Reproduction

• Sexual reproduction is the joining (fusion) of male and female gametes.
• Meiosis is involved in sexual reproduction.
• Mitosis is involved in asexual reproduction.
• Meiosis is cell division that produces four daughter cells (gametes), each with a single set of chromosomes.
• XX is the female sex chromosomes for humans.
• XY is the male sex chromosomes for humans.
• Male gametes in plants are called pollen.
• Female gametes in plants are called ovules.
• DNA is the genetic material in cells.
• The structure of DNA is two complementary strands forming a double helix.
• A gene is a small section of DNA that codes for a particular amino acid sequence to make a specific protein.
• Alleles are different forms of the same gene.
• A recessive allele is an allele that need to be present twice to be expressed.
• A dominant allele is an allele that is always expressed.
• A genome is the entire genetic material of an organism.
• Homozygous means two of the same alleles present in an organism.
• Heterozygous is two different alleles present in an organism.
• A dominant allele causes polydactyly.
• A recessive allele causes cystic fibrosis.
• Normal human body cells have 23 pairs of chromosomes.
• Studying the human genome is important because:

  Search for genes that are linked to diseases

  Understanding and treating inherited disorders

  Tracing past human migration