Anna Montgomery BSC 109 Exam 4 Study Guide Chapter Nineteen 1 Who is considered the grandfather of genetics Gregor Mendel 2 What organism did he utilize to conduct his research Garden sweet peas 3 Know and understand Mendel s four hypotheses 4 Know the following terms There are alternative forms of genes the units that determine heritable traits For each inherited character an organism inherits two alleles one from each parent If the two alleles of an inherited pair differ then one determines the organism s appearance and is called the dominant allele the other has no noticeable effect on the organism s appearance and is called the recessive allele A sperm or egg carries only one allele for each inherited character because the two members of an allele pair separate from each other during the production of gametes Gene the units that determine heritable traits Allele Dominant one that determines the organism s appearance Recessive no noticeable effect on the organism s appearance Homozygous same alleles for a gene Heterozygous different alleles for a gene Genotype genetic makeup two copies each gene Phenotype physical traits True breeding Test cross mating between an individual of unknown genotype and homozygous recessive individual Parental p generation true breeding parents one white flower one purple flower F1 generation offspring from two different true breeding varieties F2 generation fertilization between F1 generation 5 Know how to work the following genetic problems Green G apples are dominant to red apples g What will be the genotypic and phenotypic ratio of the F1 generation of a cross between true breeding green and red apples What will be the genotypic and phenotypic ratios of the F2 generation You are walking down the road when you find a cute little brown bunny You know from previous bunny work that brown bunnies are dominant to white bunnies You want to determine the genotype of the brown bunny What do you do and how do you do it You do the experiment in number 3 and obtain the following data 32 brown bunnies and 0 white bunnies What is the genotype of the bunny you found Chapter Seventeen 1 Define asexual reproduction and sexual reproduction Asexual reproduction o Single celled organisms reproduce by simple cell division mitosis o No fertilization of an egg by a sperm o One parent and its offspring have identical genes Sea starts grow by fragmentation Clipping a plant and growing another asexual Sexual reproduction o Requires fertilization of an egg by a sperm using a special type of cell division meiosis o Use meiosis for reproduction o Uses mitosis for growth and maintenance 2 What is the benefit of sexual reproduction over asexual Increases diversity Organism is more protected 3 How many times does the DNA replicate in mitosis Once 4 Somatic vs germ cell Somatic body cell Germ cell produces either haploid egg or sperm cell o Only undergo mitosis o Undergoes meiosis 5 Haploid vs diploid Haploid o Have half the amount of chromosomes as diploid o Result of meiosis diploid cells divide and give rise to haploid germ cells o Two haploids merge during fertilization Diploid o Contain two complete sets of chromosomes o Reproduce by mitosis making daughter cells that are exact replicates 6 What are sister chromatids Before a cell divides it duplicates all of its chromosomes resulting in two copies 7 What is a centromere Sister chromatids are joined together at a narrow waist 8 What is a gene Gene is a physical and functional unit of heredity 9 What is an allele Allele is each version of a gene 10 How many chromosomes do humans have 46 22 match autosomes 23rd pair is the sex chromosomes 11 What are the phases of the cell cycle Interphase metabolism and growth 90 of time o Performs normal functions o Doubles everything in its cytoplasm o Grows in size Mitotic phase cell division 10 of time o Mitosis nucleus and its contents divide evenly into two daughter nuclei o Cytokinesis cytoplasm is divided in two 12 What are the phases of mitosis Prophase form chromosomes Metaphase chromosomes attach themselves to centromere and align themselves in middle Anaphase centromeres split sister chromosomes separate Telophase Cytokinesis nuclear envelope forming and cleavage furrow splitting forming two daughter cells 13 What is cytokinesis Occurs during telophase Divides cytoplasm 14 How is cytokinesis different in plants and animals In plants a cell plate begin to grow and elongate until splits two cells continues growing after to a new cell wall In animals cleavage furrow and continues to pinching until splits into two cells 15 What are homologous chromosomes Matching pairs of chromosomes Look similar they may posses the same genes but the genes may be different versions 16 What is a zygote Fertilized egg 17 What is a karyotype A method of organizing the chromosomes of a cell in relation to number size and type o The chromosomes are arrested in the metaphase stage of mitosis photographed and organized 18 What is crossing over and why is it important Homologous chromosomes exchange genetic information Genetic recombination occurs Contributes to genetic diversity 19 What is fertilization One haploid egg and one haploid sperm fuse together to form a zygote 20 When does crossing over occur Prophase 1 of meiosis 21 What are some key differences between mitosis and meiosis Mitosis o Prophase duplicated chromosomes o Metaphase chromosomes align at middle of cell o Anaphase Telophase sister chromatids separate during anaphase Meiosis o Prophase homologous chromosomes come together in pairs crossing over occurs o Metaphase pairs align at middle of cell o Anaphase Telophase homologous chromosomes separate during anaphase one Sister chromatids remain together sister chromatids separate during anaphase two 22 How do the chromosomes line up in Metaphase One of Meiosis Metaphase Two Align randomly homolog pairs one on either side of plate Lined up 23 How do the chromosomes divide in Anaphase One of meiosis Anaphase Two Move to opposite pole consists of sister chromatids Divide become independent chromatids 24 How many times does the DNA replicate in Meiosis Twice 25 How many cells do you start with and end for mitosis and meiosis Meiosis Start with one cell with a full number of chromosomes and end with four cells each with half the number of chromosomes as the first cell Mitosis Start with one cell with a full number of chromosomes and end with two cells with the same number of chromosomes 26 What