reproduction at the cellular level (.ppsx)

Chapter 6: Reproduction at the Cellular Level

Kahoot!Get out yoursmartphone/tablet.Establish Wi-FiOpen a browserURL: http://kahoot.it TWO-member teams

http://kahoot.ithttp://getkahoot.com

BIO156Paradise Valley Community College#

BIO156Paradise Valley Community College#Exam Protocols1. Sign out a computer or take out your tablet/laptop.2. Sign on and establish Wi-Fi.3. Open a browser and go to http://socrative.com.4. Select "Student Login" & provide the Room Number: "BIO156".5. Await the Instructor's Start of the exam. You will see a rotating hexagon until that happens.6. Enter your name as Last Name, First Name.You will have 30 minutes to complete the exam.


Todays TopicsAsexual & Sexual ReproductionChromosomes & AllelesThe Cell CycleElements of the Cell CycleUncontrolled Cell DivisionGenomes, Genes, and TraitsCancer and AgingReproduction at the Cellular Level

Chapter 6


3BIO156Paradise Valley Community CollegeReproduction at the Cellular Level

Modes of ReproductionTwo Modes of ReproductionAsexual reproduction Mode by which offspring arise from one parent and inherit that single parents genes onlyOffspring of asexual reproduction are clones.This is mitosis.Sexual reproduction Mode by which offspring arise from two parents and inherit genes from bothThis is meiosis.

BIO156Paradise Valley Community College#4

BIO156Paradise Valley Community CollegeReproduction at the Cellular Level

Prokaryotic Cell divisionNew cells developCytokinesis occursReplication beginsChromatin in nucleoid

Source: Pearson Education, Inc. 2017.

Daughter cells have the same DNA as the parent. (clones)


Eukaryotic ModificationsDNA PackagingSource: Howard Hughes Medical Institute. 2015.

BIO156Paradise Valley Community College#DNA + proteins = chromosomeEvery species has a characteristic genome.Human genome:46 chromosomes23 pairs44 autosomes (22 pairs)2 sex chromosomesGenomeA cells complete complement of DNA + histonesThe Human GenomeSource: National Human Genome Research. 2017.Chromosomes

Karyotype




4 5Homologous chromosomesPairs of chromosomes are homologous.Each copy comes from a different parent.HomologousHaving the same lengthSpecific nucleotide sequenceSame genes at the same loci (sing., locus)

HomologousNon-homologousto chromosomeset #4

Credit: modified from National Human Genome Research. 2017.

Heterologous NOT used


BIO156Paradise Valley Community College#Chromosomes During the Cell CycleHuman somatic cells: 23 pairs of chromosomes. (Latin, soma = body) Except for male sex chromosomes, the chromosomes of each pair are homologous (Latin, homo = same).Homologous Two members of a pairof chromosomes withthe same length, shape,and genes

Source: www.yourarticlelibrary.com. 2015.

Source: galleryhip.com. 2015.

Source: galleryhip.com. 2015.




Introducing AllelesPaired genes on homologous chromosomes vary in DNA sequence as alleles.Alleles are the basis of traits such as hair color, eye color, blood type, flower petal color, etc.Alleles Forms of a gene that encode different versions of the genes product

Credit: Carl Zeiss MicroImaging, 2015.

Alleles




Cell Division & Limb Regeneration

BIO156Paradise Valley Community College#You are Not Who You WereCells lining the alimentary canal (gut)5 daysSkin cells50 daysRed Blood Cells100-120 daysSkeletal cells10 yearsMuscles (intercostal)15.1 yearsCardiomyocytes> 50 yearsBrain cells> 100 years (??)Average cell life span7 to 10 yearsSource: Karolinska Institute, Stockholm, CORDIS, 2005.

BIO156Paradise Valley Community College#The Cell CycleThe Cell Cycleordered series of events involving cell growth andcell divisionthat produces twonew daughter cells.The cell cycle has twomajor phases: InterphaseMitosis

Mitosis

Interphase

S

G2G1

G0

T

A

M

P




Controls of Cell DivisionDifferent types of cells proceed through the cell cycle at different rates.Gene expression controls regulate the cell cycle at different points.Loss of cell cycle controls can result in cancer.

G2

S

G1

G0

T

A

M

P

Mt




The Cell Cycle (24 hours)

G1CellGrowthSGrowth& DNAReplicationProphaseMetaphaseAnaphaseTelophaseCytokinesisG2Growth& PrepInterphase21 hr10 hr6 hr5 hr

RestingStateSource: visualsunlimited.photoshelter.com. 2015.

G0Mt

BIO156Paradise Valley Community College#Late InterphaseAt the end of interphase, a cells duplicated chromosomes condense tightly in preparation for nuclear division (mitosis).Each chromosome consists of two sister chromatids.

Source: blogs.gerbongartwork.com. 2015.one chromatidsister chromatids

Source: visualsunlimited.photoshelter.com. 2015.

centromere




ProphaseProphase Chromosomes condense and spindle forms.Nuclear envelope breaks up.Spindle fibers attach to chromosomes.Spindle Fibers (or Spindle) Dynamically assembledand disassembledmicrotubules that movechromosomes duringnuclear division





MetaphaseMetaphase Duplicated homologous chromosomes line up at the spindle equator(halfway between spindle poles).Sister chromatids begin to move apart toward opposite spindle poles.

Source: visualsunlimited.photoshelter.com. 2015.spindle fibers




Chromosomes at MetaphaseSister chromatidOne of two attached members of a duplicated eukaryotic chromosomeCentromereConstricted region in a eukaryotic chromosome where sister chromatids are attached

Source: Cengage. 2017.

kinetochore




AnaphaseAnaphase Microtubules (spindle fibers) separate the sister chromatids of each chromosome and pull them toward opposite spindle poles.Each DNA moleculeis now a separatechromosome.

Source: visualsunlimited.photoshelter.com. 2015.spindle polesspindle fibers




TelophaseTelophase Two clusters of chromosomes arrive atthe spindle poles andde-condense.New nuclei begin to formEnd of mitosisNuclear envelopes forms(cytokinesis)Two new nuclei with theparental chromosomenumber (2n).






Mitosis Review

ReviewofMitosisSource: Cengage,. 2015.BIO156



Todays TopicsAsexual & Sexual ReproductionChromosomes & AllelesThe Cell CycleElements of the Cell CycleUncontrolled Cell DivisionGenomes, Genes, and TraitsCancer and AgingReproduction at the Cellular Level

Chapter 6



Cancer and the Cell CycleThe cell cycle has built-in checkpoints that allow problems to be corrected before the cycle advances.Checkpoint genes(proto-oncogenes) arecontrols that advance,delay,or blockthe cell cycle in responseto internal and external conditions.

Source: Modified from answers.tutorvista.com. 2015.

CellCycleMisalignment?DNA damaged?DNA not replicated?DNA damaged?


BIO156Paradise Valley Community College#p53 gene Guardian of the GenomeGene responsible for cell cycleregulation

YX22212019181716151413121110987654321Source: www.thecancerblog.com. 2015.

p53


p53Source: Modified from Scripps Research. 2017.

p53DNAp53p53p53Tumor Suppressor GenesCheckpoint ProteinsThey inhibit mitosis and are the product of a class of genes called tumor suppressor genes.Disruption of checkpoint proteins by mutations or viruses causes tumors that may end up as cancer.



Normal Control of the Cell Cycle

p53 accumulationp53 degradationCell cycle arrestAltruisticApoptosisGene mutationsRepairResume cell cycleUV radiation, chemical, oxidative stress

BIO156Paradise Valley Community College#p53 protein Abnormal Control

Repair

Appearanceof abnormalcells (cancer)Cell division continuesw/ mutationsp53 mutationsno accumulationGene mutationsUV radiation, chemical, oxidative stress

BIO156Paradise Valley Community College#p53 gene Guardian of the GenomeIf p53 is damaged, none of the following occurs:p53 Repairs DNA.p53 Puts hold on cell cycle (G1-S0) to allow DNA repair.p53 Causes cell death if DNA is not repairable.

Non Melanoma Skin

Bladder

Ovary

Lymphoma

Leukemia

Esophagus

Head/Neck

Prostrate

Liver

Colon

Breast

Stomach

Lung

70% 45% 20% 60% 20%..10-30% 60% 40% 10% 30% 60% 60% 80%Cancer Cases per annum (X1000) (Developed Countries)p53 MutationsSource: Graphics modified from www.gfmer.ch. 2014.0200400600

BIO156Paradise Valley Community College#p53 repairs DNA.p53 puts hold on cell cycle (G1-S0) to allow DNA repair.p53 causes cell death if DNA is not repairable.


TGCA

The single-letter codes can now be read into a computer to create the genome database.

AGTCCATTACGAAAATCGACTATCGAAGGGTAAAGGCTTATAAGCCATAGTCAGGTAATGCTTTTAGCTGATAGCTTCCCATTTCCGAATATTCGGTATCIts about the code, not the chemistry!

BIO156Paradise Valley Community College#The Human Genome Project

2002Source: www.slideshare.net. 20151990-2002:The Human Genome Project (HGP)The draft human genomesequence was publishedon February 15, 2001.The mouse genome wassequenced 13 months later.Today, roughly 19,000 species have been sequenced. (Source: www.the-scientist.com. 2015)

2001Source: www.slideshare.net. 2015

BIO156Paradise Valley Community College#the Human Genome (Draft)

More to comeNumber of genes: 19,000 to 20,000 Percent of non-coding DNA: 98%

Y

X

22

21

20

19

18

17

16

15

14

13

12

11

10

9

8

7

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5

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3

2

1249,250,621492,449,994690,472,424881,626,7001,062,541,9601,233,657,0271,392,795,6901,539,159,7121,680,373,1431,815,907,8901,950,914,4062,084,766,3012,307,285,7192,199,936,1792,409,817,1112,500,171,8642,581,367,0742,659,444,3222,718,573,3052,781,598,8252,829,728,7202,881,033,2863,036,303,8463,095,693,9811249,250,6212243,199,3733198,022,4304191,154,2765180,915,2606171,115,0677159,138,6638146,364,0229141,213,43110135,534,74711135,006,51612133,851,89513115,169,87814107,349,54015102,531,3921690,354,7531781,195,2101878,077,2481959,128,9832063,025,5202148,129,8952251,304,566X155,270,560Y59,373,566mt16,569Chr#Base Pairs Chr#Base Pairs Cumulative Base Pairs

Source: Modified from schoolbag.info/biology/living/75.html. 2016.

BIO156Paradise Valley Community College#Aging and TelomeresTelomeres contain thousands of repeats of the6-nucleotide sequence, T T A G G G

2009

Source: www.elmundo.es. 2015.

TelomereRegionSource: Modified from yourgenome.org. 2017.


BIO156Paradise Valley Community College#Aging and TelomeresChromosome

Telomeres: end caps thatprotect the chromosome

What repairs telomere loss?The enzyme, telomerase.

BIO156Paradise Valley Community College#Checkpoint ProteinsBRCA1 (breast cancer 1, early onset): tumor suppressor gene whose checkpointproteins normally repair broken DNA

Breast cancer type 1 susceptibility protein(about 27,000 aas)BRCA2BRCA1

Chromosome 13

Chromosome 17

Source: healthfreedoms.org. 2017.



MetastasisCancer cells may metastasize break loose and colonize distant tissues.

Benign tumor

Malignant tumor

Source: Cengage. 2015.Metastasis




Aging and TelomeresTelomere: a region of repetitive nucleotide sequences on end of a chromosomeTelomeres protect the end of the chromosome from deterioration or from fusion with neighboringchromosomes.The Hayflick Limit:Cells die after about 110 cell divisions.

Source: vegsource.com. 2017.




CancerMoles and other tumors are neoplasms.Benign neoplasms arenon-cancerous.A malignant neoplasm(cancer) occurs whenabnormally dividing cellsdisrupt body tissues,physically and metabolically.Malignant neoplasms canbreak free and invadeother tissues (metastasize).

Source: www.buzzle.com. 2015

Source: www.sidereel.com. 2015.

Source: www.biltek.tubitak.gov.tr. 2015.




Three Characteristics of Cancer CellsThree Characteristics of Cancer CellsGrow and divide abnormallyOften have an abnormal plasma membrane, cytoskeleton, or metabolismOften have weakenedcapacity for adhesion

Source: www.alternative-cancer.ne. 2015.




Skin Cancers: Checkpoint FailuresActinic Keratosis (AK) characterized by one or more scaly spots or patches on the top layer of skin.spots or patches maybecome hard with awart-like surfaceEasily removed(e.g., liquid N2 or Levulan)

Source: www.webmd.com. 2015.

Levulan Kerastick BeforeSource: skinmdandbeyond.com. 2017.

Levulan Kerastick AfterSource: skinmdandbeyond.com. 2017.




Skin Cancers: Checkpoint FailuresBasal Cell Carcinoma Most common cancerRarely metastasizes or killsCan cause significant destruction and disfigurement by invading surrounding tissuesIt is considered malignant.

Source: diseasesdoctor.com. 2015.




Skin Cancers: Checkpoint FailuresSquamous Cell Carcinoma a cancer of an epithelial cell, the squamous cellPrimary part of theepidermis of the skinCan also occur in the liningof the digestive tract, lungs,and other areas of the body.

Source: www.webmd.com. 2015.Squamous CellCarcinoma

Basal CellCarcinoma




Skin Cancers: Checkpoint FailuresMelanoma malignant tumor of melanocytes.It is less common thanother skin cancersMuch more dangerousif it is not found early.Causes the majority of deaths related to skin cancer (75%)

Source: www.dermapics.com. 2015.




Tattoos & Skin CancerTattoo inks are not regulated.There is no absolute link to skin cancer and tattoo inks.Will your body react to theinjection of toxins andcarcinogenic ingredientsinto your skin?

Source: tattooremovalpromagazine.com. 2015.



reproduction at the cellular level (.ppsx)

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