• Archiv der Kategorie: Entwicklungsbiologie

Mars versus Venus? Part 6: Animal Love Story

In the previous parts we have either dealt with absurd “philosophical” views (Butler’s queer theory or Kutschera’s sympathies for AfD and Catholic church reactionaries) or have penetrated deep into genetics. At this point, we now deal with mating systems in the animal kingdom. Anyone who has an interest in how diverse the sex life of animals is without much scientific “Blabla”, I can only recommend “Das Liebesleben der Tiere (The Love Life of Animals)” by Katherina von der Gathen.

In a pedagogically meaningful and child-friendly way, without being obscene, the reproductive behavior of different animals is addressed, from mate choice to rearing of the offspring everything is there: funny, beautifully illustrated and oriented on facts.

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Mars vs. Venus? Part 3: File number XY … solved!

Summary of parts one and two

  1. We humans (and most living beings) have a double set of chromosomes (= diploid). And that’s essentially true of most creatures, especially animals.
    2. We humans produce, like all sexually reproducing organisms, germ cells (= gametes). These have only half a chromosome set (= haploid). The process of producing four haploid cells from a diploid cell is called meiosis (or reduction division).
    3. We produce two different types of germ cells, sperm cells (small, motile) and oocytes (large, immobile). This applies to ALL animals. Other groups of organisms also produce different germ cells (always two), or they produce equivalent germ cells (isogamy), where always two merge into one zygote (but isogamy is generally uninteresting for humans and animals).
    4. Living beings undergo a change in the haploid and diploid phase (= biological life cycle) in their lives. Depending on the type one phase outweighs the other phase. In humans and all animals the diploid phase dominates (= diplonts).
    5. Each germ cell production coincides with a “germ cell production site”. Sperm is produced in animals in testicles, oocytes in ovaries. This is also associated with the proliferation of germ cells (internal or external fertilization, ovarian apparatus, penis, etc.).
    6. If there are living things that have three or more sets of chromosomes (= polyploid), they are a special case due to disorders during meiosis. But always two types of germ cells are created.

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Von der Zygote zur Larve in 6 Minuten

Der Bergmolch (Ichthyosaura alpestris) Lurch des Jahres 2019gehört zu den Schwanzlurchen (Caudata) innerhalb der Klasse der Amphibia. er kommt in weiten Teilen Europas vor und ist zum geworden.

Das Video “Becoming” (“Werden”) von Jan van Ilken zeigt die Entwicklung eines Bergmolches von der befruchteten Eizelle zur fertig entwickelten Larve. “Becoming” ist ein wunderschönes Video, dass den Prozess der Zellteilung- und differenzierung in der Emtwicklungsbiologie aufzeigt. Einem Prozess, dass jedes Lebewesen durchgehen muss.das Video kann man sich hier ansehen:

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