Ch5.1 2TTO

• Biologie
• Middelbare school
• vwo
• Leerjaar 2

Welcome!

During this lesson, we will move towards Chapter 5. You will get a short introduction, an overview of the chapter, and we will discuss the first paragraph.

Lesson goals

• You have an overview of Chapter 5
• You can explain what reproduction is and what its function is
• You can explain what hormones and glands are
• You can explain what the difference is between sexual and asexual reproduction
• You can explain what primary and secondary sexual characteristics are

CHAPTER 5: REPRODUCTION

Paragraphs of chapter 5

1. Reproduction and hormones
2. The male reproductive system
3. The female reproductive system
4. The menstrual cycle
5. Human fertilisation
6. Pregnancy
7. Childbirth
8. Birth control
9. Sexually transmitted infections

Overview of chapter 5

• First, we will go into what reproduction is, and what body parts are involved by reproduction
• Later on, we will discuss how all reproductive processes in our bodies work (menstruation, fertilisation, pregnancy, ...)
• Afterwards, we will discuss how to prevent unwanted pregnancies, and how to keep your reproductive system healthy
• As soon as you have a broad knowledge about the reproductive system, we will go into the more 'cultural' aspects of reproduction

Reproduction = the process by which new individual organisms are produced from their "parents". 

Fertilization = bevruchting

Overview

Please note that we will go into some subjects deeper than the book does, so keep an eye on these lessons so you don't miss a thing!

I will indicate on the slide when there is something that is not in the book.

In between the slides there will be questions that you need to answer, so pay attention to all the slides and videos!

PARAGRAPH 5.1: REPRODUCTION AND HORMONES

Reproduction

• Reproduction (or procreation, breeding) = the biological process by which new individual organisms ("offspring") are produced from their "parents''

Reproduction

Why reproduction?

• Every living thing eventually dies. Organisms need to make more of themselves otherwise there would be no life on Earth at all! 

Who reproduce?

• All living organisms

Reproduction

Two types of reproduction:

1. Sexual reproduction (two 'parents' --> one 'child')
2. Asexual reproduction (one 'parent' --> one 'child')

For more info, see the video on the next slide (ignore the part about chromosomes and genetic variety, we will do that next year)

This is not discussed in the book, but still very important to know!

Humans reproduce

1. Aseksual
2. Seksual

Explain what the difference is between sexual and asexual reproduction

Introduction to Dolly

To get a better understanding of the differences between aseksual and seksual reproduction, there will be some questions about the first cloned sheep ever: Dolly. But first watch the video about Dolly!

Is Dolly born after seksual or aseksual reproduction?

1. Seksual
2. Aseksual

As you just saw: Dolly was created by aseksual reproduction as there was not a recombination of genetic information of 2 'parents'. Normally, sheep reproduce seksual. Explain how they do that and what the difference is with Dolly.

The reproductive system

Contains all the organs needed for an organism to be able to sexually reproduce. This system is regulated by hormones.

Hormones

= regulatory substances that control processes in the body

• They do that by giving signals to organs (messengers)
• Produced by hormone glands from the endocrine system
• Transported by the circulatory system to get them where they need to be
• Effect can have a duration of hours up until months/years

Dutch for glands = klieren

Messengers

Hormones are messengers. However, that was the task of the nervous system, right? The difference: the nervous system is for the fast messages (to help you feel and move), the hormones are for the slower messages (to help you grow and change). 

Match the glands with their functions!

Pituitary gland

Thyroid gland

Adrenal glands

Pancreas

Ovaris and testis

Master gland as it controls several other hormone glands

Regulate the body's metabolic rate

Response to stress

Regulates blood sugar levels

Regulates puberty and produce sex hormones

Sex hormones

• Hormones that work in the reproductive system are called sex hormones. 
• Some of those are different for males and females
• Production of these leads to the differences between male and female bodies
• This production happens in many stages of life!

Stages of life

During life, the body goes through several changes. Some of these changes have to do with sex hormones

Primary sexual characteristics

• During the pregnancy, the sex hormones are responsible for the baby developing male or female reproductive organs.
• The organs that are present at birth are called the primary sexual characteristics. 
• Examples: penis, vagina, prostate, uterus, ...

Secondary sexual characteristics

• When the child reaches puberty, sex hormones are produced to develop the secondary sexual characteristics. 
• These are processes and structures that develop throughout puberty. When someone has developed everything, they have reached the end of puberty
• Examples: menstruation, facial hair, lower voice, ...

Now to test if you understood this..

A few questions!

Are the female ovaries a primary or a secondary sexual characteristic?

1. Primary
2. Secondary

Is the development of pubic hair (click ? for Dutch) a primary or a secondary sexual characteristic?

Pubic hair = schaamhaar

1. Primary
2. Secondary

Difficult question: One of the male secondary sexual characteristics is the development of more muscles. Explain how this can be (mis)used in professional sports in adult men and women.

What do you think would happen if a female person would take male sex hormones for a longer period of time?

Regulation of reproductive system by hormones

The regulatory system is regulated by hormones. Mostly oesterogen (in females) and testosteron (in men). The release of these hormones is controlled by the pituitary gland. During early pregnancy the women also produce progesteron to prepare for the implantation of the embryo in the mucous membranes.

implantation = innesteling

mucous membranes = baarmoederslijmvlies

This is not discussed in the book, but still very important to know!

Oestrogen is responsible for:

1. primary sexual characteristics in females
2. secondary sexual characteristics in females
3. primary sexual characteristics in males
4. primary sexual characteristics in males

Only males produce testosteron?

1. True
2. False

Which gland regulates the production of oestrogen and testosteron?

1. Hypothalamus
2. Pituitary gland (Hypofyse)
3. Testis (teelballen)
4. Ovaries (eierstokken)

Where is oesterogen mainly produced?

1. Hypothalamus
2. Pituitarygland/hypofyse
3. Testis (teelballen)
4. Ovaries (eierstokken)

What does testosteron NOT stimulate?

1. Primary seksual characteristics
2. Secundary seksual characteristics
3. Sperm cell production
4. Puberty in boys

The hormone progesterone is secreted during early pregnancy and prepares the uterus for pregnancy

1. True
2. False

That was it! Homework:

• Take notes of this lesson, as well als everything in the book that we didn't mention here
• Complete questions 1, 2 and 3 from your workbook (page 100 and 101)
• Read paragraph 5.2 and 5.3