PLANT & ANIMAL REPRODUCTION

• Reproduction


  process of generating offspring
• two main types of reproduction: sexual and asexual.
• Asexual Reproduction


  a type of reproduction by which offspring arise from a single organism, and inherit the genes of that parent only; it does not involve the fusion of gametes and almost never changes the number of chromosomes.

  
• Binary Fission


  the cell divides into two daughter cells that are similar in size and shape.

  Parent > Nucleus divides (Karyokinesis) > Cytoplasm divides (Cytokinesis) > 2 daughter cell (internal)

  
  

  ex. bacteria
• Vegetative Reproduction


  any form of asexual reproduction occurring in plants in which a new plant grows from a fragment of the parent plant or grows from a specialized reproductive structure. usually involves only the plant’s vegetative structure like roots, stems, and leaves. or flower...
• Sporulation


  Spore formation is another means of asexual reproduction among protozoa and many plants. A spore is a reproductive cell that produces a new organism without fertilization.

  
  

  ex. molds
• Budding 


  a new organism develops from an outgrowth or bud due to cell division at one particular site. The new organism remains attached as it grows, separating from the parent organism only when it is mature, leaving behind scar tissue.

  
  

  ex. hydra
• Gemmules


  internal buds found in sponges, are asexually reproduced mass of cells, that is capable of developing into a new organisms
• Regeneration


  Detached pieces of the parent’s body can develop into a new organism if this body part contains enough genetic information.

  ex. flat worms and starfish
• Sexual Reproduction


  the meeting of 2 portions of DNA possible consequent recombination of physical characteristics in the resulting organism.
• Zygote


  .

  
• A zygote is also referred to as a fertilized egg.
• All gametes are haploid cells, meaning they have only one set of chromosomes (1n).
• when gametes fuse, they form a diploid organism: 1n+1n=2n
• Conjugation in which two similar organisms fuse, exchange genetic material and then break apart. a way for algae to mix their DNA and create variation.
• Alteratioon of Generation

  • Haploid generation (1 set of chromosomes): This part of the cycle reproduces sexually (combining DNA with another haploid).
  • Diploid generation (2 sets of chromosomes): This part reproduces asexually (making identical copies without needing a partner).
• Flowers have male and female parts:

  • Female part = Pistil (includes ovary, ovule, style, and stigma).
  • Male part = Stamen (includes a filament and the anther, which makes pollen).
• Pollination is the process by which pollen is transferred from the anther (male part) to the stigma (female part) of the plant, thereby enabling fertilization and reproduction.
• Perfect Flowers (Self-Pollination):

  • These flowers have both male and female reproductive parts and can fertilize their own ovules without external help
• Imperfect Flowers (Cross-Pollination):

  • These flowers have only one type of reproductive part (male or female) and rely on external factors like wind, insects, or birds to fertilize another flower. staminate or pistilate.
• Animal male gamete is called spermatozoa or sperm.

  Sperm is a mobile cell that moves using its 'tail', called flagellum
• Female gamete is called an ovum.

  It does not move and it is much larger than sperm
• Internal fertilization - eggs are fertilized inside the female's body.

  • lay eggs after fertilization. New offspring develop outside the female's body. = oviparous
  • develop a new embryo inside their body. = viviparous
  • living mammals that lay eggs, rather than bearing live young. = monotremes
• External fertilization - the egg is fertilized outside the female's body. This type of fertilization usually occurs in water.

  ex. Amphibians and fish
• Hermaphrodites - are animals that have both female and male reproductive organs.

  ex. Earthworms and leeches flatworms
• Parthenogenesis - In some animal species, eggs can develop without fertilization or male species.

  ex. bees and turkeys
• Stages of Animal Development

  A. Gametogenesis - spermatogenesis, testis, seminiteous tubules/ oogenesis - ovary

  B. Fertilization - union of gametes (zygote)

  C. Cleavage - cell division

  D. Gastrulation - formation of germ layers

  • Ectoderm (outer layer)
  • Mesoderm (middle layer)
  • Endoderm (inner layer)

  E. Organogenesis

  F. Differentiation

  G. Growth