Asexual and Sexual Reproduction

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Asexual and Sexual ReproductionAnimal
Development
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Sexual Reproduction

• There are 1.5 million different types of living
  species known
• Some reproduce sexually, asexually, or both
• Sexual reproduction involves haploid gametes
  coming together and forming a diploid zygote
  (called fertilization)

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Asexual Reproduction

• Spores are haploid reproductive cells that are
  capable of becoming an offspring without fusing
  with another cellit does not involve
  fertilization
• This happens in some molds
• Budding is another form of asexual reproduction
  where a growth of a copy of the adult buds from
  the adult itself until the bud breaks off and
  becomes its own organism
• This happens in yeast
• Fission is another form used by some
  single-celled organisms such as bacteria or
  amoeba
• The organism divides by mitosis to make a new cell

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Protists

• Protists are single-celled eukaryotic organisms
• Earlier this semester I classified Amoeba and
  Paramecium in with the prokaryotes, but this is
  really not true.
• Protozoans are named b/c they are animal-like
  and actually resemble eukaryotes in the way they
  work than prokaryotes like bacteria
• Ex Paramecium can reproduce asexually by fission
  or sexually by conjugation
• Activity 1 on videoscope
• Paramecium (remember they move via cilia)
• Draw a Paramecium not dividing and also one
  dividing by fission on pg. 118

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Fungi

• Fungi are eukaryotic organisms.
• They are also saprophytic (this means they get
  their food from dead organic matter)
• Fungi can be multicellular or unicellular (yeast)
• Some are parasitic (ringworm, athletes foot)

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Fungi

• Rhizopus is a fungus that exhibits sexual and
  asexual reproduction
• It is made up of sections called hyphae
• Can be separated by walls (septate) or not
  separated (aseptate)
• The entire organism forms a mycelium (a mass of
  hyphae)
• Asexual reproduction involves the production of
  sporangia (spores are inside the sporangia)
• Activity 2 Look at prepared slides and draw
  and label the hyphae, mycelium, and sporangium on
  pg. 118

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Fungi

• Yeast
• Yeast are unicellular fungi that reproduce by
  budding
• Budding occurs rapidly under ideal conditions
  (mixed with sugar and water in warm temps)
• (remember the yeast fermentation lab)
• Activity 3 Draw a yeast cell with a bud on pg.
  119

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Animal Reproduction Development (Investigation
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• Asexual Reproduction genetic material of one
  individual is passed onto the next
• Sexual Reproduction genetic material of two
  individuals are combined
• Involves the joining of gametes produced in
  meiosis
• Combining two individuals genes creates
  variability in the population (an advantage in a
  changing environment)
• Asexual Reproduction would only be efficient in a
  highly stable non-changing environment
• Hospitals and MRSA (methicillin resistant Staph
  aureus)

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Reproduction in Hydra

• Hydra have a central body cavity (Phylum
  Cnidaria same as jellyfishradial symmetry)
• Also have tentacles that surround the mouth and
  which are equipped with nematocysts (stinging
  cells)
• They reproduce asexually by budding (same as
  yeast)
• Activity 1 Draw a picture of a budding Hydra on
  pg. 184

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Reproduction in Hydra

• Hydra also reproduce sexually
• Sexual reproduction involves ovaries and testes
  which develop in the outer layer of cells
• Some Hydra have both ovaries and testes, but most
  do not
• Testes are small outgrowths found toward the
  mouth and contain many sperm
• Ovaries are large and round
• Activity 1 contdDraw a sketch of Hydra
  containing ovaries and testes

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Human Reproductive System

• Human male reproductive system functions to
  deliver a haploid gamete (sperm produced by
  meiosis) to an egg (also haploid)
• Sperm
• Are produced in the seminiferous tubules (which
  are tightly coiled forming the testis)
• Are stored in the epididymis
• Pass through the vas deferens to the prostate
  gland and through the urethra of the penis
• The walls of seminiferous tubules are composed of
  cells that undergo meiosis to make sperm
• Activity 2 look at prepared slides of testis
  and sperm and draw on pg. 185 186

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Human Reproductive System

• Female reproductive system functions to produce a
  haploid gamete (egg) and allow for fertilization
  producing a diploid zygote and implantation in
  the uterine wall
• Egg
• Is produced inside the ovary
• Travels down the oviduct (AKA Fallopian tube)
• Implants into the uterine wall
• Single large egg called ovum surrounded by many
  small follicle cells (produce estrogen and
  progesterone)
• When an egg is fully mature, it will rupture
  through the wall of the ovary and pass into the
  oviduct (ovulation) where it is ready to be
  fertilized
• Activity 2 look at prepared slide of ovary and
  draw a mature follicle containing the ovum and
  follicle cells surrounding it on pg. 186

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Animal Development

• When a zygote is formed, it divides by mitosis
  creating 2, 4, and 8 celled stages and then forms
  a mass of cells called a morula
• Further mitosis creates a hollow ball of cells
  called a blastula (1,000 cells)
• Subsequent divisions create tissue layers in the
  gastrula
• Gestation (the period of time it takes for an
  embryo to grow and change into an individual) can
  take no more than 3 weeks for a chicken but up to
  2 years for an elephant
• Humans 9 months

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Animal Development

• Look at prepared slides of the following stages
  of starfish development
• Egg (oocyte)
• 2-cell stage
• 4-cell stage
• 8-cell stage
• Morula
• Blastula
• Gastrula
• Draw these on pg. 191-192

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Sexually Transmitted Diseases

• The spread of STDs is something most people
  ignore and dont think about
• Used to be mainly bacterial infections (syphilis
  or gonnorhea) which are curable
• But now viral infections such as AIDS and herpes
  top the list (Incurable)
• We will do an experiment to see how easily STDs
  can spread

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Whos Dirty?

• There are cups of water and pipettes for everyone
  in class
• ONE person in this class has an STD (glucose in
  their water)
• Everyone is to go around and sleep with only four
  people
• Take ½ pipette full of your water and your
  partner takes ½ of a pipette of theirs and you
  exchange fluids into one anothers cup
• MAKE SURE TO WITHDRAW YOUR ½ PIPETTE OF WATER
  BEFORE YOUR PARTNER EMPTIES THEIRS INTO YOURS
• Keep track of everyone youve slept with (name
  and ) in order
• After sleeping around with four people, have a
  seat and check to see if youre dirty

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Homework

• Homework grade today is your attendance
• Have a great weekend!