Ch 12 The Cell Cycle & Mitosis

1. Ch 12The Cell Cycle & Mitosis What did the brother cell say when the sister cell stepped on him? Mitosis.

2. PRE-EXISTING DIVISION REPRODUCTION WORN PARENT PART • Cells come from ________________ cells • This statement tells us that cells reproduce and the way they do this is through cell ________________ (p.218 Figure 12.1). • Roles in Life: • _________________ • Amoeba: divides and forms a duplicate • Plants: some can divide and form offspring • Sexual Reproduction: organisms develop from a single cell (zygote) • Renewal and Repair • Dying, ________, or torn cells. • Cell Cycle: life of a cell from the time it is formed from a dividing _________ cell until its own division into two cells. • Cell division is ________ of the cell cycle

3. IDENTICAL DNA GENOME 250,000 x BEFORE CHROMATIN PROTEINS CHROMOSOMES • Cell Division: results in genetically ________________ daughter cells • Organization of Genetic Material (______) • __________: the entire amount of genetic material (DNA) • Length of DNA is very large (2 m of DNA in human cells: __________ greater than a cell’s diameter). This DNA must be copied _________ division. • The reason DNA replication is not a problem is because DNA is packed into chromosomes made of ________________ (DNA wrapped around ___________) • Each species has a certain number of _________________ in each cell nucleus.

4. SOMATIC 46 GAMETES 23 • Two types of cells: • ___________ (body) cells: all cells that are not reproductive (sex) cells. • Ex: Humans have ___ chromosomes (2 sets of 23, one from each parent). • ____________ (sex/reproductive cells): sperm and egg cells • Ex. Human gametes have half as many chromosomes as somatic cells: one set of ______ chromosomes. http://www.genebase.com/learning/article/30

5. CONDENSES VISIBLE SISTER CENTROMERE http://en.wikipedia.org/wiki/File:Major_events_in_mitosis.svg • Distribution of Chromosomes During Cell Division • When not in division, each chromosome is in the form of chromatin, but ________________ (coils) to chromosomes after duplication so they are __________. • Each duplicated chromosome has two ___________ chromatids • Two chromatids, each containing an identical DNA molecule are attached at the ________________.

6. CHROMATIDS CHROMOSOMES IDENTICAL NUCLEUS CYTOPLASM BABY MOM DAD CYTOKINESIS NON-IDENTICAL GAMETES • In cell division, the two sister ________________separate into two nuclei, one at each end of the cell. • Once the sister chromatids separate, they are considered individual __________________. Each nucleus has a group of chromosomes ________________to the original. • Mitosis: division of the _____________ (chromosomes split into 2 identical sets) • Cytokinesis: division of the ________________ (division of the two nuclei into two cells) • Example: ______ (46 chromosomes): 23 chromosomes (______) + 23 chromosomes (______) • Mitosis and ________________produce the trillions of somatic cells that make up human bodies and continue to generate cells. • Meiosis: yields _________________ daughter cells that have only one set of chromosomes. Only occurs with __________. This will be covered in Ch. 13.

7. MITOTIC SHORTEST MITOSIS CYTOKINESIS • Phases of the Cell Cycle • ________________ (M) Phase (when division occurs)- ___________ part of the cell cycle that includes: • _________ • ______________. cell cycle animation http://scientopia.org/blogs/scicurious/2010/05/31/cell-cycle-p21-depression-and-neurogenesis-and-in-the-hippocampus/

8. 90 BETWEEN GROWS G1 ORGANELLE SYNTHESIS CHROMOSOMES G2 INTERPHASE PROMETAPHASE • Interphase (in ____________ cell divisions)- accounts for ____% of the cell cycle • Where the cell _________ and copies its chromosomes to prepare for division • Three Subphases: • ____ Phase (“first gap)- protein and ________________ (mitochondria and chloroplast) synthesis (double cell size) • S Phase (“________________”)-___________________ are duplicated (DNA synthesis only in S phase) • ___ Phase (second gap”)- continued growth • Sequence (remember): • ________________ (G1, S, G2), • M phase • mitosis: prophase, ___________________, metaphase, anaphase, telophase • cytokinesis

9. CYTOPLASM MICROTUBULES TUBULIN • Mitotic Spindle • Involved in many events of mitosis and begins to form in the ________________ during prophase. • Consists of fibers (__________________ and proteins). • The spindle microtubles lengthen by including more subunits of ________________. http://www2.estrellamountain.edu/faculty/farabee/biobk/biobookmito.html#Mitosis

10. CENTROSOME CENTRIOLES PLANTS INTERPHASE PROMETAPHASE OPPOSITE ASTER • Mitotic Spindle Assembly: • Starts at the ________________ • centrosome- a nonmembranous organelle that organizing the cell’s microtubules during the cell cycle • In animal cells, two ________________ • are located at the center of the centrosome but are not essential to cell division. Ex: ________ don’t have centrioles • ________________is when the centrosome replicates to form two which stay together near the nucleus. • The two move apart during prophase and __________________ as spindle microtubules grow from them. • At the end of prometaphase, the two centrosomes are on ____________ ends of the cell. An _________ which looks like a sun burst of microtubules from each centrosome.

11. KINETOCHORE CHROMATIDS OPPOSITE TUG OF WAR MIDWAY PLANE NONKINETOCHORE • Chromosomes • Each chromatid of a chromosome has a ________________-a structure of proteins that appear at specific sections of chromosomes at the centromere. • Kinetochores are where microtubules connect to pull sister ________________ apart • The centrosome’s two kinetochores face in ____________ directions. • During prometaphase, some of the spindle microtubules attach and are called kinetochore microtubules. • The next event is like a ________________ that ends in a draw: the chromosomes move and finally stop when the centromeres of all the duplicated chromosomes are on a plane __________ between the spindle’s two poles. This plane is the metaphase _______. • At this time there are some microtubules that are not attached to kinetochores but overlap and interact with other _______________________ microtubles.

13. INACTIVE ELONGATES OPPOSITE • Moving apart • Starts when the proteins holding the sister chromatids become ________________ allowing the sister chromatids to become separate chromosomes. • These chromatids will move toward opposite sides of the cell. • The region of overlap between the microtubules is reduced as ATP is used to push the microtubules apart. This ________________ the cell. • At the end of anaphase, duplicate groups of chromosomes arrive at ____________ ends of the now longer parent cell. • During telophase, nuclei reform and cytokinesis begins and the spindle disassembles.

14. http://royaleb.files.wordpress.com/2009/04/mitosis_phases1.jpghttp://royaleb.files.wordpress.com/2009/04/mitosis_phases1.jpg

15. PRESENT NUCLEOLI CENTRIOLES CHROMATIN • Summary of the Cell Cycle mitosis animation • Interphase • Nuclear envelope is ________________ • The nucleus has at least one ________________ • Two centrosomes have formed and will be next to each other (animal cells will have ______________). • In the nucleus, ________________ is seen http://humanbiorevision.tumblr.com/post/2845616247/interphase

16. CHROMOSOMES CENTROMERES ASTERS • Prophase • Chromatin has condensed into __________________. • Duplicated chromosomes appear as identical sister chromatids joined at _________________. • Nucleoli disappear. • Mitotic spindle forms as centrosomes move apart. as microtubules emerge from the centrosomes, _________ can also be seen. http://humanbiorevision.tumblr.com/post/2845688920/prophase

17. BREAKS CONDENSED EXTEND KINETOCHORE MOVE OPPOSITE http://www.stanford.edu/group/hopes/cgi-bin/drupal/node/3401 • Prometaphase • Nuclear envelope ___________ down. • Chromosomes become more ________________. • Microtubules from the mitotic spindle _________ even more. • Each sister chromatid has a ________________ located at the centromere. • Kinetochore microtubule: ________ chromosomes • Nonkinetochore microtubules interact with other nonkinetochore microtubules (from _____________ side).

18. OPPOSITE PLANE http://humanbiorevision.tumblr.com/post/2845819608/metaphase • Metaphase (longest stage of mitosis) • Centrosomes are at ________________ poles of cell • Chromosomes line up in the middle of the cell (metaphase __________) • The kinetochore of sister chromatids are connected to microtubules from the opposite pole.

19. COHESION SHORTEN LENGTHEN EQUAL • Anaphase- shortest stage of mitosis • ____________ protein cleaved allowing sister chromatids to move apart allowing each to become a separate chromosome. • The two chromosomes move toward opposite ends of the cell as kinetochore microtubules ___________. • The nonkinetochore microtubules ____________ which elongate the cell • At the end, the two ends of the cell have an _________ amount of complete chromosomes. http://humanbiorevision.tumblr.com/post/2845909550/anaphase

20. TWO FRAGMENTS NUCLEOLI CHROMATIN IDENTICAL • Telophase • ______ nuclei form in the cell. • Nuclear envelopes form from parent cell’s nuclear envelope ____________. • ________________ reappear • Chromosomes become less condense (________________) • Mitosis is complete (2 complete, ___________ nuclei) http://humanbiorevision.tumblr.com/post/2845943979/telophase

21. TELOPHASE DAUGHTER • Cytokinesis • Division of cytoplasm usually starts in late _____________. • Two ________________ cells appear shortly after mitosis ends. • Animal cells form a cleavage ___________ which pinches the cell (cytoplasm) in two. • Plant cells form a ________________ which divides the cell (cytoplasm) in two. FURROW PLATE

22. http://www.tutorvista.com/biology/cytokinesis-pictures http://www.monteweston.com/Biology/Preeti.html • Cytokinesis in Detail • Cleavage Furrow (animals) • First sign is a shallow groove in the cell surface near the old metaphase plate. • It deepens until the parent cell is pinched in two producing two separated cells with their own organelles, etc.

23. VESICLES FUSES WALL • Cell Plate (plants) • Cell wall materials carried in the ___________ collect in the cell plate as it grows. The cell plate grows until its membrane _______ with the plasma membrane along the perimeter of the cell. • Two daughter cells result, each with its own plasma membrane and cell ______. http://www.phschool.com/science/biology_place/biocoach/mitosisisg/cytokin.html

24. ASEXUAL MITOSIS • Binary Fission • ________________ reproduction of single-celled eukaryotes, such as the amoeba includes mitosis and occurs by a type of cell division called binary fission, meaning "division in half.' • Prokaryotes (bacteria and archaea) also reproduce by binary fission, but the prokaryotic process does not involve ________________.

26. Evolution of Mitosis Hypothesis: mitosis had its origins in ________________ prokaryotic mechanisms of cell reproduction. Support: Some of the proteins involved in bacterial binary fission are related to eukaryotic ________________ that function in mitosis. As eukaryotes evolved, with larger genomes and nuclear envelopes, binary fission, seen today in bacteria, somehow led to ________________. Possible hypothesis for the stepwise evolution of mitosis. Figure 12.12 p.237 SIMPLER PROTEINS MITOSIS

27. What controls the cell cycle? Cell Cycle is controlled by specific ________________ molecules in the cytoplasm. Experiment: Two cells in different phases of the cell cycle were fused to form a single cell with two nuclei. If one of the original cells was in the S phase and the other was in G1, the G1 nucleus immediately entered the ___ phase Similarly, if a cell undergoing mitosis (M phase) was fused with another cell in any stage of its cell cycle, even G1, the second nucleus immediately entered ___________, with condensation of the chromatin and formation of a mitotic spindle SIGNALING S MITOSIS

28. Cell Cycle Control System Definition: a ________________ operating set of molecules in the cell that both triggers and coordinates key events in the cell cycle. Checkpoint- a control point where stop and go-ahead signals regulate the cycle. Animal cells usually have built-in stop signals that ________ the cell cycle at checkpoints until overridden by go-ahead signals. Signals report whether cellular processes that should have occurred have occurred and whether or not the cell cycle should ________________. Three major ________________ are found in the G1,G2, and M phases CYCLICALLY PAUSE PROCEED CHECKPOINTS

29. For many cells, the G1 checkpoint ("_______________ point") in mammalian cells, seems to be the most important: if a cell receives a go-ahead signal at the G1 checkpoint, it will usually ________ the cell cycle. If a go-ahead signal is not given, it will exit the cycle, switching into a ________________ state called the G0 (G ZERO) phase. (most cells in G0 phase). Example: Think a ____________ machine. Timing device: the cell cycle control system works on its own, according to a built-in clock. Internal and External ______________: Washers have an internal sensor that detects when the water is present and external adjustment such as pressing the start button. RESTRICTION FINISH NONDIVIDING WASHING REGULATION

30. ______________________ molecules: Protein Kinases and Cyclins Protein kinases- enzymes that activate or inactivate other proteins by _______________________ them Protein kinases- give the go-ahead signals at the G1 and G2 ________________. Many kinases that drive the cell cycle are present at a ________________ concentration in the growing cell, but are usually in an ___________ form. To be active, such a kinase must be attached to a ________________ (gets its name from its cyclically fluctuating concentration) CELL CYCLE CONTROL PHOSPHORYLATING CHECKPOINTS CONSTANT INACTIVE CYCLIN

31. Because of this requirement, these kinases are called cyclin-dependent kinases, or Cdks. The activity of a Cdk rises and falls with changes in the __________________ of its cyclin partner. Figure 12.16a shows the fluctuating activity of MPF, the cyclin-Cdk complex that was discovered first (in frog eggs). Peaks of MPF activity correspond to peaks of __________ concentration The cyc1in level rises during the S and G1 phases The initials MPF stand for "________________ -promoting factor”; but we can think of MPF as "M-phase-promoting factor” because it triggers cell’s passage through G2 checkpoint to M phase. CONCENTRATION CYCLIN MATURATION

32. Internal and External Signals _______________ Signal at the M phase checkpoint: __________________ In ______________, sister chromatids do not _______________ until all the chromosomes are properly attached to the spindle at the metaphase plate. It is the __________________ that send a signal that delays anaphase. When the kinetochores of all chromosomes are ______________, the sister chromatids can _____________. This allows daughter cells to have an ____________ amount of chromosomes. INTERNAL ANAPHASE ANAPHASE SEPARATE KINETOCHORES ATTACHED SEPARATE EQUAL

33. _______________ Factors that limit cell division Cells will fail to _____________ if an essential nutrient is left out of the culture. ______________ factors are needed for division. Growth factors are ______________ released by cells that stimulate cell division. Platelet-derived growth factor (______) p. 231 Figure 12.17 Made by blood cells called ________________. Demonstrates that PDGF is _____________ for the division of fibroblasts in culture. PDGF sends a signal that allows cells to pass ______ checkpoint to divide. EXTERNAL DIVIDE GROWTH PROTEINS PDGF PLATELETS REQUIRED G1

34. Density-dependent _____________ (effect of an external physical factor) Phenomena where crowded cells stop ____________ (p. 232: Figure 12.18a) Cells normally divide until they form a __________ layer on the surface of the container then they ________ dividing. If cells are __________, the cells around the empty space __________ until the space is filled. It was first thought that ____________ contact sent a signal to stop division but growth factors has a larger effect: When a cell population reaches a certain ____________, the nutrients available are insufficient so cell division stops. Anchorage dependence- to divide, cells must be ____________ to a (stable) surface such as a dish or extracellular matrix of a tissue. INHIBITION DIVIDING SINGLE STOP REMOVED DIVIDE PHYSICAL DENSITY ATTACHED

35. Loss of Cell Cycle Control in Cancer Cells Cancer cells do _______ follow the regulations/signals like normal cells and divide excessively and invade other tissues. Cancer cells lack ____________________________________, anchorage dependence, and do not stop dividing when growth factors are depleted. Example: p. 233 Figure 12.19 Hypotheses why: Cancer cells do not need growth factors. Cancer cells make their own growth factors. Cancer cells can display growth factor’s signal despite the lack of growth factors. Abnormal cell cycle control system. (more in Ch. 19) NOT DENSITY-DEPENDENT INHIBITION

36. Other differences between normal and cancer cells When/if cancer cells stop division, it is ____________ instead of at checkpoints. Cancer cells can divide _______________ if they have a continual supply of nutrients. Ex. HeLa cells RANDOM INDEFINITELY

37. Behavior of Cancer Cells Transformation (change in DNA) occurs when a single cell in a tissue ______________ from a normal cell to a cancer cell. The __________ system can destroy it but if the cancer cell avoids destruction, it can continue to grow and form a tumor- a mass of abnormal cells within a “normal” tissue. ________________ tumor- abnormal cells remain at the original site No serious problems and can be removed by surgery. _______________ tumor- abnormal cells invasive enough to impair the functions of one or more organs. Someone with a malignant tumor is said to have cancer. TRANSFORMS IMMUNE BENIGN MALIGNANT

38. Malignant tumors: may have unusual numbers of ___________________ ________________ may be disabled- may not function in a constructive way May lose or destroy attachments to neighboring cells and the ECM to spread into nearby tissues. Can also secrete molecules that cause ___________________to grow toward the tumor. Tumor cells can separate and enter the blood vessels to travel to other parts of the body where they can form a new tumor. ________________- spread of cancer cells to locations away form original site. CHROMOSOMES METABOLISM BLOOD VESSELS METASTASIS

40. Treatment: Localized tumors may be treated with high-energy _________________ Radiation damages _______ in cancer cells much more than normal cells because cancer cells have lost the ability to repair such damage. ____________________- drugs toxic to actively dividing cells are given through the circulatory system to treat suspected metastatic tumors. Chemotherapeutic drugs interfere with steps of the cell cycle Example: Taxol freezes the mitotic spindle which stops actively dividing cells from going beyond metaphase. Side effects of chemotherapy are from the drug’s effects on normal cells. Nausea is caused by effects on intestinal cells, hair loss on follicle cells, and increased susceptibility to infection on immune system cells. RADIATION DNA CHEMOTHERAPY

41. Chapter 13- Meiosis and Sexual Life Cycles

42. INHERITANCE • Introduction • Heredity or _________________- transmission of traits from one generation to the next • Heredity passes down inherited similarities and genetic _________________. • _________________- study of heredity and hereditary variation. VARIATION GENETICS

43. GENES SIMILARITIES • Acquisition of Genes • Parents pass down coded information in the form of _________ to their offspring. • It is the genes that account for family ______________ such as eye color, freckles, etc. • Our genes program the specific __________ that emerge as we develop from fertilized eggs into adults. • In order to pass down hereditary traits, ________ must first be replicated. • In animals, ___________ (reproductive cells) are what pass genes from one generation to the next. • _________________: the uniting of male and female gametes (sperm and egg) which passes genes of both parents to the ____________. TRAITS DNA GAMETES FERTILIZATION OFFSPRING

44. CHROMOSOMES MANY LOCUS • _________________ consist of a single long DNA coiled with proteins. • __________ genes are located on a chromosome • ________: a gene’s specific location along the chromosome • Asexual Reproduction (p. 239 fig 13.2) • Definition: organisms produce offspring that are _________________to them (all the genes are passed). • Offspring are all identical: ___________. • Example: Hydra- can reproduce by budding (_________) IDENTICAL CLONES MITOSIS

45. COMBINATIONS • Sexual Reproduction • Definition: two parents give rise to offspring that have unique _________________ of genes inherited from the parents. • Offspring are genetically _________________from siblings and parents. • Allows genetic _____________. • Why different than asexual reproduction? • Behavior of _________________ during the gamete life cycle. DIFFERENT VARIATION CHROMOSOMES

46. BIRTH KARYOTYPE • Sexual Life Cycles • Life cycle- generation to generation occurrences in the reproductive history of an organism from _______________ to having its own offspring. • _________________- display of 46 human chromosomes from a single cell in mitosis. • Chromosomes are arranged in __________, according to size and structure. • ___________________ chromosomes (_________________): the two chromosomes have the same length, centromere position, staining pattern. • Both carry genes that control the same ____________. • Ex. Eye color gene exists at the __________ locus as on the other chromosome (genes may not be identical i.e. freckles) • Karyotyping can be done using cells collected by chorionic villus (placental tissue) sampling or ____________________ for pre-natal diagnosis of chromosome _________________. • Used to _______ for chromosome abnormalities and genetic disorders • Controversy…. PAIRS HOMOLOGOUS SIMILAR TRAIT SAME AMNIOCENTESIS ABNORMALITIES TEST

47. SEX AUTOSOMES • Sex chromosomes- X and Y chromosomes determine an individual’s _____. All other chromosomes are called _________________. • XX- female XY-male • X is much ________ than Y. Only small parts of X and Y are ________________. Most genes on the X do not have _________________ on the Y and vice versa. LARGER HOMOLOGOUS COUNTERPARTS

48. PARENT SINGLE DIPLOID • Why do we have homologous pairs of chromosomes? • We inherit one from each ____________. Total: 23 (mom) + 23 (dad) • n- the number of chromosomes in a __________ set. • _________ cell- any cell with two chromosome sets and also a diploid number of chromosomes (2n) • Example: Humans- Diploid number is 46 and _____= 46 • Haploid cell- any cell with a _________ chromosome set and also a haploid number of chromosomes (n) • Example: Humans- Haploid number is 23 and n = 23 • The 23 consist of 22 _________________ and a single sex chromosome. • Unfertilized egg cell (________) contains an X chromosome while sperm cell can contain _________________ chromosome. • Figure 13.4 2n SINGLE AUTOSOMES OVUM X OR Y

49. FUSES • Human Life Cycle • Starts when a haploid sperm cell from the father _______ with the haploid ovum cell from the mother. • The fusing of the gametes ends in fertilization, the fusion of their __________. • The fertilized egg, _______________, is diploid because of the fusion of the two ______________ sets. • As the zygote develops into a mature adult, ____________ generates all the somatic cells by passing both chromosome sets and all the genes. NUCLEI ZYGOTE HAPLOID MITOSIS

50. GAMETES MITOSIS PRODUCES IDENTICAL CELLS • The only human cells not produced by mitosis are the __________ which generate in the gonads (ovaries in females and testes in males). • Why not divide by mitosis • ____________________________________________ • Gametes use ____________: a type of cell division which _________________ the number of sets of chromosomes from two to ______ in gametes to prepare for the doubling during fertilization. (_____________ division from diploid to haploid) MEIOSIS HALVES ONE REDUCTION