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Published byHoward Lucas Modified over 9 years ago
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Do Now Download Development Honors Notes off of my website
Where’s my money?!?!?! Hand in Meiosis Pictures Lab
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Something to think about as your open up your notes
Humans have approx trillion cells and these cells are all different types (hair, skin, liver, stomach cells, etc.). How can you explain all these types of cells if humans only start as a single cell?
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Animal Reproduction & Development
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Embryology The study of the Embryo An organism in the
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IMPORTANT! RECOMBINATION
Sperm = DNA (haploid) : one version of each type of chromosome. Egg = DNA (haploid): same as above The combination of one sperm with one egg will unite and make . If another sperm or another egg unite, a human would result.
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Recombination: SO MANY OPTIONS!
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3 stages of embryo development
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Oogenesis Unequal meiotic divisions unequal distribution of cytoplasm
What is the advantage of this development system? Oogenesis Unequal meiotic divisions unequal distribution of cytoplasm egg polar bodies Meiosis 1 completed during egg maturation ovulation Meiosis 2 completed triggered by fertilization Put all your egg in one basket!
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Fertilization fertilization cleavage Gastrulation Differentiation
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Fertilization Joining of (nucleus) enters
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1) Cleavage Repeated of zygote 1st step to becoming cellular
unequal divisions establishes body plan different cells receive different portions of egg cytoplasm & therefore different regulatory signals
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Cleavage zygote m b establishes future development blastula zygote
gastrulation morula blastula
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2) Gastrulation Establish 3 cell layers E M
gastrulation in primitive chordates 2) Gastrulation Establish 3 cell layers E outer body tissues skin, nails, teeth nerves, eyes, lining of mouth M middle tissues blood & lymph, bone & notochord, muscle excretory & reproductive systems inner lining digestive system lining of respiratory, excretory & reproductive systems ectoderm mesoderm endoderm protostome vs. deuterostome
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Testing… In a study of the development of frogs, groups of cells in the germ layers of several embryos in the early gastrula stage were stained with five different dyes that do not harm living tissue. After organogenesis (organ formation), the location of the dyes was noted, as shown in the table below. Tissue Stain Brain Red Notochord Yellow Liver Green Lens of the eye Blue Lining of the digestive tract Purple
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Neurulation Formation of notochord & neural tube develop into system
develops into CNS (brain & spinal cord) Neural tube Notochord develops into vertebral column
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Growth and Differentiation
Umbilical blood vessels Mammalian embryo Chorion Bird embryo Amnion Yolk sac Allantois Fetal blood vessels Placenta Maternal blood vessels
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Testing… All of the following correctly describe the fate of the embryonic layers of a vertebrate EXCEPT A. neural tube and epidermis develop from ectoderm B. linings of digestive organs and lungs develop from endoderm C. notochord and kidneys develop from endoderm D. skeletal muscles and heart develop from mesoderm E. reproductive organs and blood vessels develop from mesoderm
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A B C D E F
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3. Growth and Differentiation
As embryo develops, the # of cells continues to Differentiation cells become Different sections of DNA are , some are turned . Certain cells act as organizers These cells influence other cells to become certain cells, tissues
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STEM CELLS Omnipotent = have the potential to be type of cell.
If mitosis is done, all cells are identical. FACT: all of your cells contain the (because of mitosis)
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HOW DO WE GET DIFFERENT CELLS?
Differentiation: some DNA is turned off and only some directions are read, for example: Skin cells: all DNA directions are turned off, except for how to make skin.
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Internal Development Development of the embryo , in the of the body
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Placental Mammals Placenta - part of the wall of the uterus
Site of !!!!!!!!!!!!!!!!!!!!!!!! Embryo’s and mother’s circulatory system are touching BUT NOT
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Umbilical cord Contains that the embryo will get nourishment and oxygen from the mother’s blood to the
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Human fetal development
4 weeks 7 weeks
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Human fetal development
10 weeks
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Human fetal development
12 weeks 20 weeks
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Human fetal development
The fetus just spends much of the 2nd & 3rd trimesters just growing …and doing various flip-turns & kicks inside amniotic fluid Week 20
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Human fetal development
24 weeks (6 months; 2nd trimester) fetus is covered with fine, downy hair called lanugo. Its skin is protected by a waxy material called vernix
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Human fetal development
30 weeks (7.5 months) umbilical cord
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positive feedback Birth
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Getting crowded in there!!
32 weeks (8 months) The fetus sleeps 90-95% of the day & sometimes experiences REM sleep, an indication of dreaming
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Birth (36 weeks)
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And you think 9 months of BioH is hard!
The end of the journey! And you think 9 months of BioH is hard!
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Nonplacental Mammals mammals Duckbilled platypus Anteaters
Embryo begins to develop in uterus Crawls into mother’s pouch Finishes developing in pouch Kangaroo, opossum
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5) Shell – Calcium carbonate,
1) Albumen – S A A E A Y 2) Allantois – 3) Amnion – 4) Yolk – 5) Shell – Calcium carbonate,
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August 08’
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June 08’
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August 07’
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