Reproductive System

IntroductionIntroduction► 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.

FertilFertilizationization► 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. MitosisMeiosis vs. Mitosis►________________________

Chromosomes ____________ Chromosomes ____________ themselves and then pull themselves and then pull apart into two daughter apart into two daughter cells. Preserves cells. Preserves _______________ number._______________ number.

Ensures that genetic Ensures that genetic information stays the information stays the same throughout all of the same throughout all of the bodybody’’s cells. s cells.

Meiosis vs. MitosisMeiosis 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.

SpermatogenesisSpermatogenesis

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.

OogenesisOogenesis

SUMMARY