chapter 8 the cellular basis of reproduction and inheritance
Download
Skip this Video
Download Presentation
CHAPTER 8 The Cellular Basis of Reproduction and Inheritance

Loading in 2 Seconds...

play fullscreen
1 / 17

CHAPTER 8 The Cellular Basis of Reproduction and Inheritance - PowerPoint PPT Presentation


  • 104 Views
  • Uploaded on

CHAPTER 8 The Cellular Basis of Reproduction and Inheritance. Modules 8.12 – 8.18. MEIOSIS AND CROSSING OVER. 8.12 Chromosomes are matched in homologous pairs. _____ cells of each species contain a specific number of chromosomes

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' CHAPTER 8 The Cellular Basis of Reproduction and Inheritance' - marius


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
8 12 chromosomes are matched in homologous pairs

MEIOSIS AND CROSSING OVER

8.12 Chromosomes are matched in homologous pairs
  • _____ cells of each species contain a specific number of chromosomes
    • Human cells have 46, making up 23 pairs of ________ chromosomes

Chromosomes

Centromere

Sister chromatids

Figure 8.12

8 13 gametes have a single set of chromosomes
8.13 Gametes have a single set of chromosomes
  • Cells with two sets of chromosomes are said to be ______
  • Gametes are ______, with only one set of chromosomes
slide5

Repeated mitotic divisions lead to the development of a mature adult

  • The adult makes haploid gametes by _____
  • All of these processes make up the _____ ___ cycle of organisms
  • At fertilization, a sperm fuses with an egg, forming a diploid ______
slide6

Haploid gametes (n = 23)

Egg cell

  • The human life cycle

Sperm cell

MEIOSIS

FERTILIZATION

Diploidzygote (2n = 46)

Multicellulardiploid adults (2n = 46)

Mitosis anddevelopment

Figure 8.13

8 14 meiosis reduces the chromosome number from diploid to haploid
8.14 Meiosis reduces the chromosome number from diploid to haploid
  • Meiosis, like mitosis, is preceded by chromosome duplication
    • However, in meiosis the cell divides ____ to form _____ daughter cells
slide8

While they are paired, they ____ ___ and exchange genetic information

  • The homologous pairs are then separated, and two daughter cells are produced
  • In the first division, meiosis I, homologous chromosomes are _____
slide10

MEIOSIS I: Homologous chromosomes separate

INTERPHASE

PROPHASE I

METAPHASE I

ANAPHASE I

Centrosomes(withcentriolepairs)

Microtubules attached tokinetochore

Metaphaseplate

Sister chromatidsremain attached

Sites of crossing over

Spindle

Nuclearenvelope

Sisterchromatids

Tetrad

Centromere(with kinetochore)

Homologouschromosomes separate

Chromatin

Figure 8.14, part 1

slide11

The sister ______ of each chromosome separate

  • The result is four haploid daughter cells
  • Meiosis II is essentially the same as ______
slide12

MEIOSIS II: Sister chromatids separate

TELOPHASE IAND CYTOKINESIS

TELOPHASE IIAND CYTOKINESIS

PROPHASE II

METAPHASE II

ANAPHASE II

Cleavagefurrow

Sister chromatidsseparate

Haploiddaughter cellsforming

Figure 8.14, part 2

8 15 review a comparison of mitosis and meiosis
8.15 Review: A comparison of mitosis and meiosis
  • For both processes, chromosomes replicate only once, during interphase
slide14
8.16 Independent orientation of chromosomes in meiosis and random fertilization lead to varied offspring
  • Each chromosome of a homologous pair comes from a different parent
    • Each chromosome thus ____ at many points from the other member of the pair
    • Cross-Over (Does it happen) and where cross-over Occurs
slide15
The large number of possible _______ of chromosome pairs at metaphase I of meiosis leads to many different combinations of chromosomes in gametes
  • _____ fertilization also increases variation in offspring
slide16

POSSIBILITY 1

POSSIBILITY 2

Two equally probable arrangements of chromosomes at metaphase I

Metaphase II

Gametes

Combination 1

Combination 2

Combination 3

Combination 4

Figure 8.16

slide17

Tetrad

Chaisma

Centromere

Figure 8.18A

ad