2TTO Ch 5.5

• Biologie
• Middelbare school
• vwo
• Leerjaar 2

Chapter 5.5 fertilisation

Planning

• Lesson goals
• Review question about the previous lessons
• Videos and explanation + inbetween questions in Lessonup 
• For some of you: time to already make the homework
• Time to ask questions to the teacher
• End of class + homework for next week

Lesson goals

At the end of this lesson you know: 

• How human fertilisation works
• What the difference is between fraternal twins and identical twins

Which system regulates hormones?

1. Reproductive system
2. Endocrine system
3. Nervous system
4. Digestive system

Which gland produces hormones to start the production of reproductive cells?

1. Pituitary gland
2. Ovaries
3. Hypothalamus
4. Thyroid gland

Which of the following is not a part of the male reproductive system

1. Penis
2. Testes
3. Uterus
4. Scotum

In which part of the female reproductive system do the egg cells develop?

1. Fallopian tube/Oviduct
2. Ovaries
3. Uterus
4. Vagina

In which part of the female reproductive system does the fertilised egg cell grow into a baby?

1. Fallopian tube/Oviduct
2. Ovaries
3. Uterus
4. Vagina

What regulates the menstrual cycle?

1. Enzymes
2. Hormones
3. Menopause
4. Blood flow

Link the hormone to the function! 

Finishing the uterus lining

Developing the egg

Development of uterus lining

Causing ovulation

Oestrogen

Progesterone

FSH

LH

Human fertilisation

• Fertilisation = the union of a human egg and sperm cell
• The result of fertilisation is a fertilised egg cell, which contains the hereditary information from the male (via the sperm cell) and the female (via the egg cell)
• When one sperm cell succesfully entered the egg cell, than the membrane of the egg call undergoes changes so no other sperm cell is able to enter the egg cell anymore

Fertilisation = bevruchting

Fertilised egg

• A fertilised egg cell is called a zygote
  
• A zygote divides many times, creating a lot of cells containing the same hereditary information
• The zygote (containing many cells) eventually implant in the uterus lining

What is fertilisation?

1. The release of the egg cell from the ovaries
2. The dividing of the zygote
3. Implantation of the zygote into the uterus wall
4. The union of an egg cell and sperm cell

The ovaries release a(n) ... egg

1. Fertilised
2. Unfertilised

The inner lining of the uterus is released when an egg is fertilised

1. True
2. False

A zygote contains the chromosomes (genetic information) of the male and the female

1. True
2. False

Twins

• Sometimes two egg cells ovulate from the ovaries at the same time -> two egg cells may be fertilised -> two different zygotes -> fraternal twins
• One egg cell ovulate from the ovary -> one egg cell may be fertilised -> sometimes the zygote divide into two different groups of cells -> identical twins

Fraternal twins = Twee-eiige tweeling

Identical twins = Een-eiige tweeling

What is the difference between fraternal twins and identical twins?

What happens with the inner lining of the uterus when an egg cell is fertilised vs when an egg cell is not?

Lets work

• This was a very short overview of the human fertilisation. Write down any questions you might have in the next slide of this LessonUp
• Start making your homework (exercise 17, 18, 19, 20, 21, 22, and 24)

Ask any questions here!