(REP) Reproduction Module Overview

Reproduction Module Overview

Which came first, the chicken or the egg? We may not know the definite answer to this age-old riddle; but scientists can explain how a baby chick is formed. A baby chick is created when the male sperm cell and female ovum meet and combine to form a fertilized egg. This is called sexual reproduction, also known as meiosis. In this module, you will also learn how a new organism is made from asexually reproducing organisms, referred to as mitosis. We will see how it is possible to have cells produced that are exactly like the original cell and how the process of mitosis maintains life for both asexually and sexually reproducing organisms. There are many differences and similarities in mitosis and meiosis, and soon, you will be able to identify many of each. We will look at how scientists are genetically modifying organisms to change traits and study both the pros and cons of these genetic modifications.

 

Essential Questions

  • How do asexual organisms reproduce?
  • How do organisms create cells that will result in an offspring with traits from both parents?
  • How is sexual reproduction an advantage?
  • In what ways are the nuclear cell divisions during mitosis and meiosis similar and how are they different?
  • What is the purpose of mitosis and meiosis?
  • How can selective breeding change future generations of offspring?

 

Key Terms

  1. Reproduction - The process by which organisms produce offspring.
  2. Binary fission - A type of reproduction in which bacteria cells divide to produce cells that are identical to the original cell.
  3. Budding - A type of asexual reproduction in which a part of an organism breaks off and becomes a new organism.
  4. Gamete - A cell that determines the sex of an organism, a sperm or egg.
  5. Mutation - A change in a gene.
  6. Sex linked trait - A trait that is determined by the sex chromosomes of an organism.
  7. Selective breeding - The process of breeding plants and animals so that a desirable trait is expressed in future generations.
  8. Genetic engineering - The process of transferring genes from one organism to another to produce a desirable trait.
  9. Diploid - Having a pair of each type of chromosome, so that the basic chromosome number is doubled.
  10. Haploid - Having a single set of chromosomes.
  11. Meiosis - The process of cell division in sexually reproducing organisms that reduces the number of chromosomes in reproductive cells from diploid to haploid, leading to the production of gametes in animals and spores in plants.
  12. Mitosis - The process in cell division by which the nucleus divides, typically consisting of four stages, prophase, metaphase, anaphase, and telophase, and normally resulting in two new nuclei, each of which contains a complete copy of the parental chromosomes.
  13. Autosome - A chromosome that is not a sex chromosome.
  14. Sex chromosomes - Either of a pair of chromosomes, usually designated X or Y, in the germ cells of most animals and some plants, that combine to determine the sex and sex-linked characteristics of an individual, with XX resulting in a female and XY in a male in mammals.
  15. Homologous chromosome - A pair of chromosomes, one inherited from each parent, that have corresponding gene sequences and that pair during meiosis.
  16. Ovum - The female reproductive cell or gamete of animals; egg.
  17. Oogenesis - The formation, development, and maturation of an ovum.
  18. Spermatogenesis - Formation and development of spermatozoa by meiosis and spermiogenesis.
  19. Trisomy - The condition of having three copies of a given chromosome in each somatic cell rather than the normal number of two.
  20. Monosomy - A chromosome having no homologue, especially an unpaired X-chromosome.
  21. Karyotype - The characterization of the chromosomal complement of an individual or a species, including number, form, and size of the chromosomes.

 

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