7/25/2019 Ch._13_Handout_2011 ppt

1/39

M

eiosis&

SexualReprod

uction

(Ch.

13)

7/25/2019 Ch._13_Handout_2011 ppt

2/39

Celldivision/As

exual

reproduction

Mitosis

produ

cecellswit

hsameinfo

rmation

iden

ticaldaughte

rcells

_________________

clon

es

same

amountof

DNA

___

___________

_____________

___

___________

_____________

Aaaargh!

Im

seeing

d

b l !

7/25/2019 Ch._13_Handout_2011 ppt

3/39

Asexualrep

roduction

Single-c

elledeukaryotes

yeast

(fungi)

Protis

ts

Paramecium

Amo

eba

Simplemulticellular

eukaryo

tes

Hydra

Whatarethe

disadvantageso

f

asexual

reproduction?

Whatarethe

budding

budding

7/25/2019 Ch._13_Handout_2011 ppt

4/39

Howabouttherestofus?

What

ifacomplexmultice

llular

organ

ism(likeu

s)wantstoreprodu

ce?

join

ingofegg+

sperm

Dowemakeeg

g&sperm

bymitosis?

46

46

+

92

egg

sperm

zyg

ote

Whatifwe

did,

then.

7/25/2019 Ch._13_Handout_2011 ppt

5/39

Hu

manfemale

_______________

46

chro

mosomes

23pairs

7/25/2019 Ch._13_Handout_2011 ppt

6/39

Hu

manmale________________

46

chro

mosomes

23pairs

7/25/2019 Ch._13_Handout_2011 ppt

7/39

Hom

ologou

schrom

osomes

Pairedchromosome

s

bothc

hromosomesofapair

carrymatc

hing

genes

controlsameinhe

ritedcharacte

rs

hom

ologous=_____________

____

diplo

id

2n2n=

4

single

stranded

h

omologous

chromosomes

doublest

randed

h l

7/25/2019 Ch._13_Handout_2011 ppt

8/39

How

dowema

kespe

rm&

eggs

?

Mus

tre

duce

46chromosomes

23

mus

tre

duce

the

num

berof

chromosom

es

by

____

______

2

3

2

3

46

egg

spe

rm

46

me

iosis

46

fertiliza

tion

23

23

__________

7/25/2019 Ch._13_Handout_2011 ppt

9/39

Meio

sis:productiono

fgamet

es

Meiosis

chrom

osomenum

ber

mustbereduced

______________

___

______

humans:46

23

mak

es____________

___________

restor

eschromos

ome

numb

er

haploiddiploid

n2n

________

________

7/25/2019 Ch._13_Handout_2011 ppt

10/39

Sexualrepr

oductio

n

lifecycle

!

1copy

!

haploid

!

1n

!

2 copies

!

diploid

!

2n

!

1copy

!

haploid

!

1n

__________

___________

_ Inthenext

generation

Weremixing

thingsup

here!

A

good

thing?

gametes

gametes

7/25/2019 Ch._13_Handout_2011 ppt

11/39

M

eiosis

_______

_________

___

specialcelldivision

forse

xual

repro

duction

reduc

e2n1n

diploid

haploid

twohalf

_________________

spe

rm,eggs

Warn

ing:me

ios

ise

vo

lve

dfrom

mitos

is,s

o

stages

&mac

hinery

ares

imilar

bu

tthe

process

esarera

dica

lly

differen

t.Dono

t

7/25/2019 Ch._13_Handout_2011 ppt

12/39

Overview

ofm

eiosis

I.P.M.A.T

.P.M.A.T

interphase

1

prophase

1

meta

phase

1

anaphase

1

telophase

prophase

2

metaphase

2

anaphase

2

telophase

2

2n=

4

n=2

n=2

n=2

7/25/2019 Ch._13_Handout_2011 ppt

13/39

2nd

divisionof

meiosissepara

tes

_____________

______

1st

divisionof

mei

osissepara

tes

_____________

______

Dou

bledivision

ofmeiosis

D

NAreplication

Meios

is1

Meios

is2

7/25/2019 Ch._13_Handout_2011 ppt

14/39

2n=6

double

s t r a n d e d

2n=6

single

stranded

Prepa

ringfor

meiosis

1ststep

ofmeiosis

DuplicationofDN

A

Whybother?

meiosisevolvedaftermitosis

convenienttouse

ma

chineryofm

itosis

DNA

replicatedin

Sphaseof____________

of_

___________

__

(jus

tlikeinmitosis)

M1propha

se

7/25/2019 Ch._13_Handout_2011 ppt

15/39

2n=___

single

stranded

Meiosis1

2n=___

double

stranded

proph

ase1

______

_______

ofmeiosis

separa

tes_______________

tetrad

synapsis

1n=___

double

t d d

telophase1

2n=___

double

stranded

metaph

ase1

reduction

7/25/2019 Ch._13_Handout_2011 ppt

16/39

Meiosis2

1n=___

double

stranded

metap

hase2

1n=__

_

single

strande

d

t l

h

2

prophase2

1n=___

double

stranded

_____

________

_ofmeios

is

separates______

_____________

Whatdoes

thisdivision

looklike?

4

7/25/2019 Ch._13_Handout_2011 ppt

17/39

Steps

ofmeiosis

Meios

is1

inte

rphase

prophase1

met

aphase1

ana

phase1

telo

phase1

Meios

is2

prophase2

met

aphase2

ana

phase2

telo

phase2

2nddiv

isionofmeiosis

separat

es___________

____________________

(1n

1n)

*justlikemitosis*

1stdivisionof

meiosis

separates

____________________

(2n

1n)

reduct

iondivision

7/25/2019 Ch._13_Handout_2011 ppt

18/39

Meiosis1&

2

7/25/2019 Ch._13_Handout_2011 ppt

19/39

Tra

ding

pieces

ofDNA

_______________

_____

during_

____________,sister

chromatidsintertwin

e

homologouspairss

wap

piecesofchromoso

me

DNAbreaks&re-at

taches

_

_______

____________

___

prophase

1

7/25/2019 Ch._13_Handout_2011 ppt

20/39

Cros

singov

er

3steps

crosso

ver

breakageofDNA

re-fusin

gofDNA

_______________

________

____

Whatarethe

advantagesof

crossingoverin

sexual

reproduction?

7/25/2019 Ch._13_Handout_2011 ppt

21/39

M

itosisv

s.

Meio

sis

7/25/2019 Ch._13_Handout_2011 ppt

22/39

Mitosis

vs.

Me

iosis

Mitosis

___

division

daug

htercells

gene

tically______

__

topa

rentcell

prod

uces_________

____

____

prod

uces_________

____

___________

__

nocrossingover

Meiosis

___

division

daughtercells

g

enetically___________

fromp

arent

produces_________

________

produces____________

___________

________

7/25/2019 Ch._13_Handout_2011 ppt

23/39

____

_______

z

ygote

Puttingitalltogether

23

23

46

egg

sperm

46 _

_______

46

23

23

________

___

development

meios

isfertilizationmitosis+developm

ent

46

46

46

46

46 4

6

46

46

gametes

7/25/2019 Ch._13_Handout_2011 ppt

24/39

Sexualrep

roductionintroducesgen

eticvariation

_______

__________

________

______

_______________

ofchromoso

mes

rand

oma

lignmentofhomologouschrom

osomesinMetap

hase1

_______

__________

____

mixing

ofallelesacross

homologousch

romosomes

_______

__________

____

whichs

permf

ertilizesw

hichegg?

Drivingevolution

providingvariationfor

naturalselec

tion

Theva

lueo

fs

exua

lre

pro

duc

tion

metaphase1

7/25/2019 Ch._13_Handout_2011 ppt

25/39

V

ariation

fromg

eneticrecombinatio

Indepen

dentasso

rtmentofchromosomes

meios

isintroduce

sgeneticvariation

game

tesofoffspringdonoth

avesame

combinationofge

nesasgam

etesfromp

arents

rand

oma

ssortmentinhumans

produces

______________

differentcom

binationsing

ametes

f r

o m

D a d

f

r o m

M o m

o f f s p r i n g

newg

ametes

m a d e b y

o f f s p r i n g

7/25/2019 Ch._13_Handout_2011 ppt

26/39

Variationfromc

ros

singov

er

Crossingovercreatescomp

letelynew

combina

tionsoftr

aitsoneachchromo

some

create

san___________

variety

ingametes

7/25/2019 Ch._13_Handout_2011 ppt

27/39

Variatio

nfromr

andom

fertiliz

ation

Sperm

+Egg=

?

any

2parentsw

illproduce

azygotewith

over70trillion(_________

_)possible

diploid

com

binations(notevencountingcross

ing

over!!!!!!!!!)

7/25/2019 Ch._13_Handout_2011 ppt

28/39

Sexualreproduct

ioncreate

svariabil

ity

Sexualre

productionallowsustomaintainboth

genetics

imilarity&differences.

B

l d

i

b t h

Jonas

Brothers

M

t i

& C h

l i

S h

E

i l i

E

t

7/25/2019 Ch._13_Handout_2011 ppt

29/39

Sperm

production

Ep

ididym

i

s

Tes

tis

Co

ile

d

sem

iniferou

s tubu

les

Vas

de

ferens

Cross-sec

tiono

f

sem

iniferous

tubu

le

sperma

tozo

a

sperma

tid

s

(hap

loid)

secon

dary

s

perma

tocy

te

s

(hap

loid)

primary

sperma

tocy

t

e

(diploid)

germ

ce

ll

(diploid)

MEIOSIS

II

MEIOSIS

I

Spermatogenesis

continuous&prolificprocess

eachejaculation=

100-600m

illionsperm

7/25/2019 Ch._13_Handout_2011 ppt

30/39

Eggproduction

Meiosis

1completed

duringe

gg

maturation

Meiosis2

completed

t r i g g e r e d

b y

ovulation

Oogenesis

eggsin

ovarieshalte

d

beforeAnaphase1

Meiosis

1completed

duringm

aturation

Meiosis

2completed

afterfertilization

1egg+

2polarbodie

s

unequal

division

s

7/25/2019 Ch._13_Handout_2011 ppt

31/39

Oogenesis

MEIOSIS

I MEIOSIS

II

firs

tpo

lar

bo

dy

sec

on

d

polar

bo

dy

o

vum

(h

ap

loid

)

secon

dar

y

oocy

te

(haplo

id)

primary

oocy

te

(diploid

)

germ

ina

l

ce

ll

(diploid)

primary

follicles

ma

ture

follicle

with

secon

daryoocy

te

rup

ture

d

follicle

(ovu

lation

)

corpus

luteumd

eve

lopin

g follicle

fe

rtiliza

tio

n

fallop

ian

tube

after

fert

iliza

tion

Puttinga

ll

your

eg

g

in

one

bas

ket!

7/25/2019 Ch._13_Handout_2011 ppt

32/39

Diffe

rences

across

kingdoms

No

ta

llo

rgan

isms

use

hap

loid

&diploidsta

ges

insameway

wh

ichone

isdom

inan

t(2nor

n)differs

bu

ts

till

alternate

be

tween

hap

loid&diploid

mus

tforsexua

lre

pro

duc

tion

7/25/2019 Ch._13_Handout_2011 ppt

33/39

Whatare

the

DISadvantagesof

sexual

reproduct

ion?

EggsarePrecious,

SpermisCheap.

AnyQu

estions?

?

7/25/2019 Ch._13_Handout_2011 ppt

34/39

Revie

w

Questio

ns

7/25/2019 Ch._13_Handout_2011 ppt

35/39

1.

Howdo

cellsatthe

completion

ofmeiosis

compar

ewithcells

thathavereplicatedtheir

DNAan

darejusta

bouttobeginmeiosis?

Theyhav

etwicetheamountofcytoplasman

dhalftheamount

ofDNA.

Theyhav

ehalfthenumberofchromosomes

andhalftheamou

ntof

DNA.

Theyhav

ethesamenumb

erofchromosome

sandhalftheam

ountof

DNA.

Theyhav

ehalfthenumberofchromosomes

andone-fourthth

eamount

ofDNA.

Theyhav

ehalftheamountofcytoplasma

nd

twicetheamount

ofDNA.

7/25/2019 Ch._13_Handout_2011 ppt

36/39

2.

WhichnumberrepresentsG2?*

I IIIII

IVV

7/25/2019 Ch._13_Handout_2011 ppt

37/39

3..

WhichnumberrepresentstheDNAc

ontentofasp

erm

cell?

I IIIII

IVV

7/25/2019 Ch._13_Handout_2011 ppt

38/39

4.

Which

ofthe

followingwou

ldnot

becons

idere

da

haplo

idce

ll?

A

.

daug

hterce

lla

fterme

ios

isII

B

.

game

te

C

.

daug

hterce

lla

fterm

itos

isingametop

hy

tegenera

tion

ofap

lan

t

D

.

ce

llinprop

haseI

E

.

ce

llinprop

haseII

7/25/2019 Ch._13_Handout_2011 ppt

39/39

Ace

llin

G2be

fore

me

ios

iscompare

dw

ith

oneo

f

the

four

ce

llspro

du

ce

dby

that

me

iotic

division

has

twic

easmuchDNA

andtwiceasma

nychromosome

s.

four

timesasmuchDNAandtwicea

smanychromosomes.

four

timesasmuchDNAandfourtim

esasmanychromosomes.

half

asmuchDNAb

utthesamenum

berofchromos

omes.

half

asmuchDNAa

ndhalfasmany

chromosomes.