cell reproduction intro 1) what do you know about dna, genes and chromosomes? 2) what do you want to...
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Cell Reproduction Intro
1) What do you know about DNA, Genes and Chromosomes?
2) What do you want to learn about DNA, Genes and Chromosomes?
1/29/14 Find your new seats!
Bellringer: Cell Reproduction Intro
Chromosome Notes
HW: Karyotype Worksheet due Tomorrow
Chromosomes!!!
Introduction to Chromosomes All of a cell’s DNA is called its “genome” This genome contains all of the instructions for
cell/organism survival and function A typical human cell has about 3 meters of
DNA DNA is packaged into chromosomes
Chromosomes PROKARYOTIC
Chromosomes are simple circles/clumps of DNA
Chromosomes EUKARYOITC
Chromosomes are very complex
The whole chromosome is made of DNA coiled around proteins called histones
Chromosomes Homologous Chromosomes:
The pairs of chromosomes that exist in sexually reproducing species
In each pair of h. chromosomes one chromosome comes from each parent
They are each called autosomes, and are identical (except X and Y, the sex chromosomes)
Homologous Chromosomes Homologous
chromosomes contain genes for the same traits
Gene: A section of DNA that codes for a specific trait Ex: Hair color
Homologous Chromosomes Before a cell
divides, the chromosomes copy themselves
The two copies are called chromatids (or sister chromatids), and are attached to one another by a centromere
aA A Aa a
Alleles are different forms of the same gene
replication
1 chromosome
Karyotype A picture of all the chromosomes. It is used to look for abnormalities
Revisit Goals1) Find 1-2 goals that you did not meet (or are off-track) …Explain why you didn’t
reach these goals
2) Find 1-2 goals that you did meet (or are on-track) …Explain why you did reach these goals
3) Make at least 6 second semester goals on your goal sheet (measurable)2+ Academic2+ Personal Improvement 2+ Work/Family/Relationships/Clubs
1/30/14 Bellringer: Goals HW: New Goals
Chromosome Notes (Chromosomal Disorders) Go over karytype WS Introduce Chromosomal Disorders Brochure
Straight to the Library tomorrow
Chromosome Number Number varies by species The number of chromosomes in a SOMATIC CELL
(normal body cells) in an organism is known as the DIPLOID/2N number
GAMETES (sex cells, sperm/eggs) contain only half the number of chromosomes and are known as the HAPLOID/N number
Complexity Rankings
Rank the below organisms from least to most complex Humans, Crabs, Potato, Camels, Squirrels, Chickens,
Fruit flies, Tomato
Explain the reason behind your rankings.
DIPLOID # OF CHROMOSOMES BY SPECIES:
CAMEL = 70 SQUIRREL = 40 CHICKEN = 78 KING CRAB = 208 FRUIT FLY = 8 TOMATO = 24 POTATO = 48 HUMAN = 46
Human Chromosome Number Human Haploid (N) Number: 23 Human Diploid (2N) Number: 46 A human must have all 46 chromosomes to
function “properly” In most cases, humans missing even one
chromosome don’t survive development Monosomy: missing a chromosome Trisomy: having an extra chromosome
Nondisjunction: when homologous pairs or sister chromatids fail to separate
Down’s syndrome: (trisomy 21) 3 copies of the 21’st chromosome
Cri-du-chat: deletion at the 5th pair
Klinefelter:Extra X chromosome
Goals: Review Goals and Make new ones…
1/31/14 Bellringer: Goals
Go Straight to LIBRARY
Work on Karyotype Worksheet and Brochure…
Bellringer Define the word “cycle”. What is the cell cycle? If you don’t know, what
would you guess it includes? Are all cell cycles the same?
2/3/14 Objective: To introduce the cell cycle
Bellringer: “Cycle” Cell Cycle Notes
Homework: Chromosome WS
Cell Division
Cell Division Cells divide in order to
repair or replace cells that die
Also create new cells in development of a multicellular organism that begins as a zygote
Cell Cycle Cell Cycle: The life cycle of the cell,
from division to division of a cell5 Stages of the Cell Cycle:n G1: Growth phase of the celln S: DNA is copiedn G2: Prep for mitosis, and organelles
are copiedn M: Mitosis occurs, nucleus dividesn C: Cytokinesis, cell/cytoplasm divides
Inte
rphase
MOST OF A CELLS LIFE IS SPENT IN INTERPHASE
What Triggers Cell Division? Size: If a cell grows so large that there is too
much volume for its surface area, it will divide Growth factors: Chemicals released by cells
that encourage other cells to divide
Cell Division There are 2 types of cell division
MITOSIS: Produces identical cells Occurs in body cells Makes diploid cells
2 Types of Cell DivisionMEIOSIS: Produces sex cells (gametes) Occurs in cells of the sex organs Makes haploid cells
Bellringer Define cell cycle We know cellular division is part of the cell
cycle. Name one thing that you think happens during cell division.
2/4/14 Bellringer: Cell Cycle
Turn in Chromosome Worksheet
Onion Cell Pre-lab (due Friday)
Bellringer….
2/5/14 Bellringer: ?????
Computer Lab Activity
These are the stages of mitosis. Put them in order, and have a rational for why (you don’t need to write it, but I will ask.)
A
ED
CB
2/6/14 Bellringer: Stages of Mitosis
MITOSIS NOTES
Homework: Finish Pre-Lab (I’ll explain later)
Stages of Mitosis
Stage 1:Prophase Chromosomes appear Nuclear envelope
breaks down Spindle fibers appear
Spindle fibers are protein ropes that help pull chromosomes apart
Late prophase – you can see the spindle fibersLate prophase – you can see the spindle fibers
Stages of Mitosis
Stage 2: Metaphase Meta means “middle” Spindle fibers line up
chromosomes on the equator They attach to the
centromeres
MetaphaseMetaphase
Stages of Mitosis
Stage 3: Anaphase Sister chromatids are
pulled apart by spindle fibers
Each chromatid (now a chromosome) moves to opposite poles (centrioles)
Stages of Mitosis
Stage 4: Telophase Chromosomes uncoil on
separate sides of the cell
New nuclear envelope appears
Cytokinesis: After Mitosis
Cytokinesis: Cell membrane grows in
to enclose both cells; cytoplasm divides
In plants, a new cell wall must form
Mitosis produces two identical daughter cells which are diploid
Mitosis in Onion Root
These are the stages of mitosis. Put them in order, and have a rational for why (you don’t need to write it, but I will ask.)
A
ED
CB
Mitosis overview
Homework Somewhere on the pre-lab from yesterday, do
the following: Label each cell drawing 1-9 as interphase,
prophase, metaphase, anaphase, telophase, and cytokinesis
You don’t have to use every phase
Bellringer Define Mitosis Define chromosome What kind of cells did we look at in the lab
from the last few days?
2/7/14 Bellringer: Definitions
Onion Lab
Homework: Lab due Monday
Mitosis in Onion Root Mitosis in Onion Root
Bellringer Define haploid and diploid
Why do we want our sex cells (sperm and eggs) to be haploid?
2/10/14 Bellringer: No Bellringers This week….
Agenda: Discuss week Notes on meiosis
Sub all week.. Tuesday: Work on Flipbook Wednesday: No School (Lincoln) Thursday: Cancer Article / Questions Friday: Meiosis/Mitosis Worksheet &
Study Guide*
*I’m back Monday, exam is Tuesday
Meiosis Meiosis is a special kind of cell division that
produces our gametes (sex cells, sperm and egg)
Occurs in testes and ovaries
1 diploid cell(2n) →4 haploid cells (n)
Fertilization creates a zygote and restores the diploid condition
Egg (n) + sperm (n) →→ Zygote (2n)
Meiosis Overview
There are 2 cell divisions in Meiosis:
1. Meiosis I: DNA replicates, and homologous chromosomes are separated
1. Same amount of DNA is started with
2. Meiosis II: Same steps as mitosis, but without DNA being replicated beforehand
• Sister chromatids are separated
Meiosis
Crossing Over During Meiosis 1, Homologous pairs form their
sister chromatids The two pairs of chromatids line up together in
what is called a tetrad. When they do this, crossing-over occurs
Homologs swap small pieces of genetic info
Independent Assortment Independent
assortment: mom’s chromosomes don’t always go to same side nor do dad’s
Crossing over and Independent Assortment leads to greater genetic diversity, which is good for populations!!!
Bellringer “If children have the ability to ignore all
odds and percentages, then maybe we can all learn from them. When you think about it, what other choice is there but to hope? We have two options, medically and emotionally: give up, or Fight Like Hell.”
What triggers cells to divide/start mitosis? What could trigger them to stop? What do you know about cancer? Do you know
someone who has had it?
Agenda Objective: To discuss cancer Agenda:
Bellringer/Discussion Notes Grade WS Assign Mitosis Wheel and Practice
Homework: WS due Tomorrow Wheel due Monday
What Stops Cell Division? Density-dependent inhibition: Cells stop
dividing when crowded Cancer cells do not respond to normal cell
cycle regulation
Tumors Tumor cells are the result of uncontrolled cell
division (they are a big “lump” of cells) Benign tumors: non-harmful Malignant tumors: harmful
Cancer kills because a tumor makes some essential part (lung, heart, etc…) stop working right
TumorsTumors
Malignant Tumors Cells divide without control and can invade
other tissues (metastasize). Cancer cells can spread to other parts of the
body through the blood and lymph systems.
Cancer Types Carcinoma: begins in the skin or in tissues
that line or cover internal organs. Sarcoma: begins in bone, cartilage, fat,
muscle, blood vessels, etc Leukemia: starts in blood-forming tissue such
as the bone marrow Lymphoma and myeloma: begin in the cells
of the immune system. Central nervous system cancers: begin in
the tissues of the brain and spinal cord
Lung CancerLung Cancer
Cancerous Lung Healthy Lung
Skin CancerSkin Cancer
DetectionDetection
Treatments Chemotherapy Radiation treatment Surgical removal of tumors Immunotherapy Blood and marrow transplant
** There is NO cure for cancer **
Bellringer What components need to be in your psych
lab report? What are the characteristics of a good
materials section? What are the characteristics of a good
procedure? What formatting applies?
Bellringer What would you guess is the most common
form of cancer? What do you think is the most lethal spot for
cancer?
Agenda Objective: To talk a bit more about cancer,
and begin reviewing Agenda:
Bellringer/Discussion Talk cancer rates Grade Mitosis WS Assign Practice WS and wheel
Homework: Wheel due Monday, WS due tomorrow
Common Forms of CancerCommon Forms of Cancer
Self Checks
All: CHECK YOURSELF! Colonoscopy once every 10 years after turning 40-50
Women: Monthly breast self-exam once you start menstruating Yearly gynecology visits for pelvic exam and pap smear
after the age of 21
Men: Monthly testicular exam at age 14
Bellringer Get out your study guide. What areas are you most concerned about? What areas are you least concerned about?
Comparing Mitosis and Meiosis
Determine whether the following characteristics apply to mitosis, meiosis, or both, by putting a check in
the appropriate column. Advice: be consistent in your answers!
Mitosis Meiosis
1.no pairing of homologous chromosomes 1. ______ _______
2.two divisions 2. ______ _______
3.four daughter cells are produced 3. ______ _______
4.associated with growth and a-sexual reproduction 4. ______ _______
5.associated with sexual reproduction 5. ______ _______
6.one division 6. ______ _______
7.two daughter cells are produced 7. ______ _______
8.involves duplication of chromosomes 8. ______ _______
9.chromosome number is maintained 9. ______ _______
10.crossing over between homologous chromosomes may occur
10.______ _______
11.chromosome number is reduced to half 11.______ _______
12.daughter cells are identical to parent cell 12.______ _______
13.daughter cells are not identical to parent cell 13.______ _______
14.produces gametes 14.______ _______
15.synapsis occurs in prophase 15.______ _______
.A. B. C.
N (haploid): ______Body cell: ______Gamete cell: ______
N (haploid): ______Body cell: ______Gamete cell: ______
N (haploid): ______Body cell: ______Gamete cell: ______
Chromosome numbersThe three figures describe chromosomes of three different organisms. For each one - What is the haploid number (N) of chromosomes? How many chromosome would you find in a regular body cell? How many in an egg or in a sperm cell?
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