1. How to Use This Presentation To View the presentation as a slideshow with effects select “View” on the menu bar and click on “Slide Show”, or simply press F5 on the top row of your keyboard. To advance to the next slide click the left mouse button once. From the Chapter screen you can click on any section to go directly to that section’s presentation. Blank or “missing” areas of a slide will remain hidden until the left mouse button is clicked. You may exit the slide show at any time by pressing the Esc key Copyright © by Holt, Rinehart and Winston. All rights reserved.

2. Reproductions and Development Chapter 26 Section 1: Animal Reproduction Section 2: Human Reproduction Section 3: Growth and Development Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

3. Animal Reproduction Section 1 Bellringer Do you know how birds, ants, humans, and sea stars reproduce? Write down any differences that you are aware of in how these animals reproduce. Also write down any differences that you know of in how these animals raise their young. Write your answers in your science journal. Copyright © by Holt, Rinehart and Winston. All rights reserved.

4. Animal Reproduction Section 1 Objectives Distinguish between asexual and sexual reproduction. Explain the difference between external and internal fertilization. Identify the three different types of mammalian reproduction. Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

5. Animal Reproduction Section 1 Asexual Reproduction Identical Copies In asexual reproduction, a single parent has offspring that are genetically identical to the parent. Copyright © by Holt, Rinehart and Winston. All rights reserved. Combining Genes In sexual reproduction, offspring are formed when genetic information from more than one parent combines. Sexual Reproduction End of Slide

6. Animal Reproduction Section 1 Internal and External Fertilization External Fertilization When the sperm fertilizes the eggs outside the female’s body, the process is called external fertilization. Internal Fertilization When the egg and sperm join inside the female’s body, the process is called internal fertilization. Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

7. Animal Reproduction Section 1 Mammals Monotreme Monotremes are mammals that lay eggs. Marsupial Mammals that give birth to partially developed live young are marsupials. Most marsupials have pouches where their young continue to develop after birth. Placental Mammal Placental mammals are nourished inside their mother’s body before birth. Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

8. Human Reproduction Section 2 Bellringer You may have heard of cloning in recent news stories. Do you know what cloning is? If so, write out a definition for cloning. Would cloning be considered asexual or sexual reproduction? Do you think that cloning human beings could be considered as a kind of reproduction? Why or why not? Do you know of any organisms that naturally reproduce by cloning? If so, write out a few examples of these animals. Record your answers in your science journal. Copyright © by Holt, Rinehart and Winston. All rights reserved.

9. Human Reproduction Section 2 Objectives Identify the structures and functions of the male and female reproductive systems. Describe two reproductive system problems. Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

10. Human Reproduction Section 2 The Male Reproductive System Sperm Production The male reproductive system, shown on the next slide, produces sperm and delivers it to the female reproductive system. The testes are a pair of organs that make sperm and testosterone. Testosterone is the main male sex hormone. Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

11. The Male Reproductive System Section 2 Copyright © by Holt, Rinehart and Winston. All rights reserved.

12. Human Reproduction Section 2 The Female Reproductive System The Egg’s Journey The female reproductive system produces eggs, nurtures fertilized eggs (zygotes), and gives birth. During ovulation, an egg is released from an ovary and passes into a fallopian tube. If the egg is fertilized, the resulting zygote enters the uterus. Menstrual Cycle The first day of menstruation, the monthly discharge of blood and tissue from the uterus, is counted as the first day of the menstrual cycle. When menstruation ends, the lining of the uterus thickens. Ovulation occurs on about the 14th day of the cycle. Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

13. The Female Reproductive System Section 2 Copyright © by Holt, Rinehart and Winston. All rights reserved.

14. Human Reproduction Section 2 Multiple Births Twins, Triplets, Quadruplets, and More In every 1,000 births, there are about 30 sets of twins. In the United States, there are about two sets of triplets in every 1,000 births. Births of quintuplets or more happen only once in about 53,000 births. Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

15. Human Reproduction Section 2 Reproductive System Problems STDs Chlamydia, herpes, and hepatitis B are common sexually transmitted diseases. A sexually transmitted disease, or STD, is a disease that can pass from one person to another during sexual contact. Cancer Sometimes, cancer happens in reproductive organs. Cancer is a disease in which cells grow at an uncontrolled rate. Infertility In the United States, about 15% of married couples have difficulty producing offspring. Many of these couples are infertile, or unable to have children. Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

16. Growth and Development Section 3 Bellringer Name the stages of physical development that you have gone through in your life so far. What are the next few stages of development that you will go through? List some physical and social changes that will happen during these next stages. Are you looking forward to these future developmental stages of life? Record your thoughts in your science journal. Copyright © by Holt, Rinehart and Winston. All rights reserved.

17. Growth and Development Section 3 Objectives Summarize the processes of fertilization and implantation. Describe the development of the embryo and the fetus. Identify the stages of human development from birth to death. Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

18. Growth and Development Section 3 From Fertilization to Embryo Development of an Embryo A fertilized egg (zygote) travels down the fallopian tube toward the uterus. Eleven to 12 days after fertilization, the zygote has become a tiny ball of cells called an embryo. The embryo implants itself in the uterus. Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

19. Growth and Development Section 3 From Embryo to Fetus Weeks 1 and 2 Doctors commonly count the time of a woman’s pregnancy as starting from the first day of her last menstrual period. Weeks 3 and 4 In week 3, after fertilization, the zygote moves to the uterus. At the end of week 4, implantation is complete and the woman is pregnant. Weeks 5 to 8 In this stage, the embryo becomes surrounded by a thin membrane called the amnion. The heart, brain, other organs, and blood vessels start to form. Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

20. Growth and Development Section 3 From Embryo to Fetus continued Weeks 9 to 16 At week 9, the fetus may begin to make tiny movements. The fetus grows rapidly during this stage. It doubles, and then triples, its size within a month. Weeks 17 to 24 By week 17, the fetus can make faces. By week 23, the fetus’s movements may be quite vigorous! Weeks 25 to 36 At about 25 or 26 weeks, the fetus’s lungs are well developed. By the 32nd week, the fetus’s eyes are open and perceive light through the mother’s abdominal wall. Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

21. Growth and Development Section 3 Birth Labor Typically, as birth begins, the mother’s uterus begins a series of muscular contractions called labor. Usually, these contractions push the fetus through the mother’s vagina, and the baby is born. Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

22. Growth and Development Section 3 From Birth to Death Infancy to Childhood Generally, infancy is the stage from birth to age 2. Childhood—another period of fast growth—lasts from age 2 to puberty. Adolescence The stage from puberty to adulthood is adolescence. During puberty, a person’s reproductive system becomes mature. Adulthood From about age 20 to age 40, you will be a young adult. Beginning around age 30, changes associated with aging begin. The aging process continues in middle age (between 40 and 65 years old). Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

23. Stages of Human Development Section 3 Copyright © by Holt, Rinehart and Winston. All rights reserved.

24. Reproductions and Development Chapter 26 Concept Map Copyright © by Holt, Rinehart and Winston. All rights reserved. Use the following terms to complete the concept map on the next slide: fragmentation, reproduction, sexual reproduction, internal fertilization, an embryo, zygote, egg, budding, asexual reproduction.

25. Concept Map Chapter 26 Copyright © by Holt, Rinehart and Winston. All rights reserved.

26. Concept Map Chapter 26 Copyright © by Holt, Rinehart and Winston. All rights reserved.