Copyright © by Holt, Rinehart and Winston. All rights reserved. When are sister chromatids formed? When are they separated? When are homologous pairs separated? Question of the Day 3-7

Copyright © by Holt, Rinehart and Winston. All rights reserved. 1. What is cancer? 2. What causes cancer? Question of the Day 3-8

Copyright © by Holt, Rinehart and Winston. All rights reserved. How Cancer Grows Quiz make ups Read Section 8.3 in the Owl Book and answer #s 1-6 on page 156 Today 3-7

Copyright © by Holt, Rinehart and Winston. All rights reserved. What is a haploid cell (there are multiple correct answers)? Question of the Day 3-9

Copyright © by Holt, Rinehart and Winston. All rights reserved. Control of Cell Division Cell division in eukaryotes is controlled by many proteins. Cell division in eukaryotes is controlled by many proteins. Contact Inhibition = when normal cells come in contact with one another, growth stops Contact Inhibition = when normal cells come in contact with one another, growth stops

Copyright © by Holt, Rinehart and Winston. All rights reserved. Cancer may result if cells do not respond to control mechanisms. Cancer may result if cells do not respond to control mechanisms. Contact Inhibition - –When normal cells come in contact with one another, growth stops –Cancer cells do not stop dividing when they come in contact. Cancer

Copyright © by Holt, Rinehart and Winston. All rights reserved. Cancer = uncontrolled cell growth = uncontrolled cell growth causes = mutated DNA (genetic or environmental) causes = mutated DNA (genetic or environmental)

Copyright © by Holt, Rinehart and Winston. All rights reserved. What is contact inhibition (notes yesterday)? Question of the Day 3-10

Copyright © by Holt, Rinehart and Winston. All rights reserved. PEROIDS 1 & 2: Monday March 14, Tuesday March 15, and Wednesday March 16 class is in mod # 1. Bring study hall type work / reading for second half of class IMPORTANT ANNOUNCEMENT

Copyright © by Holt, Rinehart and Winston. All rights reserved. Meiosis

Mitosis Review Genetically – how similar are the daughter cells in mitosis? Genetically – how similar are the daughter cells in mitosis? –They are identical When is the DNA copied for the new cell? When is the DNA copied for the new cell? –S phase of interphase What are two things make up chromosomes? What are two things make up chromosomes? –DNA and histones (protein) What is the middle part of the chromosome? What is the middle part of the chromosome? –Centromere What gets separated during mitosis? What gets separated during mitosis? –Sister chromatids NOT homologous pairs

Copyright © by Holt, Rinehart and Winston. All rights reserved. Meiosis Objectives Compare the end products of meiosis with those of mitosis. Compare the end products of meiosis with those of mitosis. Summarize the events of meiosis I. Summarize the events of meiosis I. Explain crossing-over and how it contributes to the production of unique individuals. Explain crossing-over and how it contributes to the production of unique individuals. Summarize the events of meiosis II. Summarize the events of meiosis II. Compare spermatogenesis and oogenesis. Compare spermatogenesis and oogenesis. Define sexual reproduction. Define sexual reproduction.

Copyright © by Holt, Rinehart and Winston. All rights reserved. What does DIPLOID mean? What does DIPLOID mean? –Cells having 2 homologous copies of each chromosome (2n - homologous pairs) What does HAPLOID mean? What does HAPLOID mean? –Number of chromosomes in a gamete (1n) or half the total number of chromosomes What is are sister chromatids? What is are sister chromatids? –Identical copies of the same chromosome Important vocab. review

Copyright © by Holt, Rinehart and Winston. All rights reserved. What is are sister chromatids? What is are sister chromatids? –Identical copies of the same chromosome When does the cell produce the copy of the chromatid? When does the cell produce the copy of the chromatid? –S phase of interphase Important vocab. review

Copyright © by Holt, Rinehart and Winston. All rights reserved. What are homologous chromosomes? What are homologous chromosomes? –Chromosomes that carry genes for same traits (though variation of the trait may differ) –Allele – variation of a trait Trait = flower color Trait = flower color Alleles = genes for either white or purple flowers Alleles = genes for either white or purple flowers Important vocab. review

Copyright © by Holt, Rinehart and Winston. All rights reserved. Formation of Haploid Cells Meiosis – a process of division that reduces the number of chromosomes in new cells to half the number in the original cell. Meiosis – a process of division that reduces the number of chromosomes in new cells to half the number in the original cell. 2n cells  1n cells 2n cells  1n cells Occurs in our sex cells (makes sperm and eggs) Occurs in our sex cells (makes sperm and eggs)

Copyright © by Holt, Rinehart and Winston. All rights reserved. Formation of Haploid Cells Four new haploid cells result (gametes) Four new haploid cells result (gametes) Meiosis is broken down into Meiosis I and Meiosis II. Meiosis is broken down into Meiosis I and Meiosis II.

Copyright © by Holt, Rinehart and Winston. All rights reserved. Poster Contest 3-8 Topics: The S-phase of Interphase Prophase Metaphase Anaphase Telophase Cytokinesis The chromosome MAKE SURE YOU GET A CHECKLIST FOR YOUR TOPIC!!! Creativity Slogan / Title Aesthetically pleasing Accurately descriptive and understandable

Copyright © by Holt, Rinehart and Winston. All rights reserved.

During meiosis… Synapsis – Synapsis – –Pairing of homologous chromosomes during prophase I –This did not occur in mitosis Tetrad – Tetrad – –Two pairs of homologous chromosomes

Copyright © by Holt, Rinehart and Winston. All rights reserved. Formation of Haploid Cells Crossing-over – Crossing-over – when portions of homologous chromosomes exchange genetic material when portions of homologous chromosomes exchange genetic material Occurs during prophase I and results in genetic recombination. Occurs during prophase I and results in genetic recombination. Genetic recombination – Genetic recombination – Regrouping of genes in an offspring that results in a genetic makeup that is different from the parents Regrouping of genes in an offspring that results in a genetic makeup that is different from the parents

Copyright © by Holt, Rinehart and Winston. All rights reserved. Crossing Over

Copyright © by Holt, Rinehart and Winston. All rights reserved ATB What is contact inhibition? What can happen when it fails? What is contact inhibition? What can happen when it fails? Objectives: Objectives: –Describe ways in which cancer can form –Describe how cancer moves around the body –Laptops – use to answer the worksheet questions dealing with cancer.

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ATB2-22 Do we have an even # of chromosomes or and odd #. Explain your reasoning. Do we have an even # of chromosomes or and odd #. Explain your reasoning. Today: Today: –Use laptops or books to answer the questions on your worksheet –Make sure you answer them accurately – they will be graded and are your notes Objectives: Objectives: –Describe the structure of a chromosome. –Identify the differences in structure between prokaryotic chromosomes and eukaryotic chromosomes. –Compare the numbers of chromosomes in different species.

Copyright © by Holt, Rinehart and Winston. All rights reserved. 2-23ATB What is the function of histones? What is the function of histones? Take out research sheet from yesterday Take out research sheet from yesterday Today: Today: –Complete the first page of the worksheet packet –Go over the paper from yesterday Objectives: Objectives: –Describe the structure of a chromosome –Identify the differences in structure between prokaryotic chromosomes and eukaryotic chromosomes. –Compare the numbers of chromosomes in different species. –Explain the differences between sex chromosomes and autosomes. –Distinguish between diploid and haploid cells.

Copyright © by Holt, Rinehart and Winston. All rights reserved. 3-1 ATB Describe the genetic material of a prokaryotic cell. Describe the genetic material of a prokaryotic cell. WS Packet pages 3 & 4 WS Packet pages 3 & 4 Today: Today: –Compare chromosome numbers –Compare / contrast autosomes and sex chromosomes –Describe a karyotype

Copyright © by Holt, Rinehart and Winston. All rights reserved. 3-3 ATB What are three factors you can use to line up homologous chromosomes What are three factors you can use to line up homologous chromosomes OBJECTIVES: OBJECTIVES: –Quiz Friday –Karyotyping activity due Friday Omit #3 and & #4 on page 30 and #1 and #2 under the “Extensions” on page 30 Omit #3 and & #4 on page 30 and #1 and #2 under the “Extensions” on page 30 –Complete your karyotypes (you have 15 minutes) –Describe diploid and haploid cells

Copyright © by Holt, Rinehart and Winston. All rights reserved. Section 2 Cell Division Chapter 8 Objectives Describe the events of cell division in prokaryotes. Describe the events of cell division in prokaryotes. Name the two parts of the cell that are equally divided during cell division in eukaryotes. Name the two parts of the cell that are equally divided during cell division in eukaryotes. Summarize the events of interphase. Summarize the events of interphase. Describe the stages of mitosis. Describe the stages of mitosis. Compare cytokinesis in animal cells with cytokinesis in plant cells. Compare cytokinesis in animal cells with cytokinesis in plant cells. Explain how cell division is controlled. Explain how cell division is controlled.

Copyright © by Holt, Rinehart and Winston. All rights reserved. 3-4 ATB What is the process by which prokaryotic cells replicate? What is the process by which prokaryotic cells replicate? Objectives: Objectives: –New Grades are up –Quiz / Karyotying Activity  Tomorrow –Describe the different steps of mitosis –Describe cell division

Copyright © by Holt, Rinehart and Winston. All rights reserved. 3-5 ATB What do cells have to do with their DNA before they replicate? What do cells have to do with their DNA before they replicate? OBJECTIVES: OBJECTIVES: –Karyotype activity due –QUIZ! –Take science survey –Discuss steps of cell division

Copyright © by Holt, Rinehart and Winston. All rights reserved. 3-8 ATB What is cell division? What is cell division? Objectives: Objectives: –Describe mitosis and it’s parts –Continue with online worksheet. –Go over the quiz

Copyright © by Holt, Rinehart and Winston. All rights reserved. 3-9 ATB What occurs in interphase? What occurs in interphase? Objectives: Objectives: –Worksheet Packet – do page 5 –Discuss the parts of cell cycle –Go over the quiz –Test on Thursday?

Copyright © by Holt, Rinehart and Winston. All rights reserved. ________________ Phase of mitosis = _________________ Phase of mitosis = _______________