740 likes | 755 Views
Observe and analyze the reproductive behaviors of unicellular organisms in this activity. Study the advantages and disadvantages of asexual and sexual reproduction. Learn about cellular reproduction and the cell cycle.
E N D
Reproduction Race • All of the organisms are unicellular. • The circles have to have one of each gender to reproduce . • The squares do not need a partner to reproduce. • Circles reproduce every 20 seconds. • Squares reproduce every 15 seconds. • The instructor will call out the time of when each organism type can reproduce. • Circles go in pairs (one of each gender) to “tag” an offspring (only one) • Squares go on their own and tag an offspring (only one). • When time is called again then you go again but keep watch of the temp. At certain temps. you die. • Watch what is going on because you will be asked to write about it when it is done.
Reproduction Race squares Can reproduce alone 15 seconds/generation circles Need a partner to reproduce 20 seconds/generation COLORS If you are teal green you are able to survive at the following temperature range If you are red you are able to survive at the following temperature range 25-75 degrees Celsius 50-100 degrees Celsius
On the left side of your interactive notebook, title the top: The Reproduction Race Write down everything you noticed going on during the activity. EX: none of the circles survived.
Two Types of Reproduction • Asexual Reproduction: one parent cell splits into 2 identical daughters cells • Sexual Reproduction: a father’s gamete cell (sperm) and a mother’s gamete cell (egg) fuse together to form a zygote
ON THE SAME LEFT SIDE PAPER WRITE YOUR ANSWER TO THE FOLLOWING STATEMENT WRITE SOME ADVANTAGES & DISADVANTAGES OF SEXUAL & ASEXUAL REPRODUCTION THAT YOU NOTICED IN THE REPRODUCTION RACE.
Advantages and Disadvantages of Sexual and Asexual Reproduction Advantages: Advantages: • Allows for genetic variation • Can result in better species • Does not require partner • Generally faster • Requires fewer steps Disadvantages: Disadvantages: • Does not allow for genetic variation • Requires partner • Requires special mechanisms
Why Do Cells Divide ?? • ENABLES ORGANISMS TO GROW, REPAIR & DEVELOP. • TO REPLACE DEAD CELLS • TO MAKE MORE OF THEMSELVES (SINGLE CELLED ORGANISMS) • TO CREATE GAMETES (sperm & egg cells) REGARDLESS OF WHY; ALL OF THE INFORMATION STORED IN THE DNA MUST BE PRESENT IN EACH OF THE RESULTING CELLS.
How Prokaryotes and Eukaryotes Reproduce • Prokaryotes- reproduce by binary fission (asexual) • Eukaryotes- reproduce by mitosis (asexual) and meiosis
BINARY FISSION CELL GROWS & DNA REPLICATES CELL GROWS & STARTS TO DIVIDE CELL DIVISION COMPLETE= 2 IDENTICAL CELLS
Binary Fission • Binary fission is asexual reproduction of a cell by division into two identical cells, unless mutation occurs
Terms • Haploid: a cell with one set of chromosomes • Diploid: a cell with two sets of chromosomes • Gamete: a haploid reproductive cell (ex: sperm and egg) • Zygote: a diploid cell resulting from the fusion of a male and female gamete
Terms • Somatic cell: cells in an organism that are not involved in reproduction • Sister Chromatids: 2 chromosomes that code for the same type of gene and are linked by a centromere • Germ cell: diploid cells in an organism that are involved in reproduction of gametes • Centromere: region of a chromosome that joins two sister chromatids • Chromosome: a long strand of DNA wound tightly with proteins • Homologous pair: two chromosomes that code for the same gene (thing) • Gene: segment of DNA that codes for a protein
http://www.biotechnologyonline.gov.au/biotechnologyonline/popups/int_dnazoom.htmlhttp://www.biotechnologyonline.gov.au/biotechnologyonline/popups/int_dnazoom.html
Cell Cycle Book • Name of the Phase • Picture of the Phase • Colored! • Minimum 2 pairs of chromosomes • Bullet points of what is happening in the phase Example: Interphase • Cell Grows • DNA Replicates • Organelles Duplicate
THE CELL CYCLE HAS 6 PHASES INTERPHASE PROPHASE METAPHASE ANAPHASE TELOPHASE CYTOKINESIS DEVELOP AN ACRONYM TO REMEMBER THE ORDER OF THE PHASES MITOSIS
Mitosis • Mitosis is asexual reproductionof an organism’s non-reproductive cells (somatic cells). • The two newly formed cells are identical to the parent cell, unless a mutation occurred.
Interphase • Before mitosis can happen, the DNA has to replicate, this process is called Interphase. • DNA replicates, producing 2 copies of each chromosome • The organelles also duplicate. • The cell grows
Prophase • Nuclear membrane breaks down • Spindle forms (attaches to centromere) • Centrioles move towards opposite poles • DNA condenses into a chromosome (coils) Interphase Prophase
VARIOUS APPEARANCES OF CHROMOSOMES COILED CHROMOSOMES UNCOILED CHROMOSOMES (CONDENSED)
Metaphase • Chromosomes line up at the middle of the spindle Prophase Metaphase
Anaphase • Chromosomes divide • Individual sister chromatids move to poles Metaphase Anaphase
Telophase • Spindle disappears • Individual nuclear envelopes develop • Chromosomes uncoil (relaxed DNA) • Cell begins to cleave Telophase Anaphase
Cytokinesis Once mitosis is complete the cell splits into 2 identical diploid daughter cells, this process is called cytokinesis
CELL CYCLE Cytokinesis Interphase Prophase Metaphase Anaphase Telophase Mitosis
Videos http://video.google.com/videoplay?docid=8057806780595432977 http://video.google.com/videoplay?docid=728579599035926744&q=mitosis&total=550&start=0&num=10&so=0&type=search&plindex=2
All the cells in a tissue are not in the same phase of mitosis at the same time.
Human cells are programmed to undergo about 50 cell cycles and then they die (apoptosis), only cancer cells have endless cycles
GROWTH FACTORS • GROWTH FACTORS:proteins inside a cell & surrounding a cell’s environment can enhance the growth & division of specific cell types. • CONTACT INHIBITION: when you have a cut or open wound, cells at the edge of the wound begin dividing rapidly to close the gap. They stop dividing when the layer of cells come into contact with the other cell.
Cancer • Cancer is the uncontrollable growth of cells. • A cluster of cells resulting from this uncontrolled growth is called a tumor. • A benign tumor is one that localized in one place in the body • A malignant tumor is one that can spread throughout the body.
EFFECTS OF RADIATION • TREATMENT FOR CANCER PATIENTS • RADIATION BREAKS CHROMOSOMES • THE BROKEN PIECE OF CHROMOSOME WILL CAUSE UNEVEN DISTRIBUTION OF CHROMOSOMAL MATERIAL • THIS WILL CAUSE CELLS TO HAVE TOO FEW OR TOO MANY CHROMOSOME PARTS. • CAN LEAD TO THE CELL’S DEATH.
MORE ON RADIATION EFFECTS • WELL-AIMED RADIATION THERAPY DAMAGES THOSE CELLS THAT DIVIDE MOST RAPIDLY MORE THAN IT HURTS THE PATIENT’S SURROUNDING CELLS. • THERE ARE OTHER RAPIDLY DIVIDING CELLS. EX: SKIN, RED & WHITE BLOOD CELLS, AND CELLS OF THE INTESTINAL LINING.
AFTER EFFECTS/SIDE EFFECTS • THESE CELLS CAN BE DAMAGED DURING RADIATION THERAPY. • SOME SIDE EFFECTS: • ANEMIA (due to too few red blood cells) • SUSCEPTIBILITY TO INFECTION (too few white blood cells) • HAIR LOSS (damaged skin cells) • NAUSEA ( damaged intestinal cells).
Terms • Karyotype:arranging of chromosomes from largest to smallest & pairing up the homologous chromosomes. • Autosomes: all non-sex chromosomes (#1-22 for humans) • Sex Chromosomes- chromosomes that determine the sex of the organism(#23 for humans) • XX= female • XY= male • Set (n): the number of different chromosomes Remember: Haploid = 1 set Diploid = 2 sets
Meiosis • Meiosis is cell division that occurs in an organism’s reproductive cells (germ cells) • The newly formed cells have a variation of the parents DNA (genes) • This is genetic variation
Interphase Just like mitosis, the germ cell must go through interphase, so it’s DNA can replicate before it can begin meiosis.
After interphase, meiosis occurs in 2 stages, with 4 phases each: Meiosis I Meiosis II Prophase I Prophase II Metaphase I Metaphase II Anaphase II Anaphase I Telophase II Telophase I
KARYOTYPE OF A HUMAN Is this person male or female? How many sex chromosomes are present? How many autosome chromosomes are present? How many homologous pairs of chromosomes are present?
Prophase I • Nuclear membrane breaks down • Spindle forms • DNA condenses into chromosomes • Homologous chromosomes pair up • Cross over occurs
Cross over During prophase I, when a pair of homologous chromosomes line up next to each other and a chunk of DNA is exchanged between them. This is how we get genetic variation!!
Metaphase I • Homologous pairs line up at the middle of the spindle
Anaphase I • Chromosome pairs divide • A set of chromosomes moves to each poles
Telophase I • Spindle disappears • Cells begins to cleave