Biology 171 Transmission of Genetic Material Pea plants have many contrasting traits that made them a good model organism for early plant breeders and geneticists like Mendel We will examine two traits seed color and plant height in this PQ set The gene for plant height gene H has two alleles H and h and is located on chromosome 4 The gene for seed color gene G has two alleles G and g and is located on chromosome 5 1 Do chromosomes 4 and 5 assort independently during mitosis 2 Consider a cell in the leaf of a pea plant One chromosome 4 has an H allele and one No chromosome 4 has an h allele One chromosome 5 has a G allele and one chromosome 5 has a g allele a Draw a diagram of this leaf cell with chromosomes 4 and 5 Mark the alleles for seed color and plant height Draw this cell PRIOR to S phase of the cell cycle Although chromosomes are not condensed prior to mitosis you can draw them as lines for simplicity b Draw a diagram of this leaf cell with chromosomes 4 and 5 Mark the alleles for seed color and plant height Draw this cell during late Prophase of mitosis c Draw a diagram of this leaf cell with chromosome 4 and 5 Mark the alleles for seed color and plant height Draw this cell during METAPHASE of mitosis d Assuming no errors during mitosis how many different types of daughter cells are possible at the end of cytokinesis of this leaf cell Focus on the genes and chromosomes described above I type e How many of chromosome 4 will each daughter cell have after mitosis and cytokinesis 2 of chromosome 4 1 pair f What will the genotype s of the daughter cells be after mitosis and cytokinesis identical to parentcell g Will the daughter cells produced after mitosis and cytokinesis be haploid diploid or something else diploid h Will this leaf cell show the G and H phenotypes Why or why not S 1 H to n4 pg A y poly hor Sjlgiye No G Seed color and H plants height neither orwhich affectthe leaf 3 Consider a germ cell in the ovary of a pea flower One chromosome 4 has an H allele and one chromosome 4 has an h allele One chromosome 5 has a G allele and one chromosome 5 has a g allele a Draw a diagram of this germ cell with chromosome 4 and 5 Mark the alleles for seed color and plant height Draw this cell PRIOR to S phase of the cell cycle Although chromosomes are not condensed prior to mitosis and meiosis you can draw them as simple lines for simplicity b Draw a diagram of this germ cell with chromosome 4 and 5 Mark the alleles for seed color and plant height Draw this cell during Prophase of meiosis I For this exercise you can ignore crossing over c Draw a diagram of this leaf cell with chromosome 4 and 5 Mark the alleles for seed color and plant height Draw this cell during METAPHASE of meiosis I Ignore crossing over i How many ways can the homologous pairs line up in the center of the cell 8 I g runforstate Stall i ratIpo 99 d hh focusing on chromosomes 4 5 2 dominantvs recessive or wI dominantorItype and recessive ofother d Assume that the homologous pairs line up such that one daughter cell of meiosis glof iHa I receives H g while the other daughter cell of meiosis I receives h G i Are the sister chromatids still together and attached at the centromere when they move into meiosis II Yes ii Draw the 2 cells in metaphase of meiosis II iii Given this scenario what is are the genotype s of the daughter cells of meiosis II A 9 and h 6 iv Are the daughter cells produced at the completion of meiosis II haploid or diploid or something else Haploid v Will the daughter cells of meiosis II become germ cells somatic cells or gametes 4 Which phase s of the cell cycle phase s of mitosis or phase s of meiosis is this germ cell in Note that there are other chromosomes but we are only focusing on chromosomes 4 5 Be as specific as possible in your answer 5 5 4 4 Meiosis II MetaphaseII Chaploid 5 Which phase s of the cell cycle mitosis or meiosis is this cell in Note that there are other chromosomes but we are only focusing on chromosomes 4 5 Cell cycle before S phase 6 Which phase s of the cell cycle mitosis or meiosis is this cell in Note that there are other chromosomes but we are only focusing on chromosomes 4 5 Mitosis Metaphase diploid 5 4 4 5 5 5 4 4 5 5 4 4 7 A student is trying to draw the daughter cells of meiosis II and draws this figure What errors did this student make 5 5 4 4 The sister chromatics should be separated t each cell shared only have I oreach chromosome Thinking About BRCA Mutations Consider Adam and Leah in VISUAL SYNTHESIS FIG 19 26 GENETIC VARIATION AND INHERITANCE pages 418 and 419 in How Life Works 8 Leah has one maternal chromosome 17 and one paternal chromosome 17 as well as one maternal chromosome 13 and one paternal chromosome 13 Why does Leah have a maternal and paternal chromosome for each homologous pair Where does the maternal chromosome come from Where does the paternal chromosomes come from Refer to the meiosis that happened in Leah s parents cells 9 Imagine that Leah s chromosome 17s and chromosome 13s independently assort Maternal Mother Paternal Father during meiosis in one of her germ cells a Draw a diagram of metaphase I of meiosis Draw only chromosomes 13 17 17logis is lot fat is b Label the chromosomes as maternal and paternal Show what is meant by independent assortment of the maternal and paternal chromosomes by drawing alternative chromosome alignments in metaphase of meiosis I You will need 2 diagrams to answer this question c How many gamete genotypes can Leah make considering chromosomes 13 17 and the BRCA 1 and BRCA 2 genes B 10 One only 1 germ cell of the many germ cells in one of Adam s testes has a spontaneous mutation such that only that germ cell now has one BRCA2 allele and one BRCA2 allele Assume that Adam s germ cell with the BRCA2 BRCA2 genotype undergoes meiosis and produces sperm If only this one germ cell undergoes meiosis not all the germ cells what is the maximum number of genotypes of gametes produced from this one germ cell is Not all is is of fat pa 2 genotypes In How Life Works VISUAL SYNTHESIS FIG 19 26 GENETIC VARIATION AND INHERITANCE Consider Ben and Sarah and focus only on chromosome 17 The following questions exercise focuses on the BRCA1 mutation on chromosome 17 In your work we suggest show the BRCA1 mutations as 1 1 minus and the allele without this mutation …