VOCABULARY UNIT 1 1. SEXUAL REPRODUCTION: a type of reproduction in which the genetic material from two different cells combine, producing an offspring. 2. EGG: the female sex cell. 3. SPERM: the male sex cell. 4. FERTILIZATION: the process in which an egg and sperm cell join together. 5. ZYGOTE: a new cell formed when an egg and a sperm join together. 6. DIPLOID: cells that have pairs of chromosomes. 7. HAPLOID: cells that have only one chromosome from each pair of parent cells. 8. GENETIC VARIATION: differences in the DNA sequence in a population’s genes, which makes them different. 9. HOMOLOGOUS CHROMOSOMES: pairs of chromosomes that have genes for the same traits arranged in the same order. 10. MEIOSIS: the process in which one diploid cell forms four haploid cells, or sex cells. 11. MITOSIS: cell division that results in 2 daughter cells, each having the same number of chromosomes as the parent cell. 12. SOMATIC CELL: any cell of a living organism other than the reproductive cells. 13. DNA: deoxyribonucleic acid, a self-replicating material which is the carrier of genetic information in nearly all lifeforms. 14. SELECTIVE BREEDING: the process of humans selecting organisms to breed together for desired traits. 15. ASEXUAL REPRODUCTION: a type of reproduction in which one parent organism produces offspring without meiosis or fertilization. 16. FISSION: cell division in prokaryotes that forms two genetically identical cells. 17. BUDDING: the process in which a new organism grows by mitosis on the body of its parent. 18. PROKARYOTIC CELL: a unicellular organism which does not contain a nucleus. 19. EUKARYOTIC CELL: a cell which has a nucleus enclosed within membranes. 20. REGENERATION: a type of asexual reproduction where an offspring grows from a piece of its parent. 21. VEGETATIVE REPRODUCTION: a form of asexual reproduction in which offspring grow from a part of a parent plant. 22. CLONING: a type of asexual reproduction performed in a laboratory that produces identical individuals. 23. TISSUE CULTURE: the process or technique of making body tissue grow in a lab culture. 24. PARTHENOGENESIS: reproduction from an ovum (egg) without fertilization.