Chapter 4—Ecosystems and Communities

 

 

Chapter 5—How Populations Grow

 

Chapter 6—Humans in the Biosphere

·         Among the human activities that have transformed the biosphere are hunting and gathering, agriculture, industry, and urban development

·         These groups supplement their diet with the meat of wild animals through subsistence hunting

·         Agriculture-farming

·         In a global effort to increase food production, governments and scientists introduced new, intensive farming practices that greatly increased yields of rice, wheat, and other crops known as the green revolution

·         Another strategy was to use a method called monoculture

·         Regardless of whether they are held in common, environmental resources can be classified into two types: renewable and nonrenewable

·         Renewable resources can regenerate and are therefore replaceable

·         A nonrenewable resource is one that cannot be replenished by natural resources

·         Sustainable use is a way of using natural resources at a rate that does not deplete them

·         Human activities affect the supply and the quality of renewable resources, including resources such as land, forests, ocean resources, air, and water

·         Soil erosion-the wearing away of surface soil by water and wind

·         In certain parts of the world with dry climates, a combination of farming, overgrazing, and drought has turned once productive areas into deserts-a process called desertification

·         Loss of forests-deforestation

·         Aquaculture-the farming of aquatic organisms

·         Smog-a mixture of chemicals that occurs as a gray-brown haze in the atmosphere

·         A pollutant is a harmful material that can enter the biosphere through the land, air, or water

·         Strong acids can drift for miles before they fall as acid rain

·         Another word for variety is diversity, therefore, biological diversity, or biodiversity, is the sum total of the genetically based  variety of all organisms in the biosphere

·         Ecosystem diversity includes the variety of habitants, communities, and ecological processes in the living world

·         Species diversity refers to the number of different species in the biosphere

·         Genetic diversity refers to the sum total of all the different forms of genetic information carried by all organisms living on the Earth today

·         Biodiversity is one of the Earth’s greatest natural resources. Species of many kinds have provided us with foods, industrial products, and medicines—including painkillers, antibiotics, heart drugs, antidepressants, and anticancer drugs

·         Human activity can reduce biodiversity by altering habitats, hunting species to extinction, introducing toxic compounds into food webs, and introducing foreign species to new environments

·         Extinction occurs when a species disappears from all or part of its range

·         A species whose population size is declining in a way that places it in danger of extinction is called an endangered species

·         Development often splits ecosystems into pieces, a process called habitat fragmentation

·         In biological magnification, concentrations of a harmful substance increase in organisms at a higher trophic level in a food chain or food web

·         Invasive species reproduce rapidly

·         Conservation is used to describe the wise management of natural resources, including the preservation of habitats and wildlife

·         Today, conservation efforts focus on protecting entire ecosystems as well as single species. Protecting an ecosystem will ensure that the natural habitats and the interactions of many different species are preserved at the same time

·         Many biologists are concerned about the biological effects of two types of global change: the thinning, or depletion, of the ozone layer and global warming

·         Between 20 and 50 kilometers above the Earth’s surface, the atmosphere contains a concentration of ozone gas—the ozone layer

·         The term used to describe this increase in the average temperature of the biosphere is global warming

Chapter 8- Photosynthesis

1.       H2O

2.       Carbon

3.       Light

4.       Chlorophyll

Chapter 9-Cellular Respiration

·         What problems does growth cause for cells?

o    The larger a cell becomes, the more demands the cell places on its DNA and the more trouble the cell has moving enough nutrient and wastes across the cell membrane

·         Cell division is a process by which a cell divides into 2 new daughter cells

·         Chromatids are one of two identical sister parts of a duplicated chromosome

·         Centromere is an area where the chromatids of a chromosome are attached

·         Interphase is the period of the cell cycle between cell divisions

·         What happens during the cell cycle?

o    A cell grows, prepares fro divisions, and divides to form 2 daughter cells each of which then begins the cycle again

·         How do biologist divide the events of mitosis?

o    They divide mitosis into 4 phases

1.       Prophase

2.       Metaphase

3.       Anaphase

4.       Telophase

·         Prophase is the 1st and longest stage of mitosis, during which the chromosomes become visible and the centrioles separate and take up positions on opposite sides of the nucleus

·         Centrioles are one of two tiny structures located in the cytoplasm of animal cells near the nuclear envelope

·         Spindles are fanlike microtubules structures that help separate the chromosomes during mitosis

·         Metaphase is the 2nd phase of mitosis, during which the chromosomes line up across the center of the cell

·         Anaphase is the 3rd phase of mitosis, during which the chromosome pairs separate and move towards opposite poles

·         Telophase is the 4th and final stage of mitosis, during which the chromosomes begin to disperse into a tangle of dense material

·         Cytokinesis is the division of the cytoplasm during cell division

·         Cyclin is one of a family of closely related proteins that regulate the cell cycle in eukaryotic cells

·         Cancer is a disorder in which some of the body’s own cells lose the ability to control growth   

·         Mutation is the change in a DNA sequence that affects genetic info 

·         What do gene mutations result from?

o    Results from changes in a single gene.  Chromosomal mutations involve changes in whole chromosomes

·         Point mutations are mutations that affect a single nucleotide, usually by substituting one nucleotide for another

·         Frame-shift mutations are mutations that shift the reading frame of the genetic message by inserting or deleting a nucleotide

Chapter 11- Introduction to Genetics

 

·         Sine alleles are neither dominant nor recessive, and many traits are controlled by multiple alleles or multiple genes

·         Cases in which one alleles is not completely dominant over another are called incomplete dominance

·         A similar situation is codominance, in which both alleles contribute to the phenotype of the organism

·         Many genes have more than two alleles and are therefore said to have multiple alleles

·         Traits controlled by two or more genes are said to be polygenic traits, which means “having many genes”

·         Two sets of chromosomes are homologous, meaning that each of the 4 chromosomes that came from the male parent has a corresponding chromosome from the female parent

·         A cell that contains both sets of homologous chromosomes is said to be diploid, meaning “two sets”

·         Gametes containing only one set of chromosomes and only a single set of genes is said to be haploid meaning “one set”

·         Meiosis is a process  of reduction division in which the number of chromosomes per cell is cut in half through the separation of homologous chromosomes in a diploid cell

·         In prophase of meiosis I, each chromosome pairs with its corresponding homologous chromosome to form a structure called a tetrad

·         As homologous chromosomes pair up and form tetrads in meiosis I, they may exchange portions of their chromatids in a process called crossing-over

·         Mitosis results in the production of two genetically identical diploid cells, whereas meiosis produces four genetically different haploid cells

·         It is chromosomes that assort independently, not individual genes

·         A gene map shows the relative locations of each known gene

 

Chapter 13—Changing the Living World (covered in Heredity Crash course and parts of activities)

 

·         By selective breeding, allowing only those animals with desired characteristics to produce the next generation, humans have produced the many different breeds

·         Humans use selective breeding to pass desired traits on to the next generation of organisms

·         Hybridization-crossing dissimilar individuals to bring together the best of both organisms

·         Interbreeding is the continued breeding of individuals with similar characteristics

·         Breeders can increase the genetic variation in a population by inducing mutations, which are the ultimate source of genetic variability

·         Polyploidy-they have many sets of chromosomes

·         Scientists use their knowledge of the structure of DNA and its chemical properties to study and change DNA molecules. Different techniques are used to extract DNA from cells, to cut DNA into smaller pieces, to identify the sequence of bases in a DNA molecule, and to make unlimited copies of DNA

·         Genetic engineering making changes in the DNA code of a living organism

·         Hundreds of restriction enzymes are known and each one cuts DNA at a specific sequence of nucleotides

·         In gel electrophoresis, a mixture of DNA fragments is placed at one end of a porous gel, and an electric voltage is applied to the gel

·         Some DNA molecules are known as recombinant DNA because they are produced by combining DNA from different sources

·         Like a photocopy machine stuck on “print,” a technique known as polymerase chain reaction (PCR) allows biologists to do exactly that

·         During transformation, a cell takes in DNA from outside the cell. This external DNA becomes a part of the cell’s DNA

·         Plasmids are found naturally in some bacteria and have been very useful for DNA transfer

·         The plasmid has a genetic marker—a gene that makes it possible to distinguish bacteria that carry the plasmid (and the foreign DNA) from those that don’t

·         If transformation is successful, the recombinant DNA is integrated into one of the chromosomes of the cell

·         The universal nature of genetic mechanisms makes it possible to construct organisms that are transgenic, meaning that they contain genes from other organisms

·         Genetic engineering has spurred the growth of biotechnology, a new industry that is changing the way we interact with the living world

·         A clone is a member of a population of genetically identical cells produced from a single cell

 

Chapter 14—The Human Genome

 

·         A picture of a chromosome arranged in pairs is known as a karyotype

·         Two of the 46 chromosomes are known as sex chromosomes, because they determine an individual’s sex

·         Females have two Xs and males an X and Y

·         The remaining 44 chromosomes are known as autosomal chromosomes, or autosomes

·         All egg cells carry a single X chromosome. However, half of all sperm cells carry an X chromosome and half carry a Y chromosome. This ensures that just about half of the zygotes will be 46XX and half will be 46XY

·         A pedigree chart, which shows the relationships within a family, can be used to help study how a trait is passed from one generation to the next

·         Some traits are polygenic meaning they are controlled by many genes

·         In both cystic fibrosis and sickle cell disease, a small change in the DNA of a single gene affects the structure of a protein, causing a serious genetic disorder

·         Genes located on the X or Y chromosome are sex-linked genes

·         Males have just one X chromosome. Thus, all X-linked alleles are expressed in males, even if they are recessive

·         The most common error in meiosis occurs when homologous chromosomes fail to separate, known as nondisjunction which means “not coming apart”

·         If nondisjunction  occurs, abnormal numbers of  chromosomes may find their way into gametes, and a disorder of chromosome numbers may result

·         Molecular biology has used this biological fact to add a powerful new tool called DNA fingerprinting to the identification of individuals

·         The Human Genome Project is an attempt to sequence all human DNA

·         In gene therapy, an absent or faulty gene is replaces by a normal, working gene

 

Chapter 15—Darwin’s Theory of Evolution

 

·         Evolution, or change over time, is the process by which modern organisms have descended from ancient organisms

·         A theory is a well-supported testable explanation of the phenomena that have occurred in the natural world

·         During his travels, Darwin made numerous observations and collected evidence that led him to propose a revolutionary hypothesis about the way life changes over time

·         Darwin collected the preserved remains of ancient organisms, called fossils

·         Darwin observed that the characteristics of many animals and plants varied noticeably among the different islands of the Galapagos

·         Hutton and Lyell helped scientists recognize that Earth is many millions of years old, and the processes that changed Earth in the past are the same processes that operate in the present

·         Lamarck proposed that by selective use or disuse of organs, organisms acquired or lost certain traits during their lifetime. These traits could then be passed on to their offspring. Over time, this process led to change in a species

·         Malthus reasoned that if the human population continued to grow unchecked, sooner or later there would be insufficient living space and food for everyone

·         Natural variation-differences among individuals of a species, is found in all types of organisms

·         Using artificial selection, breeders were able to produce a wide range of plants and animals that looked different from their ancestors

·         In artificial selection, nature provided the variation among different organisms, and the humans selected those variations they found useful

·         The struggle for existence means that members of each species compete regularly to obtain food, living space, and other necessities of life

·         Darwin called the ability of an individual to survive and reproduce in its specific environment fitness

·         An adaptation is any inherited characteristic that increases an organism’s chance of survival

·         Organisms that survive and reproduce successfully-survival of the fittest

·         Darwin referred to the survival of the fittest as natural selection

·         Over time, natural selection results in changes in the inherited characteristics of a population. These changes increase a species’ fitness in its environment

·         Each living species has descended, with changes, from another species over time is known as descent with modification

·         Common descent-all species—living or extinct—were derived from common ancestors

·         Darwin argues that living things have been evolving on Earth for millions of years. Evidence for this process could be found in the fossil record, the geographical distribution of living species, homologous structures of living organisms, and similarities in early development

·         Structures which have different mature forms but develop from the same embryonic tissues, are called homologous structures

·         Vestigial organs may resemble miniature legs, tails, or other structures

·         Summary of Darwin’s Theory:

1.        Individual organisms in nature differ from one another. Some of this variation inherited

2.        Organisms in nature produce more offspring than can survive, and many of those that survive do not reproduce

3.        Because more organisms are produced than can survive, members of each species must compete for limited resources

4.        Because each organism is unique, each has different advantages and disadvantages in the struggle for existence

5.        Individuals best suited to their environment survive and reproduce most successfully. The characteristics that make them best suited to their environment are passed on to offspring. Individuals whose characteristics are not as well suited to their environment die or leave fewer offspring

6.        Species change over time. Over long periods, natural selection causes changes in the characteristics of a species, such as size and form. New species arise, and other species disappear

7.        Species alive today have descended with modification from species that lived in the past

8.        All organisms on Earth are united into a single tree of life by common descent

 

Chapter 16—Genes and Variation

 

·         A gene pool is the combined genetic information of all the members of a particular

·         The relative frequency of an allele is the number of times that allele occurs in a gene pool compared with the number of times other alleles occur

·         The tow main sources of genetic variation are mutations and the genetic shuffling that results from sexual production

·         The number of phenotypes produced for a given train depends on how many genes control the trait

·         A single-gene trait is controlled by a single gene that has two alleles

·         Most alleles are controlled by two or more genes and are called polygenic traits

·         Natural selection on single-gene traits can lead to changed in allele frequencies and thus to evolution

·         Natural selection can affect the distributions of phenotypes in any of three ways: directional selection, stabilizing selection, or disruptive selection

·         When individuals at one end of the curve have higher fitness than individuals in the middle or at the other end, directional selection takes place

·         When individuals near the center of the curve have higher fitness than individuals at either end of the curve, stabilizing selection takes place

·         When individuals at the upper and lower ends of the curve have higher fitness than individuals near the middle, disruptive selection takes place

·         Random change in allele frequency is know as genetic drift

·         In small populations, individuals that carry a particular allele may leave more descendants than other individuals, just by chance. Over time, a series of chance occurrences of this type can cause an allele to become common in a population

·         A situation in which allele frequencies change as a result of the migration of a small subgroup of a population is known as the founder effect

·         The Hardy-Weinberg principle states that allele frequencies in a population will remain constant unless one or more factors cause those frequencies to change

·         The situation in which allele frequencies remain constant is called genetic equilibrium

·         Five conditions are required to maintain genetic equilibrium from generation to generation: There must be random mating; the population must be very large; and there can be no movement into or out of the population, no mutations, and no natural selection

·         The formation of new species-speciation

·         As new species evolve, populations become reproductively isolated from each other

·         When the members of  two populations cannot interbreed and produce fertile offspring, reproductive isolation has occurred

·         One type of isolating mechanism, behavioral isolation, occurs when two populations are capable of interbreeding but have differences in courtship rituals or other types of behaviors

·         With geographic isolation, two populations are separated by geographic barriers such as rivers, mountains, or bodies of water

·         A third isolating mechanism is temporal isolation, in which two or more species reproduce at different times

·         Speciation in the Galapagos finches occurred by founding of a new population, geographic isolation changes in the new population’s gene pool, reproductive isolation, and ecological competition

 

Chapter 17-1—The Fossil Record

 

 

Chapter 17-4—Patterns of Evolution

 

 

Chapter 18—Classification

·         To study the diversity of life, biologists use a classification system to name organisms and group them in a logical manner

·         In the discipline known as taxonomy, scientists classify organisms and assign each organism a universally accepted name

·         Binomial nomenclature-two word naming system

·         In binomial nomenclature, each species is assigned a two-part scientific name

·         A genus is a group of closely related species

·         Linnaeus’s system of classification uses seven taxonomic categories—species, genus, family, order, class, phylum, and kingdom (King Phillip comes over for good sex)

·         Biologists now group organisms into categories that represent lines of evolutionary descent, not just physical similarities

·         This strategy of grouping organisms together based on their evolutionary history is called evolutionary classification

·         Characteristics that appear in recent parts of a lineage but not in its older members are called derived characters

·         Derived characters can be used to construct a cladogram, a diagram that shows the evolutionary relationship among a group of organisms

·         The genes of many organisms show important similarities at the molecular level. These similarities can be used as criteria to help determine classification

·         A model known as a molecular clock uses DNA comparisons to estimate the length of time that two species have been evolving independently

·         The six kingdom system of classification includes the kingdoms Eubacteria, Archaebacteria, Protista, Fungi, Plantae, and Animalia

·         The domain is more inclusive category than any other—larger than a kingdom

·         The three domains are: Bacteria, Archaea, and Eukarya

·         The members of the domains Bacteria and Archaea are unicellular and prokaryotic

·         The domain Eukarya consists of all organisms that have a nucleus

·         Protista—junk drawer domain

·         Fungi—heterotrophic

·         Plantae, multicellular  organisms that are photosynthetic autotrophs

·         Animalia, multicellular and heterotrophic

Chapter 32-3—Primates and Human Origins 

·         In general, primates have binocular vision, a well-developed cerebrum, fingers and toes, and arms that can rotate around their shoulder joints

·         Binocular vision is the ability to merge visual images from both eyes, therefore  providing depth perception

·         Primates that evolved from two of the earliest branches look very little like typical monkeys are called prosimians. Members of the more familiar primate group that includes monkeys, apes, and humans are called anthropoids

·         Prosimians alive today are small, nocturnal primates with large eyes that are adapted to seeing in the dark

·         Humans, apes, and most monkeys belong to a group called anthropoids

·         A prehensile tail is a tail that can coil tightly enough around a branch to serve as a fifth hand

·         Great apes, also called hominoids, include gibbons, orangutans, gorillas, chimps

·         The hominid family, which includes modern humans displayed several distinct evolutionary trends

·         Bipedal-two foot

·         Opposable thumb-enables grasping objects and using tools

·         Today most paleontologists agree that the hominid fossil record includes 5 genera—Ardipithecus, Australopithecus, Paranthropus, Kenyanthropus, and Homo—and as many as 16 separate hominid species. This diverse group of fossils covers roughly 4.5 million years

 

Chapter 35-2—The Nervous System

 

·         The nervous system controls and coordinates functions throughout the body and responds to internal and external stimuli

·         The cells that transmit impulses are called neurons

·         The largest part of a typical neuron is the cell body

·         Spreading out from the cell body are short, branched extensions called dendrites

·         The long fiber that carries impulses away from the cell body is called the axon

·         The axon is surrounded by an insulating membrane known as the myelin sheath

·         An impulse begins when a neuron is stimulated by another neuron or by the environment

·         The minimal level of a stimulus that is required to activate a neuron is called the threshold

·         Neurotransmitters are chemicals used by a neuron to transmit an impulse across a synapse to another cell

 

Chapter 35-3—Divisions of the Nervous System

 

·                     The central nervous system relays messages, processes information, and analyzes information

·         The central nervous system consists of the brain, and the spinal cord

·         The largest and most prominent region of the human brain is the cerebrum

·         The second largest region of the brain is the cerebellum

·         The brain stem connects the brain and spinal cord

·         The thalamus receives messages from the sense organs

·         The hypothalamus is the control center for recognition and analysis of hunger, thirst, fatigue, anger, and body temperature

·         A reflex is a quick, automatic response to a stimulus

·         The sensory division of the peripheral nervous system transmits impulses from the sense organs to the central nervous system to the muscles or glands



 Chapter 40—Endocrine and Reproductive Systems/The Immune System and Disease