
Authors: Howell Gareth , Dent Kyle
Published: September 2023

This chapter discusses the use of light and electron microscopy techniques to image biological structures. Bioimaging enables the visualization of different biological processes such as protein transport, the development or effect of disease, and mutations on a cellular and subcellular scale, and provides structural information on cells, organelles, and individual macromolecular complexes. The chapter looks at the technologies commonly used in studying cells and protein structures such as confocal microscopy, deconvolution microscopy, transmission electron microscopy, and scanning electron microscopy. It describes the basic structure of different microscopes and gives an overview of how images are generated and visualized. Furthermore, the discussion covers the common applications of these microscope technologies in modern biological research. It also explores correlative light electron microscopy, a technique that combines fluorescence microscopy and transmission electron microscopy to produce high-resolution images that include localized fluorescence information specific to the protein of interest.
Methods of studying cells
Authors: Wang Qiuyu , Smith Chris , Davis Emma
Published: September 2023

This chapter looks at several methods that have been devised to culture, identify, and characterize cells and their components, which has resulted in a wealth of advances in cell biology. It discusses culturing prokaryotic and eukaryotic cells, which means growing them in artificial media in a controlled environment. It also describes flow cytometry or cell sorting as a technique for counting cells and distinguishing and isolating specific cell types in a population of several different kinds of cells. The chapter mentions microscopy, which is a technique that uses a microscope to examine objects that are too small to be seen easily with the naked eye. It focuses on cell fractionation which involves separating the cells or tissue into a number of separate fractions.
Mitochondria, hydrogenosomes, and mitosomes
Authors: Wang Qiuyu , Smith Chris , Davis Emma
Published: September 2023

This chapter outlines the functions of the matrix of mitochondria as the site of oxidations or decarboxylation of pyruvate, the production of heat in some thermogenic tissues, and the formation of iron-sulfphur proteins. It talks about the inner mitochondrial membrane (IMM), which is the site of the production of ATP by oxidative phosphorylation and for initiating apoptosis. It also details the evolution of mitochondria, which is thought to have occurred from primitive bacteria that were endosymbionts of early eukaryotic cells that occurred at least 2000 million years ago. The chapter describes hydrogenosomes as spherical-shaped organelles of approximately 1-2 ?m diameter which are able to produce molecular or dihydrogen. It examines mitosomes which are found in a number of unicellular eukaryotic species that occupy anaerobic environmental niches and resemble hydrogenosomes in appearance.
Cell death
Authors: Wang Qiuyu , Smith Chris , Davis Emma
Published: September 2023

This chapter states that cell numbers in multicellular organisms are tightly regulated by the control of mitosis by mitogens and growth factors that stimulate cell division and growth and the genetically programmed death of damaged, diseased, or superfluous cells. It defines apoptosis as a highly regulated, genetically programmed process that eliminates unwanted, dysfunctional, or diseased cells by allowing them to self-degrade and die. It also mentions necrosis or accidental cell death, which can be caused by a chemical or physical assault to the cell or tissue. The chapter considers apoptosis as a natural part of the biology of multicellular organisms as it is involved in growth and development, maintaining homeostatic cell numbers, and eliminating cells that are diseased or have been damaged beyond repair. It looks at ways the balance in favour of apoptosis is induced, such as through certain types of physical or physiological stresses or lapses in the receipt of survival or trophic factors from other cells that prevent apoptosis.
Gas Chromatography
Authors: Granger Robert M. , Yochum Hank M. , Granger Jill N. , Sienerth Karl D. , Granger Robert M. , Yochum Hank M. , Granger Jill N. , Sienerth Karl D.
Published: September 2023

This chapter deals with gas chromatography (GC), which has been devised as an analytical tool for analyzing vapour-based trace compounds. It focuses on important areas of comparison and important differences between GC and liquid chromatography (LC), noting both in fundamentals and in applications. It also details how the GC technique separates components in the gas phase, using pressurized gas cylinders to provide carrier gas and valves to control flow rates. The chapter cites modern areas of interest and research involving GC, which include chiral separations in the pharmaceutical industry, organochlorine compounds, and pesticides. It considers GC as a useful technique for any compound that is volatile within the thermally stable range of the column, which is usually in the 40°C to 400°C range.
Electrophoresis
Authors: Granger Robert M. , Yochum Hank M. , Granger Jill N. , Sienerth Karl D. , Granger Robert M. , Yochum Hank M. , Granger Jill N. , Sienerth Karl D.
Published: September 2023

This chapter discusses the analytical technique of electrophoresis involving a very simple instrument, or what could be described in its most basic form as an apparatus. It explains that electrophoresis is used to separate and identify macromolecular species based on the differential migration of charged molecules in an electric field. It also mentions capillary electrophoresis, a particular form of electrophoresis, that has developed into an instrumental technique that offers fast run times, excellent resolution, automation, and options for obtaining quantitative results. The chapter considers electrophoresis as a separation technique that can be used analytically to characterize the compositions of mixtures and preparatively to isolate components of mixtures that are of interest. It points out that electrophoresis is a one-phase system as it involves components that are in the same phase.
Statistical Data Analysis
Authors: Granger Robert M. , Yochum Hank M. , Granger Jill N. , Sienerth Karl D. , Granger Robert M. , Yochum Hank M. , Granger Jill N. , Sienerth Karl D.
Published: September 2023

This chapter promotes a fundamental limit to how well we can know and be confident of the answer when making instrumental measurements. It points out that a real measurement cannot have a single true value and that a statement of the uncertainty in the number must accompany a real measurement. It also emphasizes how a scientific measurement can be “correct”, represent the best estimate of the mean of a set of replicate measurements, and be accompanied by an estimate of the uncertainty in the mean. The chapter suggests the best practice of always including a statement that describes how errors are included in scientific reports. It outlines three broad categories of error: gross error, systematic error, and random error.
Why Study Herpetology?
Authors: Harvey Pough F. , Andrews Robin M. , Crump Martha L. , Savitzky Alan H. , Wells Kentwood D. , Brandley Matthew C.
Published: September 2023

This chapter provides an overview of herpetology. Studies of amphibians and reptiles have played key roles in biological specializations as diverse as developmental biology, behaviour, ecology, and medicine. Many of these contributions are the result of unique characteristics that make a certain species of amphibian or reptile suitable for a particular technique. Herpetological studies have also contributed to advances in molecular biology and medicine. Many people are familiar with the major groups of amphibians and reptiles—salamanders, frogs and toads, turtles, crocodylians, and lizards and snakes—from visits to zoos or from televised nature programmes. The chapter then looks at the diversity of amphibians and reptiles, as well as their shared characteristics, focusing on ectothermy and endothermy. It also considers amphibians and reptiles in the context of terrestrial ecosystems.
The Biogeography of Amphibians and Reptiles
Authors: Harvey Pough F. , Andrews Robin M. , Crump Martha L. , Savitzky Alan H. , Wells Kentwood D. , Brandley Matthew C.
Published: September 2023

This chapter focuses on the biogeography of amphibians and reptiles. Biogeography combines information about natural history, phylogeny, geology, and climate to interpret the past and present distributions of taxa. It describes patterns of occurrence to understand the forces that create and maintain them. Two mechanisms—dispersal and vicariance—are responsible for the geographic distribution of organisms. Organisms move via dispersal to their present locations, by walking, swimming, flying, drifting, or being transported by another organism (often humans). Vicariance occurs when a new barrier fragments what had been a continuous geographic distribution of organisms into two or more discontinuous distributions. The chapter then considers phylogeography and island biogeography.
Body Support and Locomotion
Authors: Harvey Pough F. , Andrews Robin M. , Crump Martha L. , Savitzky Alan H. , Wells Kentwood D. , Brandley Matthew C.
Published: September 2023

This chapter considers the diversity of locomotor modes among amphibians and reptiles from a functional perspective, emphasizing the mechanics of locomotion and examining the underlying similarities observed among diverse taxa that have converged on similar locomotor patterns. The 17,000-plus extant species of amphibians and reptiles occupy habitats ranging from the open oceans to the crowns of rainforest trees and the depths of desert soils. Such diverse habitats require different modes of locomotion. Feet that gain purchase on a tree limb are very different from those required to propel their owner through a pond. Furthermore, several alternative solutions to the same locomotor challenge may exist, depending on the evolutionary starting points of the lineages involved. The chapter considers lever systems, terrestrial locomotion with limbs, jumping, terrestrial limbless locomotion, aquatic locomotion, burrowing, climbing, and aerial locomotion.
Feeding
Authors: Harvey Pough F. , Andrews Robin M. , Crump Martha L. , Savitzky Alan H. , Wells Kentwood D. , Brandley Matthew C.
Published: September 2023

This chapter demonstrates that amphibians and reptiles exhibit an extraordinary diversity of feeding modes, mirroring their range of habitats and the wide variety of foods consumed in water or on land. Most species are carnivorous and prey capture is enhanced in several groups by the use of a projectile tongue, which is fired from the mouth to ensnare the prey. Other species engulf prey with mobile cranial bones organized into complex linkages and controlled by a remarkable array of muscles. Venom-delivering systems have evolved independently in several lineages of snakes and lizards, apparently based on a shared genomic heritage, and the specializations associated with venom delivery can be spectacular. The chapter takes a functional perspective and groups organisms that exhibit similar feeding modes together. This organization requires the simultaneous consideration of independently evolved lineages, which emphasizes the pattern in which different evolutionary lines converge on similar solutions to shared functional problems.
Diets, Foraging, and Interactions with Parasites and Predators
Authors: Harvey Pough F. , Andrews Robin M. , Crump Martha L. , Savitzky Alan H. , Wells Kentwood D. , Brandley Matthew C.
Published: September 2023

This chapter begins by describing broad patterns of diet and the foraging behavior behaviour of amphibians and reptiles. These patterns are associated with morphological, physiological, and behavioral behavioural characters that facilitate location, identification, capture, ingestion, and digestion of food items. The chapter then considers amphibians and reptiles as food resources for other animals, including parasites. Because parasites are so small compared with their hosts, they are usually difficult or impossible to avoid. The response to parasitism is thus largely physiological, and defensive mechanisms involve the host's immune system. In contrast, predators can often be avoided or deterred, and amphibians and reptiles have evolved a range of overt defensive mechanisms. Finally, the chapter discusses an example of coevolution between a snake and its prey.
Populations and Species Assemblages
Authors: Harvey Pough F. , Andrews Robin M. , Crump Martha L. , Savitzky Alan H. , Wells Kentwood D. , Brandley Matthew C.
Published: September 2023

This chapter focuses on the aggregate properties of populations and species assemblages. It starts by discussing the demographic attributes of populations. Demography is the study of statistical properties of populations, including population size (i.e., the number of individuals), birth and death rates, age structure, and population growth rate. The chapter then looks at multispecies assemblages, which have their own aggregate properties, including species richness (the number of species in an assemblage, which is a common meaning of the term 'biodiversity') and the relative abundance of individuals of each species. Finally, it enlarges the geographic and taxonomic scales and discusses elevational and latitudinal gradients in species richness.
Conservation and the Future of Amphibians and Reptiles
Authors: Harvey Pough F. , Andrews Robin M. , Crump Martha L. , Savitzky Alan H. , Wells Kentwood D. , Brandley Matthew C.
Published: September 2023

This chapter assesses the conservation and the future of amphibians and reptiles. Amphibian declines are occurring at a rate estimated to be 200 times that of historical extinction levels; the extent of decline varies from region to region and within and among species. Reptiles may be in even greater danger of extinction than amphibians are, but we do not know much about the population status of many species. Although extinction is a natural phenomenon, most current extinctions result from human activities. The single most important impact of humans on amphibians and reptiles is habitat modification and destruction. The most successful conservation programs programmes identify and address the reason a species is endangered and at the same time provide benefits to local people. As such, the most important conservation action humans can take for amphibians and reptiles is to protect habitat.
The Evolution of Plant Diversity
Authors: Judd Walter S. , Campbell Christopher S. , Kellogg Elizabeth A. , Stevens Peter F. , Donoghue Michael J.
Published: September 2023

This chapter describes natural variation among individuals as an essential ingredient of evolution, elaborating how this variation arises and is distributed geographically. The chapter examines processes that create discrete units of variation that are of central interest to systematists, especially those that result in the formation of species. It also analyses mating between individuals of different plant species, blurring the boundary between species. This has little effect on morphological variation within a species. The chapter furthermore discusses interspecific gene flow. This plays a dual role in speciation, which includes reducing diversity by merging species. It highlights speciation when coupled with polyploidy, an important source of genetic variation within plant species.
Phylogenetic Relationships of Angiosperms
Authors: Judd Walter S. , Campbell Christopher S. , Kellogg Elizabeth A. , Stevens Peter F. , Donoghue Michael J.
Published: September 2023

This chapter concentrates on angiosperms or flowering plants, which are considered the dominant land plants and sister to a group that includes all other extant seed plants. Angiosperms have a long fossil record going back to the earliest Cretaceous period, and they possibly originated during the Jurassic period more than 140 million years ago. The chapter covers the two great groups of angiosperm species: monocots and eudicots. Monocots are plants with a single cotyledon and pollen grains that monosulcate, while eudicots are plants with two cotyledons and pollen grains that predominantly tricolpate. The chapter reviews data from DNA sequences and morphology that show that the monocot and eudicot clades are derived from members of a morphologically disparate, paraphyletic group of families.
A Changing Global Food System
Authors: Davies H. Maelor , Gepts Paul
Published: September 2023

This chapter examines the changes that have occurred in farming over the past 10,000 years and which continue today. Agriculture and food play an important role in the economic systems of all countries and regions. Indeed, crop and animal domestication — integral to the practices of farming — were essential for the development of human civilizations. Agricultural systems in different regions of the world differ in their productivity, and in the modern world, scientific and technological discoveries are responsible for many of those differences. Whereas modern science-driven agriculture is highly productive, especially in developed countries, a billion smallholder farmers in developing countries are confined to small farms where productivity is low and where they produce just enough food to supply themselves with the bare essentials of life.
Growth and Development
Authors: Chrispeels Maarten J.
Published: September 2023

This chapter details the structure and function of plant cells and organs and how an entire plant develops from a single fertilized egg cell. There is considerable emphasis on seed development, because most of the foods we eat are, at their core, made from the seeds of rice, wheat, and corn, as well as the seeds of legumes such as soybeans, peas, and beans. The chapter differentiates between shoot apical meristem (SAM) and root apical meristem (RAM). SAM is responsible for forming leaf and stem tissues, while RAM contains stem cells for the different root tissues and for the root cap, a small thimble-shaped mass of cells that protects the RAM as the root pushes through soil. The chapter also discusses the practice of raising plants from single cells in culture and the importance of this technique for micropropagation and genetic engineering.
The Rise of Conservation Biology
Authors: Cardinale Bradley J. , Primack Richard B. , Murdoch James D.
Published: September 2023

This chapter discusses the rise of conservation biology. Conservation biology is an interdisciplinary field that brings together experts from the natural sciences, social sciences, humanities, and economics as well as practices from natural resource management for a common purpose: to protect Earth's biodiversity. The field has three primary goals: to investigate and describe the full variety of life on the planet; to evaluate and predict the effects of human activities on biodiversity; and to develop practical solutions to protect and manage biodiversity sustainably. Since emerging as a distinct field in the mid-1980s, conservation biology has grown dramatically. The chapter traces the origins of conservation before looking at contemporary conservation biology and structured decision-making.
The Many Values of Biodiversity
Authors: Cardinale Bradley J. , Primack Richard B. , Murdoch James D.
Published: September 2023

This chapter evaluates how human values and ethics influence information and decision-making in conservation. Values are based on an individual's judgment about the relative worth, merit, usefulness, or importance of a thing or action. Meanwhile, ethics are a systematic way of organizing individual values into a set of principles that guide human conduct and behaviour. It is important to recognize that all decisions about biological conservation are, at their core, based on individual value systems, which are themselves heavily influenced by personal ethical views about the natural world. The chapter looks at three major value systems—intrinsic, relational, and instrumental—that are commonly used to justify the conservation of nature and its biodiversity. It then discusses three common ethical worldviews—anthropocentrism, biocentrism, and ecocentrism—that influence how people see their relationship with nature and its biota, which in turn influences how and why they value biodiversity in their lives.
Habitat Loss, Fragmentation, and Degradation
Authors: Cardinale Bradley J. , Primack Richard B. , Murdoch James D.
Published: September 2023

This chapter describes habitat loss, fragmentation, and degradation. Habitat loss poses the greatest threat to the variety of life on this planet today. It refers to complete elimination of habitats, along with their biological communities and ecological functions. Habitat loss usually results from the conversion of natural or semi-natural habitat into human-dominated habitat. Ultimately, it has been identified as the leading cause of population decay for most wildlife, and it is responsible for nearly 50 percent of all threatened mammal, bird, and amphibian species on the International Union for Conservation of Nature (IUCN) Red List of Threatened Species. Meanwhile, habitat fragmentation refers to the process by which larger, continuous habitats become subdivided into a greater number of smaller patches. Finally, habitat degradation refers to a suite of human activities that make the remaining habitat patches in a landscape less conducive to life, in turn eroding biodiversity.
Invasive Alien Species
Authors: Cardinale Bradley J. , Primack Richard B. , Murdoch James D.
Published: September 2023

This chapter studies the causes and consequences of invasive alien species (IAS), as well as the methods to manage and mitigate their impacts. A native species (or indigenous species) is one that occurs within its natural range (past or present) and that does so in the absence of dispersal that is assisted, either directly or indirectly, by humans. In contrast, an alien species (also called exotic, foreign, introduced, nonindigenous, or non-native species) is one that occurs outside of its natural range (past or present) and beyond its natural dispersal abilities, assisted in some way by human activities. Alien species are distinguished from IAS based on their impact. The spread of IAS has become a global problem involving nearly every major group of species. The chapter then looks at the impacts of IAS on biodiversity, ecosystems, and economies, including their potential positive values.
Landscape-Scale Conservation
Authors: Cardinale Bradley J. , Primack Richard B. , Murdoch James D.
Published: September 2023

This chapter evaluates landscape-scale conservation. A landscape is a large geographic region that span multiple biological communities and ecosystems and that includes different habitat types. Because of habitat loss, fragmentation, and degradation, landscapes throughout the world are increasingly patchy spatial mosaics where natural habitats have been lost and converted to human uses, others have been heavily degraded, and the natural habitats that remain are small, fragmented, and disconnected from one another. Landscapes like these are referred to as landscape mosaics or patch mosaics. The chapter discusses the creation of networks of protected areas in a landscape mosaic; the incorporation of unprotected habitats into the landscape network in order to complement the goals of conservation; and the measurement, monitoring, and management of the landscape to achieve broad-scale conservation goals.
Conservation and Sustainable Development
Authors: Cardinale Bradley J. , Primack Richard B. , Murdoch James D.
Published: September 2023

This chapter assesses sustainable development. By the early 1970s, environmental concerns had become an important international issue that launched a new era focused on growth that was more sustainable. A new paradigm of sustainable development subsequently emerged and gained popularity in the 1980s, contributing to the founding of the field of conservation biology. According to the Brundtland Commission report to the United Nations, ‘sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs’. The chapter then looks at the challenges that sustainable development presents for conservation. It describes some of the major initiatives and conventions that guide sustainable development at the international level, the sources of funding for sustainable development activities, and some examples of sustainable development projects. Finally, the chapter considers areas that could improve the success of sustainable development in the future.
Plant and Cell Architecture
Authors: Taiz Lincoln , Zeiger Eduardo , Møller Ian Max , Murphy Angus
Published: September 2023

This chapter provides an overview of the basic anatomy and cell biology of plants, from the macroscopic structure of organs and tissues to the microscopic ultrastructure of cellular organelles. It begins by looking at the unifying principles of plant life processes. All plants convert solar energy to chemical energy. They use growth instead of motility to obtain resources, and have vascular systems, rigid structures, and mechanisms to avoid desiccation on land. Plants develop from embryos sustained and protected by tissues from the mother plant. The chapter then explains plant classification and plant life cycles, before presenting an overview of plant structure. It describes plant cell types, plant cell organelles, the nucleus, the endomembrane system, independently dividing semiautonomous organelles, the plant cytoskeleton, and cell cycle regulation.
Water Balance of Plants
Authors: Taiz Lincoln , Zeiger Eduardo , Møller Ian Max , Murphy Angus
Published: September 2023

This chapter examines the mechanisms and driving forces operating on water transport within the plant and between the plant and its environment. To meet the contradictory demands of maximizing carbon dioxide uptake while limiting water loss, plants have evolved to control water loss from leaves, and to replace the water lost to the atmosphere with water drawn from the soil. The chapter thus begins by focusing on water in the soil. It then considers how water moves from the soil into the roots and from the roots up through specialized transport cells to the leaves from which water is lost to the atmosphere. Finally, the chapter looks at the ways in which the leaf can control the loss of water, as well as the entry of CO2, by regulating the opening and closing of stomata, the small openings through which the major water loss occurs.
Respiration and Lipid Metabolism
Authors: Taiz Lincoln , Zeiger Eduardo , Møller Ian Max , Murphy Angus
Published: September 2023

This chapter reviews plant respiration and lipid metabolism. Aerobic respiration is the biological process by which reduced organic compounds are oxidized in a controlled manner. The chapter looks at respiration in its metabolic context, emphasizing the interconnections among the processes involved and the special features that are peculiar to plants. It also relates respiration to recent developments in the understanding of the biochemistry and molecular biology of plant mitochondria and respiratory fluxes in intact plant tissues. The chapter then describes the pathways of lipid biosynthesis that lead to the accumulation of fats and oils, which many plant species use for energy and carbon storage. Finally, it discusses the catabolic pathways involved in the breakdown of lipids and the conversion of their degradation products into sugars that occurs during the germination of fat-storing seeds.
Flowering and Fruit Development
Authors: Taiz Lincoln , Zeiger Eduardo , Møller Ian Max , Murphy Angus
Published: September 2023

This chapter assesses flowering and fruit development. Flowering at the correct time of the year is crucial for the reproductive fitness of the plant. The transition to flowering involves major changes in the pattern of morphogenesis and cell differentiation at the shoot apical meristem (SAM). Ultimately, this process leads to the production of the floral organs: sepals, petals, stamens, and carpels. The process by which the SAM becomes committed to forming flowers is termed floral evocation. Photoperiodism and vernalization are two of the most important mechanisms underlying seasonal responses. Photoperiodism is a response to the length of day or night, while vernalization is the promotion of flowering by prolonged cold temperature. Other signals, such as light quality, ambient temperature, and abiotic stress, are also important external cues for plant development. The chapter also considers pollen development, pollination, and double fertilization in flowering plants.