Science 5 5.1 Animals That Are Born Alive.pptx

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1. Lesson 5.1 Animals That Are Born Alive

2. understand how animals give birth live offspring; and 1 A t the end of this lesson, you should be able to: identify characteristics of an animal that is born alive. 2

3. Among all the different animals in the world, most of the animals born alive are from the group of animals called mammals.

4. Internal and External Fertilization Internal fertilization is fertilization that occurs inside the mother’s body. External fertilization is fertilization that occurs outside the mother’s body. Fertilization

5. Development Inside the Mother The embryo produced by internal fertilization stays inside the mother’s body until birth. The mammal’s embryo is protected by a sac attached to the mother’s body. This sac is called a placenta . . Placenta

6. Advantages of Carrying the Baby Inside the Mother The mother can take care of the developing baby without leaving it unprotected. The mother can also make sure that the developing embryo is supplied with food by eating more. Maternal Care

7. Disadvantages of Carrying the Baby Inside the Mother The mother’s movements can be limited because of the weight of the baby inside it. A mother can carry only a limited number of developing embryo inside its body. Maternal Care

8. Gestation Gestation is another term for pregnancy in animals. Gestation period is the length of time it takes for the embryo to develop inside the mother’s body, until it is born. A pregnant lioness

9. Live Offspring Both mammals and non-mammals can give birth to live offspring. Examples are marsupials (mammals with pouches), mammals with placenta, seahorses, and more. A seahorse with its young

10. Animals are either born alive or hatched from eggs. 1 Reproduction starts with either internal or external fertilization. 2 Animals that are born alive result from internal fertilization and were carried by the parent during the gestation. 3

11. For each animal below, identify whether it is born alive or not. Write B if the animal is born alive, and N if it is not. horse giraffe kangaroo turtle snake

12. What is the advantage and disadvantage of internal fertilization?

13. Slide 8. PregnantLioness by Robin Alasdair Frederick Hutton from Perth, Western Australia is licensed under CC BY 2.0 via Wikimedia Commons .

14. Hackett, Dr. Jay, Dr. Richard Moyer, Dr. Joanne Vasquez, Mulugheta Teferi, M.A., Dinah Zike, M.Ed, Dr. Dorothy Terman, and Dr. Gerald Wheeler. 2013. Science A Closer Look 5. Quezon City: McGraw-Hill Education (Asia) and Phoenix Publishing House. "Marsupial Mammals". 2017. Ucmp.Berkeley.Edu. http://www.ucmp.berkeley.edu/mammal/marsupial/marsupial.html. "Lesson 3 - Gestation Periods - Wildlife Aid Education". 2017. Wildlife Aid Education. http://www.wafeducation.org.uk/teaching-materials/year-5/animals-including-humans-5/lesson-3-gestation-periods/. "Lactation - Marsupials". 2017. Ansci.Illinois.Edu. http://ansci.illinois.edu/static/ansc438/Lactation/marsupials.html . "Rabbit Health: The Amazing (And Scary) Reproductive Potential Of Rabbits". 2017. Bio.Miami.Edu. http://www.bio.miami.edu/hare/scary.html.