ch. 13 warm up 1. compare sexual to asexual reproduction. 2. compare/contrast mitosis to meiosis. 3....

46
Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what major processes occur during a sexual life cycle.

Upload: myles-daniels

Post on 21-Jan-2016

216 views

Category:

Documents


0 download

TRANSCRIPT

Page 1: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

Ch. 13 Warm up

1. Compare sexual to asexual

reproduction.

2. Compare/contrast mitosis to meiosis.

3. What are homologous chromosomes?

4. Describe what major processes occur

during a sexual life cycle.

Page 2: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

Ch. 13 Warm up1. Describe and compare the 3 sexual life

cycles

1. How does random assortment, crossing over and random fertilization contribute to genetic variation?

2. Define: locus, karyotype, alternation of generations, synapsis, tetrad, chiasmata

Page 3: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

Warm up1. Describe what occurs during crossing

over.

2. What are 3 sources of genetic variation?

3. Mitosis, Meiosis, or Both?A. Chromosomes line up at metaphase

plateB. Crossing overC. CytokinesisD. Chromosomes are replicatedE. Four haploid daughter cells resultF. Two diploid daughter cells result

Page 4: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

Chapter 13: Meiosis & Sexual Life Cycles

Page 5: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

What you must knowThe difference between asexual and sexual

reproduction.The role of meiosis and fertilization in sexually

reproducing organisms.The importance of homologous chromosomes to meiosis.How the chromosome number is reduced from diploid to

haploid through the stages of meiosis.Three important differences between mitosis and

meiosis.The importance of crossing over, independent

assortment, and random fertilization to increasing genetic variability.

Page 6: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

Types of Reproduction

ASEXUALProduces clones

(genetically identical)Single parentLittle variation in

population - only through mutations

Fast and energy efficient

Eg. budding, binary fission

SEXUALMeiosis produces

gametes (sex cells)2 parents:

male/femaleLots of

variation/diversitySlower and energy

consumptiveEg. humans, trees

Page 7: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

Asexual vs. sexual reproduction

Page 8: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

Genes: segments of DNA that code for basic units of heredity

Offspring acquire genes from parents by inheriting chromosomes

Page 9: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

Chromosomes• Somatic (body) cell: 2n = 46 chromosomes• Each pair of homologous chromosomes includes

1 chromosome from each parent• Autosomes: 22 pairs of chromosomes that do not

determine sex• Sex chromosomes: X and Y• Females: XX• Males: XY

• Gametes (n=23): 22 autosomes + 1 sex chromosome• Egg: 22 + X• Sperm: 22 + X **or** 22 + Y

Page 10: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

Homologous Chromosomes in a Somatic Cell

Page 11: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

Meiosis = reduction divisionMeiosis = reduction division

Cells divide twicetwiceResult: 4

daughter cells, each with half as many chromosomes as parent cell, each daughter cell is genetically unique

Page 12: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

Meiosis IMeiosis I (1st division)Interphase: chromosomes replicatedProphase I: Synapsis: homologous chromosomes pair up Tetrad = 4 sister chromatids Crossing over at the chiasmataMetaphase I: Tetrads line upAnaphase I: Pairs of homologous chromosomes separate (Sister chromatids still attached by

centromere)Telophase I & Cytokinesis: Haploid set of chromosomes in each cell Each chromosome = 2 sister chromatids Some species: chromatin & nucleus reforms

Page 13: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what
Page 14: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

Meiosis IIMeiosis II (2nd division) = create gametes

Prophase II: No interphase No crossing over Spindle formsMetaphase II: Chromosomes line upAnaphase II: Sister chromatids separateTelophase II: 4 haploid cells Nuclei reappear Each daughter cell genetically

unique

Page 15: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what
Page 16: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

Events Unique to Meiosis I (not in mitosis)

1. Prophase I: Synapsis and crossing over

2. Metaphase I: pairs of homologous chromosomes line up on metaphase plate

3. Anaphase I: homologous pairs separate sister chromatids still attached at centromere

Page 17: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

Sources of Genetic Variation:

1. Crossing Over Exchange

genetic material Recombinant

chromosomes

Page 18: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

Sources of Genetic Variation:

2.Independent Assortment of ChromosomesRandom orientation of homologous pairs in

Metaphase I

Page 19: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

Sources of Genetic Variation:

3. Random Fertilization Any sperm + Any egg 8 million X 8 million = 64 trillion

combinations!

Page 20: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

Mitosis Meiosis Both are divisions of cell nucleus

Somatic cells1 division2 diploid daughter cellsClonesFrom zygote to deathPurpose: growth and

repairNo synapsis, crossing

over

Gametes2 divisions4 haploid daughter cellsGenetically different-less

than 1 in 8 million alikeFemales before birth

follicles are formed. Mature ova released beginning puberty

Purpose: Reproduction

Page 21: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what
Page 22: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

Mitosis vs. MeiosisMitosis vs. Meiosis

Page 23: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

Life cycle: reproductive history of organism, from conception production of own offspring

Fertilization and meiosis alternate in sexual life cycles

Meiosis: cell division that reduces # of chromosomes (2n n), creates gametes

Fertilization: combine gametes (sperm + egg)Fertilized egg = zygote (2n)

Zygote divides by mitosis to make multicellular diploid organism

Page 24: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

Varieties of Sexual Life Varieties of Sexual Life CyclesCycles

Page 25: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

Human Life CycleHuman Life Cycle

Page 26: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

AnimalAnimalss

Page 27: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

• Plant and some algae• Sporophyte (2n):

makes haploid spores by meiosis

• Spore gametophyte by mitosis

• Gametophyte (n): makes haploid gametes by mitosis

Alternation of Alternation of GenerationsGenerations

Page 28: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

Fungi, Fungi, protists, protists,

algaealgae

Page 29: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

Karyotype: a picture of an organism’s complete set of chromosomes

Arranged from largest smallest pair

Page 30: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

Making a karyotype – unsorted chromosomes

Page 31: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

22 pairs of autosomes + 1 pair of sex chromosomes

Male or female?

Page 32: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

Male or female?

Page 33: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

Karyotype - used to determine genetic abnormalities

Page 34: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

Cancer cellsSome have abnormal #’s of

chromosomes

Karyotype of Metastatic Melanoma

Page 35: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

Breast Cancer Cell Karyotype

Page 36: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

HeLa CellsOldest and most commonly

used human cell lineCervical cancer cells taken

from Henrietta Lacks (d.1951)

Page 37: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

HeLa Cells“Immortal” cells – do not die

after a few divisionsActive version of telomerase

Used in research:Develop vaccine for polioCancer, AIDS, virus, radiation

research

Estimated that cells produced in culture exceeded # cells in Henrietta’s body

Page 38: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

HeLa Cell Karyotype

Page 39: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what
Page 40: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

HeLa Cells – Ethical ConcernsControversy: Cells harvested

without patient consent“Discarded tissues can be

commercialized” – sold for profit

Genome published in 2013 without family’s consent

“The Immortal Life of Henrietta Lacks” by Rebecca Skloot

Page 41: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

Check for understanding

1.  What phase directly follows metaphase I?

2.  How many cells are present at the end of meiosis I ?

3.  A cell has a diploid number of 60, what is the organism's haploid number? 

4.  Meiosis occurs in what type of cells?

5.  In what phase do homologous chromosomes pair up and crossing-over can occur?

6.  In what phase do the CHROMATIDS separate?

anaphase I

2

30

gametes

prophase 1

anaphase 2

Page 42: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

7.  Identify the phase: 8.  Identify the phase:

anaphase 1 anaphase 2

Page 43: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

Concept Check1. Meiosis results in _____

a. 2 haploid daughter cellsb. 4 haploid daughter cellsc. 2 diploid daughter cellsd. 4 diploid daughter cells

2. Which of the following cells undergo meiosis?a. sperm cellsb. liver cellsc. unicellular organismsd. all of these

3. The picture depicts what phase of meiosisa. prophase 1b. prophase 2c. anaphase 1d. anaphase 2

Page 44: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

Concept Check1. Crossing-over occurs during:

a. anaphase 1b. metaphase 1c. prophase 1d. prophase 2

2. A cell with a diploid number of 24 undergoes meiosis, how many chromosomes are in each daughter cell?

a. 6b. 12c. 24d. 48

Page 45: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

Concept Check

Page 46: Ch. 13 Warm up 1. Compare sexual to asexual reproduction. 2. Compare/contrast mitosis to meiosis. 3. What are homologous chromosomes? 4. Describe what

Name of Phase

Description

1. Homologous chromosomes pair up and form tetrad

2.Spindle fibers move homologous chromosomes to opposite sides

3. Nuclear membrane reforms, cytoplasm divides, 4 daughter cells formed

4. Chromosomes line up along equator, not in homologous pairs

5. Crossing-over occurs

6. Chromatids separate

7. Homologs line up alone equator

8. Cytoplasm divides, 2 daughter cells are formed