Meiosis Flashcard Review How many daughter cells are produced during meiosis? 4 Mitosis produces two identical daughter cells Meiosis produces 4 different daughter cells What do meiosis and mitosis have in common? Replication occurs once. Chromosomes divide and carry DNA to new cells. Which reproductive process improves the genetic variability of the cells produced? Meiosis Replication only occurs once but the cells split twice. The resulting gamete unites with another gamete to produce genetic variety in the zygote. What is it called when DNA nucleotides are lost during meiosis? Deletion mutation. The lost nucleotides results in the wrong protein being made. A change in the sequence of DNA nucleotides is called A mutation What process reduces the number of chromosomes in preparation for sexual reproduction? Meiosis Reduces the number of human chromosomes from 46 to 23. What carries DNAs message to be translated by the ribosome? mRNA Transcription = DNA to mRNA Translation = mRNA to protein What causes mutations? What are their effects? They happen naturally or are caused by outside agents called mutagens. They may have no effect. They may have negative effects. They could have positive effects. They always increase genetic diversity. What cells are able to pass a mutation disease from mother to fetus? Gametes carry genetic information including changes caused by mutations. Diseases of somatic cells, like liver cancer, cannot be passed from generation to generation. What is abnormal about this karyotype? Deletion of the p arm in the 5 th pair of chromosomes. This causes Cri-du-Chat disease. Predict what would happen to the chromosome number of each generation if meiosis did not produce cells for sexual reproduction. Chromosome number would double with each new generation. Haploid cells are produced during Diploid cells are produced during Meiosis Mitosis What is the difference between meiosis 1 and meiosis 2? Meiosis 1 occurs first and produces identical, diploid cells. Meiosis 2 occurs last and produces 4 different, haploid sex cells. How would you determine if a karyotype was abnormal? There would be extra or missing chromosomes. There would be missing or added pieces attached to the chromosomes. Where does meiosis occur? Mitosis? The sex organs Normal, somatic body cells Which chromosome pair of a karyotype is the sex cells? The 23 rd pair. XX chromosomes appear the same size. Y chromosome is much smaller than the X. In a normal karyotype all of the chromosomes should be Paired. During meiosis, chromosomes exchange genes during Crossing over. This increases genetic variation. What is trisomy of the chromosomes? A nondisjuction mutaton causes the inheritance of three chromosomes instead of a pair. The homologous chromosomes should be paired. Chromosomal mutations are more serious than gene mutations because They involve whole or pieces of chromosomes which effects large amounts of DNA. Gene mutations involve individual strands of DNA which effect one trait. What determines the proteins that are made and thus the traits that appear in the phenotype of an organism? The arrangement of nucleotides in the DNA.