5105365
| Question | Answer |
| Gene | A region of the chromosome that codes for a particular characteristic. ( Eye, Color, Blood Type) |
| Homozygous | When the two alleles for a particular characteristic are the same |
| Heterozygous | When the two alleles for a particular characteristic are different |
| Genotype | An organism’s genetic makeup (the two alleles that it possesses for each characteristic) |
| Phenotype | An organism’s actual physical traits |
| Dominant allele | An allele that is observed or expressed in the phenotype of a heterozygous individual. A dominant allele is represented by a capital letter (ex: “A”) |
| Recessive Allele | An allele that is not observed in the phenotype of a heterozygous individual. A recessive allele is represented by a lower case letter (ex: “a”) |
| Monohybrid Crosses | Examine only one characteristic, controlled by one gene (Ex. plant height) |
| Dihybrid Cross | Is a cross that looks at two different characteristics. Ex. Plant color and Plant Height |
| Autosomes | chromosomes other than the two sex chromosomes |
| P Generation | The Parent generation |
| F1 Generation | The first generation offspring. Offspring of Parent generation |
| F2 Generation | The generation after the F1 generation |
| Sex chromosomes | Is a type of chromosome that participates in sex determination. Humans and most other mammals have two sex chromosomes, the X and the Y |
| Sex-linked gene | Any gene located on a sex chromosome |
| Sex-linked traits | Sex-linked characteristics are determined by genes on the X chromosome. |
| Complete dominance | The phenotype of the homozygote is complete and doesn't share phenotypes |
| incomplete dominance | the phenotype of a heterozygote is in between the phenotypes of the two homozygotes (Straight Hair+ Wavy Hair =Curly Hair) |
| Codominance | : both alleles are fully expressed in heterozygous ( Red Flower + White Flower= Red and White Flower) |
| Pleiotropy | is when one gene has many phenotypic effects |
| Polygenic traits | are influenced by more than one gene |
| Linked genes | are genes that are located close together on the same chromosome |
| When do you see a recessive trait expressed in the phenotype of an individual? | When both gametes from the parents are recessive |
| Dihybrid crosses | one 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 |
| Sex-linked recessive traits | a carrier mother x normal father, a normal mother x affected father, a carrier mother x affected father |
| Explain what a test cross | The mating between a homozygous recessive and a dominant phenotype(Rr/RR) |
| How to interpret the results of a test cross | If 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) |
| Describe why most human genetic diseases are recessive and rare | Because of non-functional “clunker” alleles (nn/ Carrier=Nn) |
| If a disease is recessive, how is an individual affected | an individual can be a “carrier” of the abnormal allele. A carrier is not affected by the disease, but has the allele |
| Why don't dominant diseases or traits do not skip a generation | Recessive clunker alleles can be carriers and not affect the person while a dominant will get it no matter what |
| Give 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 |
| Explain what determines the sex of a child | Females 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 |
| Be 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 |
| Explain what Mendel’s Law (Principle) of Independent Assortment states | the 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 |
| Under 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. |
| Explain the main advantage of sexual reproduction, as opposed to asexual reproduction | Sexual 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 |
| Symbiosis | is a close and long-term interaction between two different species |
| mutualism | in which both species involved in the relationship benefit from it. |
| Flowering plants and their animal pollinators are an example of a type of symbiosis called mutualism | yes |
| how each species benefits from the relationship of mutualism (Plants and Animals) | Animals get food called nectar while plants are able to pollinate and reproduce. |
| Explain the function of flowers | The produce nectar that feeds animals and also attract them so that they can pollinate through anoimals |
| Where does meiosis occur, and what is the end result of meiosis (pLants) | The anther and produces pollen grains |
| Describe the characteristics of wind-pollinated plants, in terms of their pollen and flowers | usually have small, inconspicuous flowers and produce large amounts of pollen. |
| Describe 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. |
| Coevolution | where two species reciprocally affect each others’ evolution |
| Be able to describe the symbiosis between flowering plants and their pollinator | They have used mutualism to help each other. The flower pollinates and the animal gets food in the form of nectar |
| and 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 |
| Where does fertilization occur in a flower | Ovule (The zygote develops into an embryo. The ovule develops into a seed. The seed contains an embryo, nutritive material, and a protective coat.) |
| Describe the three main parts of a seed. | The seed contains an embryo, nutritive material, and a protective coat |
| What 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 |
| Describe which parts of the human life cycle are diploid, and which are haploid | Diploid body cells containing two sets of chromosomes and Haploid gametes that have only one set of chromosomes |
| Where does meiosis occur in males | within tiny tubules in the testis |
| Where does meiosis occur in females | begins in the ovaries before a girl is born, and is not actually completed until after fertilization occurs. |
| What is the end-product of meiosis in males | : each episode of meiosis results in four haploid sperm cells being formed |
| What is the end-product of meiosis in females | produce egg cells |
| In 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. |
| Describe the relationship between nucleotides and nucleic acids | DNA and RNA are a type of molecule called nucleic acids. They are made of chemical building blocks called nucleotides. |
| and the three main parts of a nucleotide | Each nucleotide has a 5 Carbon Sugar, a Phosphate and a Base |
| Explain 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 |
| Describe the arrangement of nucleotides in a molecule of DNA | DNA ATCG /RNA AUCG DNA A/T or C/G |
| What makes up the long sides of the molecule | The sides represent the sugar-phosphate backbones |
| .? What forms the “rungs” of the ladder? | Each wooden rung represents a pair of bases connected by hydrogen bonds |
| Describe the pattern of how nucleotide bases pair up | DNA: A/T or C/G RNA and DNA: A/U C/G |
| the role of hydrogen bonds in the DNA molecule | hold the base pairs together. A hydrogen bond is a type of weak chemical bond |
| . 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) |
| Describe the process of DNA replication | the 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 |
| What role does the enzyme DNA polymerase play in DNA replication | An 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 |
| How does each existing strand determine the sequence of bases in the new strands that are formed | DNA replication ensures that all the body cells in multicellular organisms carry the same genetic information. |
| Explain 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 |
| Explain the relationship between DNA, chromosomes and genes | DNA 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 |
| Explain the relationship between amino acids and proteins | A 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. |
| Give 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 |
| Describe the process of transcription and the process of translation | Transcription 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 |
| where in the cell does transcritpiton happen | Nucleus |
| where in the cell does translation happen | Cytoplasm |
| Describe the role of mRNA, tRNA, and the ribosome in translation | The 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 |
| Describe the role of RNA polymerase in transcription | An enzyme named RNA polymerase attaches to one of the two strands of DNA (the “template strand” to the RNA strand |
| Describe where a codon is found | mRNA |
| tRNA | Acts 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) |
| what a codon “codes” for | Each codon “codes for” one specific amino acid in the protein being produced |
| Where are anti-codons found | tRNA |
| Explain what is meant by the statement that “the genetic code is universal | Almost 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. |
| Describe what a mutation is | is any change in the nucleotide base sequence of DNA. usually change the sequence of amino acids in the protein coded for by the gene. |
| explain how substitution mutations or insertion/deletion mutations in a gene can affect the protein that is coded for by the gene | Insertions 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. |
| nucleotide substitutions | the replacement of one base by another |
| nucleotide deletions or insertion | (the loss or addition of a nucleotide). |
| Which type of mutations are likely to have the biggest effect on the protein coded for by the gene, and why | Insertions 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 |
| Describe the source of NEW alleles in a species. | Mutations are the ultimate source of all new alleles and variation |
| What is a mutagen | physical or chemical agents that cause changes in DNA |
| Describe the structure of a typical virus | possess 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. |
| . Are viruses made of cells | are not made of cells |
| Why are viruses generally not considered to be living things | cannot reproduce on their own: require a living “host” cell in order to replicate |
| What must a virus do in order to replicate itself | require a living “host” cell in order to replicate |
| Be able to explain the events that occur with viral infection of a cell and replication | genetic 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 |
| What is the difference between a DNA virus and an RNA virus | DNA virus replicates DNA (Reverse Transcriptise) while RNAreplicates RNA |
| What is a retrovirus | retrovirus is an RNA virus that uses its own RNA to make a molecule of DNA |
| Is HIV a DNA virus or an RNA virus | RNA Virus |
| What type of cell does this virus (HIV) infect | of white blood cells that are important in the body’s immune system. |
| pro virus | The DNA produced from the viral genes then enters the nucleus and inserts itself into the host cell’s chromosome as a “provirus |
| How is it that new viruses such as HIV or the H1N1 flu virus suddenly appear in the human population? | Mutations |
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