About This Chapter
Animal Reproduction and Development
How are babies made? Rather than being just an awkward question that small children ask their parents, this inquiry forms the backbone for the study of animal reproduction and development. Our lessons start with an overview of reproduction that covers fertilization and gametogenesis. Take a closer look at spermatogenesis and oogenesis, the cell division and differentiation that results in mature sperm cells and eggs. The common word root genesis lets you know that this is just the beginning.
With our lesson on spermatogenesis, you can trace the progression from spermatogonia to spermatocytes to spermatids to fully mature sperm cells. Don't worry; we also have a lesson on oogenesis, the rather intricate creation of egg cells, to balance out all that sperm! Both lessons also include a handy review of meiosis to strengthen and test your new vocabulary. Now that we have all the players in place, egg and sperm can meet, and we can examine the results of this fertilization.
Our lesson on cleavage and gastrulation gives you a glimpse at the early stages of embryonic development. Watch as cleavage, that rapid division of cells in the developing embryo, results in the formation of a blastula. Wait, how do you tell the difference between a blastula and a gastrula? Once you understand the three germ layers, this difference won't elude you. From ectoderm to mesoderm to endoderm, each germ layer is responsible for giving rise to sets of tissues and organs. See which sets each germ layer can create.
Every developing embryo needs nourishment, protection and a way to store waste. Our lessons cover the extraembryonic membranes and placenta that make this possible. Study how the amnion protects the embryo from outside impacts, and learn how placenta allows a fetus and its mother's body to exchange substances. We also look at embryonic organization. See how a fate map tries to trace the origin of tissues back to different stages of embryonic development, and learn what the dorsal lip has to do with cell differentiation. Once a new life begins to form, a new mother's body undergoes miraculous changes. Once you finish our videos, your mind may do the same.
1. Overview of Animal Reproduction and Development
At this stage in life, you likely know where babies come from. However, did you know that some animals can make clones of themselves and reproduce sexually too? In this lesson, you'll learn more about sexual reproduction and early vertebrate development.
2. Spermatogenesis: How the Male Reproductive System Produces Sperm
In this lesson, you'll learn the series of steps necessary to produce a fully functional sperm cell. You'll also look at the structure of a sperm cell and see how it's equipped to venture forth into new territory.
3. Oogenesis: How the Female Reproductive System Produces Eggs
Did you know that a human female already has all of the oocytes that she will make in her entire life before she is even born? In this lesson, you'll learn how the human body produces an ovum through the process of oogenesis. You'll also learn how polar bodies help to ensure that female gametes are of high quality even though they are not produced in high quantities.
4. Early Embryonic Development: The Morula and Blastula
This lesson on the early stages of mammalian development covers the processes following fertilization, such as cleavage, the morula formation and blastula formation. Watch to learn what the inner cell mass, trophoblast cells and blastocyst are, as well as their functions within embryonic development.
5. Embryo Implantation and Placenta Formation
This lesson will cover the journey the mammalian embryo first makes after it has been fertilized. Learn how maternal blood moves through the embryo, and how the placenta is formed.
6. The Placenta and the Fetus: Structure and Function
Have you ever wondered how a baby eats before it's born or if babies go to the bathroom while still inside their mother? In this lesson, you will learn about the placenta and how it works to ensure a fetus stays well-nourished and healthy before birth.
7. Amniotic Fluid, The Amnion, and the Yolk Sac
From a chick developing inside an egg to a human baby growing in its mother's womb, all developing vertebrates rely on a support system to protect them, feed them, supply them with oxygen, remove wastes, and do much, much more to ensure that the embryo grows and develops into a fully functional organism. In this lesson, you'll learn about the different parts of that support system and some of the things that they do.
8. Gastrulation and the 3 Germ Layers (Ectoderm, Endoderm & Mesoderm)
Gastrulation is a key process in embryonic development - it's how a simple ball of cells begins to grow into a fully functioning being! Watch this lesson to learn about a key process in the development of almost all multicellular organisms.
9. Spemann's Organizer: Controller of Cell Fate
Have you ever wondered how different parts of a developing embryo know what kind of tissue to become? What prevents two heads from developing on the same embryo, or for that matter, what ensures that a head develops at all? A small group of cells called Spemann's organizer determines the fates of the cells around them.
10. Concentration Gradients, Signaling Molecules & Inhibitors in Development
The discovery and characterization of Spemann's organizer was a significant achievement in the field of developmental biology, but this small piece of the dorsal lip is only the tip of the iceberg when it comes to coordinating the differentiation of all of the various tissue types in a growing embryo. In this lesson, you'll learn about concentration gradients and how they can be used to create various combinations of signaling molecules in different parts of the embryo.
11. How Signaling Molecules Control Differentiation
From signaling molecules to transcription factors and gene expression, in this lesson you'll learn what it takes for a cell to differentiate. You'll also learn some of the ways a cell can make sense of different combinations of signaling molecules and how these combinations can be used to guide a cell through the process of differentiation.
12. How Fate Mapping Is Used to Track Cell Development
Over the years, scientists have developed several methods to label and track groups of cells as they develop. These types of experiments are called fate mapping studies. In this lesson, you'll learn the basics of fate mapping and see how technology has allowed scientists to improve fate mapping techniques.
13. Survivorship Curve: Types & Examples
Scientists use a variety of tools to track the sizes of populations. Survivorship curves are one of the tools they use. In this lesson, we will view examples of survivorship curves to determine what they mean.
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Other chapters within the CLEP Biology: Study Guide & Test Prep course
- Scientific Principles
- Review of Inorganic Chemistry For Biologists
- Introduction to Organic Chemistry
- Cell Biology
- How Enzymes Work
- Basics of DNA & RNA
- Process of DNA Replication
- The Transcription and Translation Process
- Basics of Gene Mutations
- Basics of Metabolic Biochemistry
- Overview of Cell Division
- Plant Biology
- Plant Reproduction and Growth
- Physiology I: The Circulatory, Respiratory, Digestive, Excretory, and Musculoskeletal Systems
- Physiology II: The Nervous, Immune, and Endocrine Systems
- Biology of Genetics
- Principles of Ecology
- Speciation & Evolution
- The Origin and History of Life On Earth
- Phylogeny and the Classification of Organisms
- Social Biology
- Analyzing Scientific Data