Asexual and Sexual
• Differences between asexual and sexual reproduction
• What is a chromosome?
• Why do different cells have different numbers of chromosomes?
• Production of offspring that only requires one parent
• Parents and offspring have the same traits
• DNA of the offspring is identical to the parents
• Usually found in unicellular and other simple organisms
What are some examples of organisms that reproduce asexually?
• Production of offspring that requires two parents
What two cells join together in sexual reproduction?
• Parents and offspring can have different traits
• The DNA of the offspring is a combination of DNA from both parents
• Most multicellular organisms reproduce sexually
• Sexual reproduction produces genetically diverse populations
Why is genetic diversity important?
• Structures that contain all the DNA that is passed from parents to offspring during reproduction
• Chromosomes are made of chromatin
• Chromatin is made of tightly wound
• Chromosomes have two parts – chromatids held together by a centromere
Draw and label a diagram of a chromosome below:
• The chromatids are exact copies of each other
Most cells in sexually reproducing organisms have two identical copies of each chromosome
These cells are called diploid cells
What does diploid mean?
The two identical chromosomes are called homologous chromosomes
What does homologous mean?
Sperm and egg cells only contain one copy of each chromosome
These cells are called haploid cells
What does haploid mean?
Why would sperm and egg cells only have one copy of each chromosome?
• Human diploid cells have
46 total chromosomes
How many different chromosomes do human cells have?
How many chromosomes do human sperm and egg cells have?