Asexual and Sexual Reproduction

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Asexual and Sexual

Reproduction

Key Concepts and Vocabulary

Key Concepts:

• Differences between asexual and sexual reproduction

• What is a chromosome?

• Why do different cells have different numbers of chromosomes?

Key Vocabulary:

• Asexual

• Sexual

• Chromosome

• Haploid

• Diploid

Asexual Reproduction

• 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?

Types of Asexual Reproduction

Binary fission

Mitosis

Budding

Fragmentation

Types of Asexual Reproduction

Sexual Reproduction

• 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

• Sexual reproduction produces genetically diverse populations

Why is genetic diversity important?

Chromosomes

• 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

DNA

Chromosomes

• 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

Chromosome Numbers

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?

Chromosome Numbers

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 Chromosomes

• 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?

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