Reproductive System

• Organismal Biology


  it seeks to understand the remarkable diversity of life forms on Earth by analyzing organismal structure and function.
• Reproduction


  it is the production of offspring
• 2 Types of Reproduction

  1. Asexual
  2. Sexual
• Why is Reproduction needed?

  • Reproduction ensures the continuity of the species and keeps it from being extinct.
  • It plays a role in evolution as it creates variations via genetic recombinations.
  • It helps to increase the number of species in the ecosystem.
• Sexual Reproduction

  • use of sex cells (gametes)
  • involves the fusion of male and female gametes to form a zygote
  • genetic variability
• Asexual Reproduction

  • does not involve gametes, instead parts of a mature organism may develop to new individuals
  • offspring is genetically identical to the parent
• 4 Types of Asexual Reproduction

  1. Binary Fission
  2. Budding
  3. Fragmentation
  4. Vegetative Reproduction
• Binary Fission

  • separation of the body into two new bodies
  • common in single-celled organism
• Types of Binary Fission

  1. Amoeba
  2. Euglena
  3. Paramecium
  4. Ceratium
• Amoeba


  irregular binary fission
• Euglena


  longitudinal binary fission
• Paramecium


  transverse binarry fission
• Ceratium


  oblique binary fission
• Steps in Binary Fission

  1. Parent cell
  2. Replication of DNA
  3. Segregation of DNA
  4. Cell splitting into two
• Budding

  • a new organism develops from as an outgrowth from the parent body known as bud
  • Once grown, the new organism detaches from the parent body.
  • example: hydra, saccharomyces cerevisiae
• Steps in Budding

  1. Parent Hydra
  2. Bud arises
  3. Bud grows
  4. Bud develops mouth and tentacles
  5. Bud detaches to form new Hydra
• Fragmentation


  the parent body breaks into several pieces where each piece growns into new individual
• Vegetative Reproduction


  a plant part such as stems, leaves, roots, or turions are used to reproduce new plants
• Vegetative Propagation


  forming a new plant from the part of a parent plant
• Steps in Vegetative Reproduction

  1. Parent plant
  2. Plant cutting
  3. planting
  4. new plant
• Testes


  male reproductive organs
• Seminiferous tubules


  produces sperm (spermatogenesis)
• Oogenesis

  • development of ovarian follicles
  • secretion of estrogen and progesterone
• Fallopian tubes

  • oviducts
  • area where fertilization occurs
• Uterus

  • womb
  • endometrium
  • myometrium
• Animal Development

  1. Gametogenesis
  2. Fertilization
  3. Implantation
  4. Gastrulation
  5. Embryonic Stage
• Gametogenesis


  takes place within the gonads (testes or ovaries); in males this process is called spermatogenesis and produces spermatozoa, while in female it's called oogenesis and results in eggs or oocytes
• Fertilization


  fusion of female gemete with male gamete to form single cell, termed "zygote"
• Implantation


  also known as nidation, is the stage in which embryonic development of mammals in which blastocyst hatches, attaches, adheres, and invades into the wall of the female's uterus
• Gastrulation


  cell movements result in a massive reorganization of the embryo from a simple spherical ball of cells, the blastula, into a multi-layered organism. During this stage, many of the cells at or near the surface of the embryo move to a new, more interior location
• Emrbryonic Stage

  • formation of 4 membranes that supports, protects, and nourish the embryo (yolk sac, allantosis, amnion, and chorion)
  • development of placenta
  • organ formation
• Gonadotrophin

  • releasing hormone (GnRH)
  • stimulates the release of 2 hormones:

  1. Luteinizing Hormone (LH)
  2. Follicle Stimulating Hormone (FSH)
• The Pituitary Gland secretes 2 GnRH hormones:

  1. Follicle Stimulating Hormone (FSH)

  Male: causes the testes to produce sperm

  Female: causes the grown of an ovarian follicle and it causes the follicle cells to secretes estrogen
• Luteinizing Hormone (LH)


  Male: causes testes to secrete testosterone

  Female: causes ovulation and it causes to secrete progesterone
• Stamen

  • male portion of a flower
  • made up fo an anther and a filament
  • the anther produces haploid pollen grains by meiosis
  • most flowers have multiple stamens
• Carpel/Pistil

  • female portion of a flower
  • Has 3 parts:

  1. Stigma
  2. Style
  3. Ovary
• Stigma


  sticky; to trap pollen
• Style


  hollow tube that connects stigma and ovary
• Ovary


  produces female gametes (ovules)
• Parts of a flower

  A) Stigma

  B) style

  C) Carpel/Pistil

  D) ovary

  E) ovule

  F) stem

  G) stamen

  H) anther

  I) filament

  J) petak