Cell Reproduction Intro 1) What do you know about DNA, Genes and Chromosomes? 2) What do you want to...

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?