5.3

• Biologie
• Middelbare school
• vwo
• Leerjaar 2

Lesson goals

• You can explain what the difference is between sexual and asexual reproduction.
• You can explain the reason you do not show all characteristics of both your parents.
• You can describe the production of gametes.

Reproduction

Two types of reproduction:

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

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!

Sexual vs asexual

Two types of reproduction:

1. Sexual reproduction: more genotypes--->better chances of surviving changing environments. Downside is a possible 'worse' genotype for current environment.
2. Asexual reproduction: very quick reproduction, when environment is suitable. however, changing environment can kill most of the population.

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!

Now to test if you understood this..

A few questions!

Explain what the difference is between sexual and asexual reproduction!

In changing environments, which is better for a species?

1. Sexual reproduction
2. Asexual reproduction

Production of sex cells

-Body cells: pairs of chromosomes (23 pairs).

-Sex cells/gametes: 1 of a pair of chromosomes goes into 1 cell, the other in another cell.

-Crossing-over: parts of chromosomes switch sides.

Geslachtsmoedercel=cell of ovary, producing egg cells

A skin cell of a certain species contains 12 pairs of chromosomes. How many chromosomes does an gamete of this species contain?

1. 6
2. 24
3. 48
4. 12

Exercises basics 5.3

-Do ex 9 + 10