Cell Reproduction Page #1 Warm Up Where are your genes located?

http://people.na.infn.it/~nicodem/research/cell_genes.jpg

FROM DNA TO CHROMOSOMES DURING MOST OF THE CELL’S LIFE, DNA FORMS A TANGLED MASS CALLED CHROMATIN. CHROMATIN LOOKS LIKE A PLATE OF SPAGHETTI. RIGHT BEFORE A CELL DIVIDES, THE CHROMATIN FORMS INTO CHROMOSOMES (X-SHAPED).

CHROMATIN CHROMOSOMES MOST OF THE TIME ONCE IN A WHILE

Draw this in your notes

Cell Division Chromosomes = Tightly coiled, rod-shaped DNA Chromosomes are made of chromatin Human body produces 2 trillion cells per day & 25 million per second Cells are formed by cell division of older cells When a cell divides, DNA is first copied & then distributed Each cell ends up with a complete set of DNA

Chromosome Number Each human somatic cell has 2 copies of 23 different chromosomes Total 46 Somatic = any cell that is NOT a sex cell (also called body cells or autosomes)

Sets of Chromosomes Each pair is made up of 2 homologous chromosomes Homologous chromosomes = chromosomes that are similar in size, shape, & genetic content Each homologue comes from one of the parents One from mom One from dad

Cells Can Be Diploid or Haploid Diploid = a cell that contains 2 sets of chromosomes (2n) Haploid (monoploid) = a cell that contains only 1 set of chromosomes (1n or n)

Chromosomes Determine Your Gender Humans have 23 pairs of chromosomes 22 pairs are autosomes (chromosomes NOT directly involved in determining sex) 1 pair are sex chromosomes (contain genes that WILL determine the sex) X & Y chromosomes

So-Which parent determines the sex of the baby? X & Y Chromosomes Male = XY Female = XX Male (dad) can donate an X or a Y to offspring Female (mom) can ONLY donate an X So-Which parent determines the sex of the baby?

MALE XY

Gametes Gametes are reproductive cells Males = sperm (n = 23) Female = egg (n = 23) Combine in fertilization to make a: Zygote (2n = 46)

Haploid VS Diploid Page #2

“Understanding the concepts of Haploid and Diploid”

Introducing Vocabulary Diploid= DIH – ployd Haploid= HA – ployd

Haploid and Diploid Let’s take a look at the terms first…. Diploid= Di Ploid “Di” means “two”

Haploid and Diploid Let’s take a look at the terms first…. Haploid= Ha Ploid think “HAlf” haploid is half of diploid.

Review “Diploid” means Haploid and Diploid Review “Diploid” means Half Two

Review “Haploid” means Haploid and Diploid Review “Haploid” means Half Two

GOOD JOB !!! You’re on the way !!!

Introducing Vocabulary Gamete= GA - meat Somatic= So-MA-tik

Haploid and Diploid A “Gamete” is a generic term for a “sex cell”. An example would be a sperm or an egg.

Gametes are Haploid in chromosome number. Haploid and Diploid Gametes are Haploid in chromosome number.

Haploid and Diploid The number of chromosomes that a gamete would contain would be described as______ Haploid Diploid

“Somatic cells” refers to every other cell in the body except gametes. Haploid and Diploid “Somatic cells” refers to every other cell in the body except gametes.

Review Sperm or Egg = Gametes All Other cells = Somatic Cells Haploid and Diploid Review Sperm or Egg = Gametes All Other cells = Somatic Cells

Gamete or Somatic Cell ? A Liver Cell Haploid and Diploid Gamete or Somatic Cell ? A Liver Cell Gamete Somatic Cell

Gamete or Somatic Cell ? A Sperm Cell Haploid and Diploid Gamete or Somatic Cell ? A Sperm Cell Gamete Somatic Cell

Gamete or Somatic Cell ? A Brain Cell Haploid and Diploid Gamete or Somatic Cell ? A Brain Cell Gamete Somatic Cell

Gamete or Somatic Cell ? A Lung Cell Haploid and Diploid Gamete or Somatic Cell ? A Lung Cell Gamete Somatic Cell

Gamete or Somatic Cell ? An Egg Haploid and Diploid Gamete or Somatic Cell ? An Egg Gamete Somatic Cell

Gamete or Somatic Cell ? A Skin Cell Haploid and Diploid Gamete or Somatic Cell ? A Skin Cell Gamete Somatic Cell

Keep Going !!! HAlf way There !!!

Somatic Cells are Diploid in chromosome number. Haploid and Diploid Somatic Cells are Diploid in chromosome number.

Haploid and Diploid The number of chromosomes that a somatic cell would contain would be described as______ Haploid Diploid

Review Gametes = haploid Somatic Cells = diploid Haploid and Diploid Review Gametes = haploid Somatic Cells = diploid

Mathematically Speaking if haploid=n, then diploid=2n Haploid and Diploid Mathematically Speaking if haploid=n, then diploid=2n

Haploid and Diploid Mathematically Speaking or… haploid is ½ of diploid or… diploid is 2x haploid

Haploid and Diploid Review Sperm or Egg = Gametes=Haploid=n All Other Cells = Somatic Cells=Diploid=2n

Haploid and Diploid Humans have 46 chromosomes in their somatic cells. These cells are ______ Haploid Diploid

Humans have 23 chromosomes in their gametes. These cells are ______ Haploid and Diploid Humans have 23 chromosomes in their gametes. These cells are ______ Haploid Diploid

If humans diploid number = 46, what is the haploid number? Haploid and Diploid If humans diploid number = 46, what is the haploid number? 23 92

If humans haploid number = 23, what is the diploid number? Haploid and Diploid If humans haploid number = 23, what is the diploid number? 46 92

If chimps diploid number = 48, what is the haploid number? Haploid and Diploid If chimps diploid number = 48, what is the haploid number? 24 96

If chimps haploid number = 24, what is the diploid number? Haploid and Diploid If chimps haploid number = 24, what is the diploid number? 48 96

Haploid and Diploid Review Again Sperm or Egg = Gametes=Haploid= n All Other Cells = Somatic Cells=Diploid= 2n

If humans diploid number = 46, How many chromosomes in a liver cell ? Haploid and Diploid If humans diploid number = 46, How many chromosomes in a liver cell ? 23 46

If humans diploid number = 46, How many chromosomes in a sperm cell ? Haploid and Diploid If humans diploid number = 46, How many chromosomes in a sperm cell ? 23 46

If humans diploid number = 46, How many chromosomes in a brain cell ? Haploid and Diploid If humans diploid number = 46, How many chromosomes in a brain cell ? 23 46

If humans diploid number = 46, How many chromosomes in a lung cell ? Haploid and Diploid If humans diploid number = 46, How many chromosomes in a lung cell ? 23 46

If humans diploid number = 46, How many chromosomes in an egg cell ? Haploid and Diploid If humans diploid number = 46, How many chromosomes in an egg cell ? 23 46

If humans diploid number = 46, How many chromosomes in a skin cell ? Haploid and Diploid If humans diploid number = 46, How many chromosomes in a skin cell ? 23 46

Up so far !!! ALMOST THERE !!!

Haploid and Diploid Review Last Round Sperm or Egg = Gametes=Haploid= n All Other Cells = Somatic Cells=Diploid= 2n

Haploid and Diploid If chimp’s haploid number = 24, How many chromosomes in a chimp’s liver cell ? 24 48

Haploid and Diploid If chimp’s haploid number = 24, How many chromosomes in a chimp’s egg cell ? 24 48

Haploid and Diploid If Horse’s diploid number = 64, How many chromosomes in a Horse’s liver cell ? 32 64

Haploid and Diploid If Alligators’s diploid number = 32, How many chromosomes in a Alligators’s liver cell ? 32 64

Haploid and Diploid If Dog’s diploid number = 78, How many chromosomes in a Dog’s sperm cell ? 39 78

http://www.goldiesroom.org/Shockwave_Pages/REG-15-haplodvdiploid.htm

Mitosis Animation http://www.goldiesroom.org/Shockwave_Pages/REG-14-tnm--celldivision.htm

Page #3 Karyotype Karyotype = a photo of the chromosomes in a dividing cell that shows the chromosomes arranged by size.

Karyotype cont’d Each of an individual’s 46 chromosomes has thousands of genes so the presence of all chromosomes is essential for normal functioning Humans who are missing a chromosome don’t survive Humans with more than two copies of a chromosome, called trisomy, may survive but will not develop properly.

What is wrong?

The Cell Cycle Repeating sequence of cell growth and division during an organism’s life 90% of cell life is spent in INTERPHASE Then it may go into MITOSIS & CYTOKINESIS

INTERPHASE (divided into mini-phases) G1(first growth) phase = Cell grows rapidly S (synthesis) phase = DNA copied G2 (2nd growth) phase = Nucleus prepares to divide

http://publications. nigms. nih. gov/insidethecell/ch4_interphase_big http://publications.nigms.nih.gov/insidethecell/ch4_interphase_big.html

AFTER INTERPHASE Mitosis Cytokinesis http://www.cellsalive.com/cell_cycle.htm

Having 3 copies of a chromosome is called a ______________ Mitosis and Meiosis WARM UP Females are X___ Males are X___ Having 3 copies of a chromosome is called a ______________

Mitosis and Meiosis Mitosis: -division of somatic (body) cells - results in two daughter cells that are identical Meiosis -division of gametes (sex cells)

Mitosis Interphase Prophase Metaphase Anaphase Telophase

The Cell Cycle is Carefully Controlled Key check points which feedback signals from the cell will delay the next step Controlled by proteins! Cell Growth CHECKPOINT (G1) – Start – Nerve/muscle cells stop here 2. DNA Synthesis CHECKPOINT (G2) – Enzymes 3. Mitosis CHECKPOINT – Back to G1 phase

Page #4 When Control is Lost -- Cancer Cancer = Cell growth is uncontrolled - does not respond to control mechanisms. Causes: Mutations that cause over-production of growth molecules – (accelerator) or by in-activating proteins that slow or stop the cell cycle (brakes) Tobacco and UV radiation linked to increased cancer risk.

Change in Chromosome Number Trisomy = humans with more than 2 copies of chromosomes – improper development Karyotype = a photo of the chromosomes in a dividing cell. Disjunction = when egg/sperm cells form – each chromosome and homologue separate – sometimes one or more chromosomes fail to separate - unequal distribution. Down Syndrome - 3 copies of chromosome 21- NONDISJUNCTION

Change in Chromosome Structure Mutation – A change in an organism’s chromosomal structure. Deletion = piece of chromosome breaks off completely – lacks of a set of genes – fatal Duplication = chromosome fragment attaches to its homologous chromosome –two copies of a gene set

Inversion = chromosome piece reattaches to original chromosome, but in reverse orientation. Translocation = chromosome piece reattaches to a nonhomologous chromosome.

Interphase Interesting things happen! Cell preparing to divide Genetic material doubles

Prophase Chromosome pair up! Chromosomes thicken and shorten -become visible -2 chromatids joined by a centromere Centrioles move to the opposite sides of the nucleus Nucleolus disappears

Metaphase Chromosomes meet in the middle! Chromosomes arrange at equator of cell Become attached to spindle fibres by centromeres Homologous chromosomes do not associate

Anaphase Chromosomes get pulled apart Spindle fibres contract pulling chromatids to the opposite poles of the cell

Telophase Now there are almost two! Chromosomes uncoil Spindle fibres disintegrate Centrioles replicate

Cytokinesis Cell splits

http://www.cellsalive.com/mitosis.htm

Metaphase

Telophase

Prophase

Anaphase

http://www.youtube.com/watch?v=HV5kPiDYC3M

Cell Reproduction Page #5 Warm Up List the stages of mitosis in order IPMAT

Meiosis Meiosis = Cell division that produces only haploid cells (half the number of chromosomes) Sex cells or gametes Spermatogenesis Oogenesis

Meiosis Occurs in Two Stages Meiosis I Meiosis II Follows the same order as MITOSIS, but it does it TWICE

Meiosis I Homologous chromosomes are separated into separate cells.

Interphase I Cell doubles its DNA and then doubles it again http://morgan.rutgers.edu/MorganWebFrames/Level1/Page7/meiosis1.html

Prophase I Chromosomes form Crossing over takes place http://morgan.rutgers.edu/MorganWebFrames/Level1/Page7/meiosis3.html

Crossing Over Exchanging corresponding segments of DNA Important because it gives a new combination of genes.

Crossing Over http://waynesword.palomar.edu/images/cross3.jpg

Metaphase I Chromosomes line up in the middle. http://morgan.rutgers.edu/MorganWebFrames/Level1/Page7/meiosis4.html

Anaphase I Chromosomes separate http://morgan.rutgers.edu/MorganWebFrames/Level1/Page7/meiosis5.html

Telophase I Cell begins to divide & 2 new cells form (cytokinesis) Each cell has chromosomes http://morgan.rutgers.edu/MorganWebFrames/Level1/Page7/Meiosis6.html

Meiosis II Chromatids of each chromosome are separated into separate cells http://botit.botany.wisc.edu/images/130/Meiosis/Lilium_microsporogenesis/Meiosis_II.html

Prophase II Chromosomes form in both cells http://morgan.rutgers.edu/MorganWebFrames/Level1/Page7/Meiosis7.html

Metaphase II Chromosomes line up along middle of cell http://morgan.rutgers.edu/MorganWebFrames/Level1/Page7/Meiosis8.html

Anaphase II Chromosomes separate and are pulled apart into chromatids http://morgan.rutgers.edu/MorganWebFrames/Level1/Page7/Meiosis9.html

http://www.scq.ubc.ca/filter/wp-content/uploads/2007/10/sister-chromatid.gif

Telophase II Chromatids gather at ends of cells Cytokinesis occurs – (cell splits apart) http://morgan.rutgers.edu/MorganWebFrames/Level1/Page7/Meiosis10.html

End Result of Meiosis & Cytokinesis 4 new cells each with half as much genetic info as the parent http://morgan.rutgers.edu/MorganWebFrames/Level1/Page7/Meiosis10.html

http://www.cellsalive.com/meiosis.htm

Spermatogenesis http://www.soc.ucsb.edu/sexinfo/images/12-06-spermatogenesis.gif

Oogenesis http://img.sparknotes.com/content/testprep/bookimgs/sat2/biology/0003/oogenesis.gif