Reproductive System

Introduction ► The Reproductive System seeks to ensure the survival of the species. ► Is not essential to life of the animal but for perpetuation of the species. ► Requires a second animal of the opposite sex in order to carry out its functions. ► Complete reproductive system is made up of all the male reproductive organs and structures in one animal and all the femal organs and structures in another.

Fertilization ► The basic reproductive process starts with fertilization ► Fertilization occurs when the ____________________ penetrates the cytoplasm of the ______________  Once egg is fertlized, must be provided with hospitable environment in order to develop.  In order for this to occur both male and female systems must be in sync.  Meiosis is a unique process of cell division that produces spermatazoa and ova.  Is a reduction division of reproductive cells so that a chromosome number goes from a _________number to a ____________ number.  It ensures that each animal’s genetic make up is unique.

 Coiled masses of DNA in nuclei of cells. › Genetic blueprint for all the structures and functions of an animal.  Every cell (except spermatozoa or ova) contains identical chromosomes  Diploid chromosome number (_____) › Total number of chromosomes in nucleus of each body cell is identical (except for reproductive cells) › Is expressed as a 2n number with n being number of chromosomes and 2 indicating the number is doubled. › Always an even number - chromosomes occur in _________.

 Designated as either "X" chromosome or "Y" chromosome  Determine the _______________ of the animal › If both sex chromosomes are X chromosomes (____), the individual is genetically female › If one is an X and the other a Y (_____), the individual is genetically male › YY combination is not possible since all males produce an XY and females only produce XX. ► Full diploid number may be expressed as 2n, XX or 2n, XY.

 Haploid is _______ of the diploid number.  Is abbreviated as n, X or n, Y depending on sex of the chromosome present.  Ensures that fertilized ovum (from union of spermatozoa and ova) has diploid number  Haploid chromosome number in reproductive cells results from ______________  ___________________ Division  total number of chromosomes in each daughter cell is reduced to half the number of parent cell

Meiosis vs. Mitosis ► ____________  Chromosomes ____________ themselves and then pull apart into two daughter cells. Preserves _______________ number.  Ensures that genetic information stays the same throughout all of the body’s cells.

Meiosis vs. Mitosis ► _____________  Do not produce copy before daughter cells are pulled apart.  Therefore ________ of total chromosomes go to each daughter cell.  This makes process entirely random, resulting in unique offspring.

 Production of male sex cells  Occurs in ________________ ____________ of testes  Produced continuously and in very large numbers.

► Begin with cell called ______________ spermatocyte.  Primary spermatocyte has normal diploid number.  Divides by meiosis into two ____________ spermatocytes. ► Now are haploid in number and are pushed to tubule lumen. ► Secondary spermatocytes divide by mitosis into four ___________________. ► 2 will have X markers and two will have Y markers  Sperm dictate gender of offspring.  Now located near center of tubular lumen at this point.  Do not undergo any more cell divisions, but will grow tails and be converted to ___________________ ► Once mature, they detach and will be transported to _______________ for storage before ejaculation.Spermatogenesis

 Production of female sex cells  Occurs in ___________ _________________  ________- female sex cells, are produced in the follicles of the ovaries through process known as ____________________.

► Have fixed number of ____________ oocytes (precursor cells to ova), soon after birth.  Diploid number.  Do not become active until start ovarian cycle. ► Once activated will divide by meiosis.  Division produces a ______________ oocyte and a _____________ body.  Then another mitotic division takes place to become ovum and 3 polar bodies. ► Polar bodies never mature into ovum. Just are where excess chromosomes are stored.  Each cycle produces one or more mature ova.Oogenesis

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