Fichas
Bio Sci Exam 3
Fichas del conjunto (100)
- 1GeneA region of the chromosome that codes for a particular characteristic. ( Eye, Color, Blood Type)
- 2HomozygousWhen the two alleles for a particular characteristic are the same
- 3HeterozygousWhen the two alleles for a particular characteristic are different
- 4GenotypeAn organism’s genetic makeup (the two alleles that it possesses for each characteristic)
- 5PhenotypeAn organism’s actual physical traits
- 6Dominant alleleAn allele that is observed or expressed in the phenotype of a heterozygous individual. A dominant allele is represented by a capital letter (ex: “A”)
- 7Recessive AlleleAn allele that is not observed in the phenotype of a heterozygous individual. A recessive allele is represented by a lower case letter (ex: “a”)
- 8Monohybrid CrossesExamine only one characteristic, controlled by one gene (Ex. plant height)
- 9Dihybrid CrossIs a cross that looks at two different characteristics. Ex. Plant color and Plant Height
- 10Autosomeschromosomes other than the two sex chromosomes
- 11P GenerationThe Parent generation
- 12F1 GenerationThe first generation offspring. Offspring of Parent generation
- 13F2 GenerationThe generation after the F1 generation
- 14Sex chromosomesIs a type of chromosome that participates in sex determination. Humans and most other mammals have two sex chromosomes, the X and the Y
- 15Sex-linked geneAny gene located on a sex chromosome
- 16Sex-linked traitsSex-linked characteristics are determined by genes on the X chromosome.
- 17incomplete dominancethe phenotype of a heterozygote is in between the phenotypes of the two homozygotes (Straight Hair+ Wavy Hair =Curly Hair)
- 18Complete dominanceThe phenotype of the homozygote is complete and doesn't share phenotypes
- 19Codominance: both alleles are fully expressed in heterozygous ( Red Flower + White Flower= Red and White Flower)
- 20Pleiotropyis when one gene has many phenotypic effects
- 21Polygenic traitsare influenced by more than one gene
- 22Linked genesare genes that are located close together on the same chromosome
- 23When do you see a recessive trait expressed in the phenotype of an individual?When both gametes from the parents are recessive
- 24Dihybrid crossesone parent who is homozygous dominant for both traits x one parent who is homozygous recessive for both traits, parents who are both heterozygous for both traits, one parent who is heterozygous for both traits x one parent who is homozygous recessive for both traits
- 25Sex-linked recessive traitsa carrier mother x normal father, a normal mother x affected father, a carrier mother x affected father
- 26Explain what a test crossThe mating between a homozygous recessive and a dominant phenotype(Rr/RR)
- 27How to interpret the results of a test crossIf an individual shows the dominant phenotype, you cannot tell by their appearance whether they are homozygous dominant or heterozygous (Pp/PP) Phenotypes of offspring tell us what they are (homozygous dominant or heterozygous)
- 28Describe why most human genetic diseases are recessive and rareBecause of non-functional “clunker” alleles (nn/ Carrier=Nn)
- 29If a disease is recessive, how is an individual affectedan individual can be a “carrier” of the abnormal allele. A carrier is not affected by the disease, but has the allele
- 30Why don't dominant diseases or traits do not skip a generationRecessive clunker alleles can be carriers and not affect the person while a dominant will get it no matter what
- 31Give some examples of polygenic traits, and traits that are influenced by both genes and environmental factors in humans.Skin color, Height, things affected by Heredity and Environment
- 32Explain what determines the sex of a childFemales have two X chromosomes, males have an X and a Y. Males determine sex of child because they can give an X or Y chromosome
- 33Be able to explain why sex-linked traits are observed more often in males than in females(Women have two X chromosomes: they have two chances to get the normal allele for each gene carried on the X, whereas men only have one.)Most of these disorders are recessive (like most genetic diseases. Sex-linked genes are located on the X chromosome
- 34Explain what Mendel’s Law (Principle) of Independent Assortment statesthe
alleles for each characteristic are passed down independently of
each other: all four possible gamete types are made in equal numbers
Two genes that are located on different chromosomes will always show independent assortment - 35Under what circumstances will the alleles of two different genes NOT show Independent Assortment, and why not?Genes that are located near each other on the same chromosome will not show independent assortment: the alleles present on the same chromosome will tend to be passed down together (genes C and D)—they are linked.
- 36Explain the main advantage of sexual reproduction, as opposed to asexual reproductionSexual reproduction gives an evolutionary advantage by providing increased genetic variation: each offspring is genetically different from the parents, and from each otherGenetic variation makes adaptation to a changing environment more possible
- 37Symbiosisis a close and long-term interaction between two different species
- 38mutualismin which both species involved in the relationship benefit from it.
- 39Flowering plants and their animal pollinators are an example of a type of symbiosis called mutualismyes
- 40how each species benefits from the relationship of mutualism (Plants and Animals)Animals get food called nectar while plants are able to pollinate and reproduce.
- 41Explain the function of flowersThe produce nectar that feeds animals and also attract them so that they can pollinate through anoimals
- 42Where does meiosis occur, and what is the end result of meiosis (pLants)The anther and produces pollen grains
- 43Describe the characteristics of wind-pollinated plants, in terms of their pollen and flowersusually have small, inconspicuous flowers and produce large amounts of pollen.
- 44Describe the general characteristics of animal-pollinated plants.Many plants have flowers that have evolved to attract specific animal pollinators (insects, birds, bats) shape/color/structure of flowers are often adaptations to attract a specific type of pollinator.
- 45Coevolutionwhere two species reciprocally affect each others’ evolution
- 46Be able to describe the symbiosis between flowering plants and their pollinatorThey have used mutualism to help each other. The flower pollinates and the animal gets food in the form of nectar
- 47and how they have undergone coevolution and have changed because of their relationship with each other. (Plants and animals)The shape/color/structure of flowers are often adaptations to attract a specific type of pollinator.
Pollinators often show specific adaptations to help them find & gain access to nectar from the flowers they pollinate - 48Where does fertilization occur in a flowerOvule (The zygote develops into an embryo.
The ovule develops into a seed.
The seed contains an embryo, nutritive material, and a protective coat.) - 49Describe the three main parts of a seed.The seed contains an embryo, nutritive material, and a protective coat
- 50What is the main function of a fruit?helps protect the seed,
increases seed dispersal either by wind, or by being dispersed by animals, and
is often a major food source for animals - 51Describe which parts of the human life cycle are diploid, and which are haploidDiploid body cells containing two sets of chromosomes and
Haploid gametes that have only one set of chromosomes - 52Where does meiosis occur in maleswithin tiny tubules in the testis
- 53Where does meiosis occur in femalesbegins in the ovaries before a girl is born, and is not actually completed until after fertilization occurs.
- 54What is the end-product of meiosis in males: each episode of meiosis results in four haploid sperm cells being formed
- 55What is the end-product of meiosis in femalesproduce egg cells
- 56In what four ways are sperm cells specialized for the function of reaching and fertilizing an egg?Have Haploid chromosome number (23)
Grow a flagellum to swim up female repro tract to reach egg.Get rid of most of their cytoplasm (for speed!)Specialized packet of enzymes at the head of the sperm (acrosome), to penetrate outer layers of egg. - 57Describe the relationship between nucleotides and nucleic acidsDNA and RNA are a type of molecule called nucleic acids.
They are made of chemical building blocks called nucleotides. - 58and the three main parts of a nucleotideEach nucleotide has a 5 Carbon Sugar, a Phosphate and a Base
- 59Explain the important differences between DNA and RNA in terms of their chemical structure.DNA CTAG and RNA has a U for T (CUAG). DNA two strands/RNA one strand
SUgars
DNA;Deuxyribose RNA; Ribose - 60Describe the arrangement of nucleotides in a molecule of DNADNA ATCG /RNA AUCG
DNA A/T or C/G - 61What makes up the long sides of the moleculeThe sides represent the sugar-phosphate backbones
- 62.? What forms the “rungs” of the ladder?Each wooden rung represents a pair of bases connected by hydrogen bonds
- 63Describe the pattern of how nucleotide bases pair upDNA: A/T or C/G
RNA and DNA: A/U C/G - 64the role of hydrogen bonds in the DNA moleculehold the base pairs together. A hydrogen bond is a type of weak chemical bond
- 65. What part of the molecule determines a person's genetic code?It is the order/sequence of nucleotide bases along the strand of DNA that encodes all of an individual’s genetic information (ATCG)
- 66Describe the process of DNA replicationthe two strands of a DNA molecule “unzip”. Each seperate strand serves as a template for a new, complementary strand, according to base pairing rules.this process will be identical to each other and to the original, but will each be made up of one old strand and one new strand
- 67What role does the enzyme DNA polymerase play in DNA replicationAn enzyme called DNA polymerase links together the nucleotides of the new strands of DNA.make the covalent bonds between the nucleotides of a new DNA strand, and
are also involved in repairing damaged DNA - 68How does each existing strand determine the sequence of bases in the new strands that are formedDNA replication ensures that all the body cells in multicellular organisms carry the same genetic information.
- 69Explain why after DNA replication, each new molecule of DNA is half old and half new.Because it's a connection of a daughter strand and a parent strand
- 70Explain the relationship between DNA, chromosomes and genesDNA functions as the inherited directions for a cell or organism.a GENE is a region of a chromosome that codes for one specific characteristic in an organism. Chromosomes have DNA
- 71Explain the relationship between amino acids and proteinsA protein is made up of a long chain of amino acids in a very specific order. The chain then folds into a specific 3-dimensional shape, based on its amino acid sequence.
- 72Give some examples of how proteins serve very important functions in the body, including the function of enzymes.Blood and enzymes help lower activation energy for chemical reactions
- 73Describe the process of transcription and the process of translationTranscription involves the transfer of genetic information from DNA into a molecule of messenger RNA (mRNA
Translation involves the transfer of information from messenger RNA into a protein - 74where in the cell does transcritpiton happenNucleus
- 75where in the cell does translation happenCytoplasm
- 76Describe the role of mRNA, tRNA, and the ribosome in translationThe mRNA leaves the nucleus through pores in the nuclear membrane, and goes into the cytoplasm.The mRNA is “read” in groups of three bases: each group of three bases (triplets) is called a CODON.
Each codon “codes for” one specific amino acid in the protein being produced. MRNA is in ribosomes - 77Describe the role of RNA polymerase in transcriptionAn enzyme named RNA polymerase attaches to one of the two strands of DNA (the “template strand” to the RNA strand
- 78Describe where a codon is foundmRNA
- 79tRNAActs as a molecular interpreter (converts the language of nucleotide bases into the language of amino acids).
Has a specific three base “anticodon” on the one end, which is complementary to one specific codon in mRNA.
(MAKES PROTEINS by POLYPEPTIDES) - 80what a codon “codes” forEach codon “codes for” one specific amino acid in the protein being produced
- 81Where are anti-codons foundtRNA
- 82Explain what is meant by the statement that “the genetic code is universalAlmost all living organisms share the same genetic code, the set of rules relating nucleotide sequence in a strand of DNA/mRNA to the sequence of amino acids in the protein that it codes for.
- 83Describe what a mutation isis any change in the nucleotide base sequence of DNA. usually change the sequence of amino acids in the protein coded for by the gene.
- 84explain how substitution mutations or insertion/deletion mutations in a gene can affect the protein that is coded for by the geneInsertions and deletions change the reading frame of the genetic message and affect all amino acids “downstream”: Often lead to disastrous effects. Sutstitutions change ONE amino acid in the protein.
- 85nucleotide substitutionsthe replacement of one base by another
- 86nucleotide deletions or insertion(the loss or addition of a nucleotide).
- 87Which type of mutations are likely to have the biggest effect on the protein coded for by the gene, and whyInsertions and deletions generally have a much larger effect on the protein they code for than substitutions.
Insertions and deletions change the reading frame of the genetic message and affect all amino acids - 88Describe the source of NEW alleles in a species.Mutations are the ultimate source of all new alleles and variation
- 89What is a mutagenphysical or chemical agents that cause changes in DNA
- 90Describe the structure of a typical viruspossess genetic material in the form of nucleic acids (DNA or RNA) wrapped in a protein coat. Protein spikes on the outside of the virus are necessary to attach the virus to a “host” cell to infect it.
- 91. Are viruses made of cellsare not made of cells
- 92Why are viruses generally not considered to be living thingscannot reproduce on their own: require a living “host” cell in order to replicate
- 93What must a virus do in order to replicate itselfrequire a living “host” cell in order to replicate
- 94Be able to explain the events that occur with viral infection of a cell and replicationgenetic material of the virus enters the cellThe virus’s genes code for the production of mRNA and also result in production of more viral genetic materialViral mRNA is translated into new viral proteinThe new viruses leave the cell, and go on to infect new host cells
- 95What is the difference between a DNA virus and an RNA virusDNA virus replicates DNA (Reverse Transcriptise) while RNAreplicates RNA
- 96What is a retrovirusretrovirus is an RNA virus that uses its own RNA to make a molecule of DNA
- 97Is HIV a DNA virus or an RNA virusRNA Virus
- 98What type of cell does this virus (HIV) infectof white blood cells that are important in the body’s immune system.
- 99pro virusThe DNA produced from the viral genes then enters the nucleus and inserts itself into the host cell’s chromosome as a “provirus
- 100How is it that new viruses such as HIV or the H1N1 flu virus suddenly appear in the human population?Mutations