UCI Bio 93 Final Exam Questions With 100% Correct Answers 2024

UCI Bio 93 Final Exam Questions With 100% Correct Answers 2024 What are the four most common elements in living matter? - answerHydrogen, Oxygen, Nitrogen, and Carbon --make up 96% of all living matter. Properties of Acids - answerDonate H+ to a solution, accept electrons, and have a pH of <7 What happens in the S phase of the cell cycle? - answerDNA Synthesis What happens in the G1 phase of the cell cycle? - answerGrowth -- cell contents are duplicated. What happens in the G2 phase of the cell cycle? - answerMore growth and preparation for division. What happens in the M phase of the cell cycle? - answerMitosis (and cytokinesis -- division of the cell). What are the subphases of mitosis? - answerProphase, Pre-metaphase, Metaphase, Anaphase, and Telophase. How many checkpoints are there in the cell cycle? - answer3 -- G1 checkpoint, G2 checkpoint, and the M checkpoint. What is a Karyotype? - answerA layout of Metaphase chromosomes matched with their homologous pairs. What is a diploid cell? - answerA cell with 46 chromosomes -- somatic cells. What is a haploid cell? - answerA cell with 23 chromosomes -- sex cells. What does the mesoderm give rise to? - answerthe notochord (similar to a spinal chord). What does the endoderm give rise to? - answerthe digestive tract. What does the ectoderm give rise to? - answerthe nervous system (brain)/neural plate. If 2n = 18, how many chromosomes come from the mother? - answer9 -- half from mom and half from dad Meiosis - answerMeiosis is a specialized type of cell division that reduces the chromosome number by half, creating four haploid cells, each genetically distinct from the parent cell that gave rise to them. What two structures does the chiasma connect? - answerNon-sister chromatids. What are the steps of meiosis? - answerProphase I, Metaphase I, Anaphase I, Telophase I & cytokinesis (then a second set of phases) What does meiosis 1 deal with? - answerhomologous chromosomes. What happens in prophase 1? - answerThe chromosomes condense, the nuclear envelope breaks down, chromosomes cross over, and meiotic spindle forms. What happens in metaphase 1? - answerthe pairs of homologous chromosomes are now tightly condensed and coiled and become arranged on the metaphase plate. What happens in anaphase 1? - answerthe pairs of chromosomes are pulled apart by the spindle fibers (microtubules). What happens in Telophase 1 and cytokinesis? - answerThe homologous chromosome pairs complete their migration to the two poles as a result of the action of the spindle. Now a haploid set of chromosomes is at each pole, with each chromosome still having two chromatids. A nuclear envelope reforms around each chromosome set, the spindle disappears, and cytokinesis follows. What happens during meiosis 2? - answersister chromatids separate. What happens in prophase 2 of meiosis? - answerA new spindle forms around the chromosomes. What happens in metaphase 2 of meiosis? - answerMetaphase 2 chromosomes line up at the equator. What happens in anaphase 2 of meiosis? - answerCentromeres divide chromatids move to opposite poles of the cells. What happens during telophase 2 of meiosis? - answerA nuclear envelope forms around each set of chromosomes and the cytoplasm divides. What makes meiosis a unique form of cell division - answerSynapsis and crossing over -- occurs in prophase 1, pairing up of homologous chromosomes, homologous chromosomes cross over and exchange corresponding genetic information (the DNA exchanged contain the same genes, but may have different alleles). How does meiosis increase genetic variability? - answerIndependent assortment (meiosis 1 -- homologous chromosomes separate independently), crossing over (genetic recombination, prophase 1), and random fertilization (any egg can join with any sperm -- most effective way to obtain genetic variability). What is the law of segregation? - answerAlleles coding for the same trait separate independently during gamete formation. What is non-disjunction? - answerWhen homologous chromosomes or sister chromatids do not separate properly. What is a character? - answerAn observable heritable feature that may vary among individuals. Ex: flower color. What is a trait? - answerOne of two or more detectable variants in a genetic character. Ex: purple flower color/white flower color. What does the blending theory state? Is this true? - answerThe offspring is a blend of both parents (ex: a tall mom giraffe + a short dad giraffe = a medium height giraffe). This is not true because if so, every single offspring would look the same. What does particulate inheritance state? Is this true? - answerDifferent traits are inherited in separate distinct units (genes) (ex: F1 and F2 generations). This is always true because of not every offspring looks the exact same (has the exact same genetics). What is an allele? - answerAn alternate form of a gene (ex: the gene that determines hair color). What does the Law of Segregation state? - answerThe Law of Segregation states that two alleles in a pair segregate into different gametes. (this deals with separation of homologous pairs in Meiosis 1 producing haploid daughter cells after Meiosis 1). What does Independent Assortment state? - answerEach pair of alleles assort/segregate separately from each other during gamete formation. AKA no gene linkage. What did Mendelian Genetics assume? - answerGregor Mendel, through his work on pea plants, discovered the fundamental laws of inheritance. He deduced that genes come in pairs and are inherited as distinct units, one from each parent. Mendel tracked the segregation of parental genes and their appearance in the offspring as dominant or recessive traits. What is a dominant allele? - answerAn allele that is fully expressed in the phenotype of the heterozygote. What is a recessive allele? - answerAn allele whose phenotypic effect is not observed in the heterozygote.