BSC Exam 2 Study Guide Questions And Guaranteed Correct Answers

Deoxyribose sugar and double stranded - Correct Answers Structural characteristics of DNA Double helix structure (2 polynucleotides), strands are complementary (4 nitrogenous bases), and connected by hydrogen bonds - Correct Answers What were the main characteristics described by Watson and Crick? A semiconservative molecule - Correct Answers What characteristics allow for DNA synthesis? Adenine-Thymine Cytosine-Guanine - Correct Answers Complementary base pairing - which ones always pair? RNA replaces Thymine with Uracil and is single stranded - Correct Answers How are DNA and RNA different? DNA - RNA - Protein - Correct Answers What is the correct order of the flow of information to make proteins? Transcription and translation - Correct Answers What processes are involved in the making of proteins? Types of mutations - Correct Answers Negative, neutral, or beneficial Chromosomal mutation - Correct Answers Affecting whole or a part of a chromosome Gene mutation - Correct Answers Changes to the bases in DNA of one gene Nonsense mutation - Correct Answers Mutated codon is a premature stop codon Missense mutation - Correct Answers Mutated codon codes for a different amino acid Silent mutation - Correct Answers Mutated codon codes for the same amino acid DNA - Correct AnswersDeoxyribose sugar double helix. Set of nucleotides that contain genetic material inherited from parents. Polymer. RNA - Correct AnswersRibose sugar single helix. Sets of nucleotides that contain genetic information. Polymer. Ribonucleic acid, 3 types: messenger, transfer, and ribosomal. Nucleotides - Correct AnswersStructural components/building blocks of DNA and RNA. A nucleotide consists of a base (adenine, thymine, guanine, and cytosine) plus a molecule of sugar and one of phosphoric acid. Monomers. Polymer - Correct AnswersPolynucleic acid. 5 carbon sugar, phosphate group joined by dehydration reaction, and nitrogenous base. Codons, proof-reading - Correct AnswersImportant characteristics of the genetic code to prevent mistakes in protein synthesis Nitrogenous bases - Correct Answersa nitrogen containing molecule that has the same chemical properties as a base. Adenine, guanine, cytosine, thymine, and uracil. Codons - Correct Answersa sequence of three DNA or RNA nucleotides that corresponds with a specific amino acid or stop signal during protein synthesis Advantages of asexual reproduction - Correct AnswersReproduce without a mate Produce many offspring quickly No energy invested in gamete production or mating Optimal genetics for environment Disadvantages of asexual reproduction - Correct AnswersGenetically uniform populations (no genetic diversity) Advantages of sexual reproduction - Correct AnswersHigh genetic variability among offspring, greater chance for adaptation for changing environment Disadvantages of sexual reproduction - Correct AnswersMust fine mate Individual transmits 1/2 of genetic information to next generation Slower growth rate of population High energy requirements for courtship and gamete production G1 and G2 phases - Correct AnswersGrowth of cell (increase cytoplasm, increase proteins, produce organelles) S phase - Correct AnswersDNA synthesis (DNA is replicated in the nucleus) M phase - Correct AnswersMitosis = nuclear division The purpose of mitosis is regeneration, growth, and asexual reproduction. Cells go through this to replace cells after damage, grow individuals, and produce new individuals that are identical to the parent cells - Correct AnswersWhat is the purpose of mitosis? What are the reasons cells go through mitosis? Prophase - Correct AnswersChromosomes become visible, nuclear envelope dissolves, spindle forms. Chromosomes are threadlike chromatin. This is the first stage where chromosomes are visible. Metaphase - Correct AnswersChromosomes line up on the metaphase plate (the center of the cell). Anaphase - Correct AnswersSister chromatids separate and move towards the poles Telophase - Correct AnswersChromosomes are at the poles. Nuclear envelope (nucleus) forms. Cytokinesis - Correct AnswersDivision into two daughter cells is completed, cytoplasm divides. Two diploid cells - Correct AnswersHow many cells are produced by mitosis and are they haploid or diploid? Cells lack protein checkpoints and produce own growth factors - Correct AnswersWhat makes cancer cells different from normal cells? The purpose of meiosis is to reduce the normal diploid cells to haploid cells, called gametes - Correct AnswersWhat is the purpose of meiosis? Two cellular divisions occur in meiosis. In Meiosis 1 (Anaphase 1) homologous chromosomes are separated and in Meiosis 2 (Anaphase 2) sister chromatids are split. - Correct AnswersHow many cellular divisions occur in meiosis? What is separated in each stage? Four haploid cells. - Correct AnswersHow many cells are produced by meiosis? Are the cells diploid or haploid? Homologous chromosomes - Correct AnswersPair of chromosomes with same genes Sister chromatids - Correct AnswersIdentical copies (chromatids) formed by the DNA replication of a chromosome, with both copies joined together by a common centromere Haploid - Correct Answersn (number of pairs) Diploid - Correct Answers2n (number of chromosomes) Asexual reproduction - Correct AnswersType of reproduction by which offspring arise from a single organism. Fission, budding, fragmentation and regeneration Germ cells - Correct AnswersCells that give rise to gametes Somatic cells - Correct AnswersAll body cells except germ cells Gametes - Correct AnswersA mature haploid female or male germ cell which is able to unite with another of the opposite sex in sexual reproduction to form a zygote Sexual reproduction - Correct AnswersGametes fuse to create zygote. Produces new individuals that are different from parent cells. 1. Independent orientation of chromosomes (Mendel's Law of Independent Assortment) 2. Random Fertilization 3. Crossing Over - Correct AnswersWhat 3 processes increase genetic diversity? Complete dominance - Correct AnswersWhen the one allele completely covers up the other allele Codominance - Correct AnswersWhen two or more alleles are dominant incomplete dominance - Correct AnswersSituation in which one allele is not completely dominant over another allele. Phenotype expression of recessive not completely masked in heterozygote. Parents pass on "heritable factors" onto offspring. Heritable factors may be rearranged, but retain identity from one generation to the next. - Correct AnswersGregor Mendel and contributions to understanding patterns of inheritance It decreases genetic diversity, increases the frequency of recessive genotypes causing genetic diversity, and exposes rare recessive mutations. - Correct AnswersWhy does inbreeding actually cause decreased health and fitness in populations? Crossing over - Correct AnswersProcess in which homologous chromosomes exchange portions of their chromatids during meiosis. Exchange of genetic information. Occurs during Prophase I in meiosis. Homologous chromosomes pair up and form tetrads. Sister chromatids from 2 chromosomes "cross over" at chiasmata. Homozygous - Correct AnswersAlleles are the same Heterozygous - Correct AnswersAlleles are different Dominant - Correct AnswersDetermines appearance of offspring if present Recessive - Correct AnswersMasked by dominant allele. Only determines appearance if both alleles are recessive. Genotype - Correct AnswersAlleles present in offspring for character Phenotype - Correct AnswersPhysical appearance as a result of alleles Allele - Correct AnswersAlternative forms of genes Inbreeding - Correct AnswersReproduction between related individuals It explains biodiversity, relationship between living organisms, and why/how organisms are well-suited to so many different environments. - Correct AnswersWhy is evolution considered a unifying theory of biology? 1. Animals and plants had characteristics specific to the environment they inhabited. 2. Organisms were similar but different from organisms on the mainland. - Correct AnswersWhat were the 2 big observations Darwin made while on the HMS Beagle? Current species came from a succession of ancestors. Descendants accumulated adaptations as a result of changing environmental factors. Resulted in new species and increased diversity. - Correct AnswersWhat is descent with modification? Reproduction, hereditary, variation in fitness or organisms, variation in individual character among members of the population. Unequal reproduction is essential. Individuals with characteristics allowing them to be better at: - Getting food - Escaping predators - Tolerating environment - Attracting mates ...will survive longer and potentially produce more offspring with the adaptive characteristic. - Correct AnswersHow does natural selection