structure of the gametes
Skip this Video
Download Presentation
Structure of the Gametes

Loading in 2 Seconds...

play fullscreen
1 / 20

Structure of the Gametes - PowerPoint PPT Presentation

  • Uploaded on

Structure of the Gametes. Gilbert Ch. 7 pp. 175-180. Structure of the Gametes: Sperm. Highly Specialized Cell Type!. Parts of mature sperm: Head Haploid nucleus Little cytoplasm Acrosome Neck/Midpiece Mitochondria Centriole Tail (or propulsion system) Some species - ameboid motion

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

PowerPoint Slideshow about ' Structure of the Gametes' - plato-russo

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
structure of the gametes

Structure of the Gametes

Gilbert Ch. 7 pp. 175-180

structure of the gametes sperm
Structure of the Gametes: Sperm

Highly Specialized Cell Type!

  • Parts of mature sperm:
  • Head
    • Haploid nucleus
    • Little cytoplasm
    • Acrosome
  • Neck/Midpiece
    • Mitochondria
    • Centriole
  • Tail (or propulsion system)
    • Some species - ameboid motion
    • Most sperm are propelled by flagella
      • Formed by microtubles
flagella structure
Flagella structure
  • Must allow sperm to travel long distances, using plenty of energy
  • Axoneme: motor portion
    • Microtubules in a 9+2 configuration
      • 2 central microtubules, 9 doublets
      • Made up of the protein tubulin
      • Dyenin molecules attach to microtubules and provide motor activity by hydrolysis of ATP
      • Allows filaments to slide and flagellum to bend
sperm capacitation
Sperm Capacitation
  • Upon release, mammalian sperm are able to move, but do not yet have the capacity to bind an egg
  • Must enter the female reproductive tract to complete the last step of the maturation process (Capacitation) and acquire the ability to bind the egg
structure of gametes the egg
Structure of Gametes: The egg
  • Ovum (mature egg) stores all material for beginning of growth and development
  • Unlike sperm, the egg conserves and acquires more cytoplasm as it matures
  • Synthesizes and stores proteins (like yolk) as reservoirs for the developing embryo
  • The components of the egg vary from species to species
structure of the gametes the egg
Structure of the gametes: The egg
  • Cytoplasm - many components
  • Haploid nucleus
  • Cell membrane
    • will fuse with sperm plasma membrane
  • Vitelline envelope
    • Contains glycoproteins essential for species specificity & sperm binding
  • Zona pellucida (mammals) extra coating made of Extracellular matrix
structure of the gametes the egg cont d
Structure of the Gametes: The egg (cont’d)
  • Cumulus (mammals): layer of cells that nurture the egg
    • Innermost layer is called Corona Radiata
  • Cortex
    • Beneath the cell membrane
    • Gel-like cytoplasm - may help sperm entry into the cell
  • Cortical granules
    • Inside cortex
    • Membrane bound vesicles (like the acrosome in sperm)
    • Help prevent polyspermy
  • Egg jelly (some species)
    • Attract/activate sperm

Eggs are protected by elaborate envelopes

  • Vitelline envelope:a glycoprotein layer covers the plasma membrane of
  • all eggs. This acts to protect the egg.
  • Eggs that are deposited in water have ajelly-like coatingthat surrounds
  • the egg (frogs eggs)
  • Eggs that are deposited on land have particularly elaborate envelopes. The eggs of birds have avitelline envelope, a fibrous layer, an
      • outer layer of albumin (egg white), and a shell composed of calcium carbonate. The outer envelopes are synthesized in the oviduct after the egg has been fertilized.
egg cytoplasm
Egg Cytoplasm
  • Proteins: energy, amino acids
  • mRNA
    • To provide early instructions for development
  • Ribosomes and tRNA
    • To aid in protein synthesis early in development
  • Morphogenetic factors
    • Molecules that effect differentiation of various cell types (can be localized to specific areas of the cell)
  • Protective Chemicals
    • UV filters, DNA repair enzymes, antibodies (birds)