T6 B6 1HVTTO

• Biologie
• Middelbare school
• havo, vwo
• Leerjaar 1

B6 Sexual reproduction

• Take off your jacket
  
• Put your things on your desk
  

       Book/Laptop
       Notebook

• Bag on the floor
  
• Read pages 199-202

Lessongoals

• You can explain that both parents add 50% of the DNA in sexual reproduction.
  
• You can describe basic differences between meosis and norma cell division.
  
• You can list and recognize examples of sexual reproduction
  
• You know the difference between internal and external fertilization

Homework U6 B6

Asgmt 1-8, 3c

OR challenge

Asgmt 4-10

All flowers have carpels

1. True
2. False

All stamen make pollen

1. True
2. False

In flowers pollination always happens before fertilization

1. True
2. False

A watermelon originates from 1 ovary

1. True
2. False

By counting seeds in an apple you can determine the amount of fertilizations that happened in the flower.

1. True
2. False

Sexual reproduction

• Fertilization happens
• Needs 2 sex cells
• DNA offspring = 50% father + 50% mother 

in plants:                                   and   

nucleus

egg cell

Asexual reproduction

• Reproction without fertilization or sex cells.
• Part of organism becomes new organism.

• DNA exactly the same

Tubers in potatoes are parts of the stem that can grow into new plants

Bulbs are thickened leaves. Inside the bulb new bulbs grow. These can become plants

Strawberry plants have runners. These stems will form new plants. 2 plants form when the runner is detached

Normal cell division (mitosis)

• Everywhere in the body
• Used in normal cell division and asexual reproduction 
• Daughter cells are copy of parent cell 

Meiosis

• In reproductive organs
• Used to make sex cells, for sexual reproduction
• Daughter cells have 50% of the DNA of the parent cell

Normal cell division (mitosis)

Cell division

First all DNA is copied, then divided. 

Each daughter cell ends up with the same amount of DNA as de parent cell

Daughter cell

1 daughter cell specialises into a specific cell type.

1 daughter cell will become a new parent cell and divide again

chromosome

Chromosome are made of DNA.

Each body cell contains the same amount of DNA

Meiosis

Meiosis

Chromosomes are split, each daughter cell has half of the DNA

sex cell

Daughter cells become sex cells.

Male > pollen grains or sperm

Female > egg cells/ova

Parent cell

These parent cells are found in the reproductive organs of the organism.

Plants > ovule and pollen sacs

Animals > ovaries and testicles

Meiosis and fertilization

Meiosis

Chromosomes are split, each daughter cell has half of the DNA

Fertilization

Two sex cells fuse, creating a fertilized egg cell, containing DNA of both parents

After meiosis

In plants, sex cells can fertilize each other by going trough the steps of pollination (learned in basics 2 and 3)

In animals during sex sperm and egg cells are 'combined' making fertilization happen

Fertilized egg cell

The fertilized egg cell contains the DNA of both parents.

50% of the father and 50% of the mother

Sexual reproduction in animals

Internal fertilization

• Sex cells fuse inside the body 
• Happens in: mammals, birds, insects

External fertilization

• Sex cells fuse in water (outside the body)
• Happens in: fish, amphibians

What you should do: U6 B6

• Pages 199-207 
• Asgmt  1-8, 3c 

OR challenge

•  Asgmt 4-10

Done with the above?

• Work on the next chapter(s)
• Learn for the test 
• Make other homework
• Read a book

Zs = Working in Silence

• No asking questions
• Silent, don't disturb anyone
  
• Stay at your  desk

What you should do: U6 B6

• Pages 199-207
• Asgmt 1-8, 3c

OR challenge

•  Asgmt 4-10

Done with the above?

• Work on the next chapter(s)
• Learn for the test 
• Make other homework
• Read a book

Zw = Working with whispering

• Teacher is available for questions
• Only whisper with the student next to you
• Stay at your  desk