Genotype-Phenotype Distinction
Chapter 2
Genotype-phenotype
• Phenotype: an individual's directly observable physical and behavioral characteristics, which are determined by both genetic and environmental factors • Genotype: an individual's genetic makeup
Genes-chromosomes
• Chromosomes: rodlike structures in the cell nucleus that store and transmit genetic information • DNA: are what chromosomes are made out of; long, double-stranded molecule that looks like a twisted ladder, each ladder consists of a specific pair of chemical substances called bases, joined together between two sides • Gene: a segment of DNA along the length of the chromosome
Mitosis-meiosis
• Mitosis: the process of cell duplication, in which each new cell receives an exact copy of the original chromosomes • Meiosis: the process of cell division through which gametes are formed and in which the number of chromosomes in each cell is halved
Sex cells • Gametes: sex cells-sperm and ovum-combine; contains only 23 chromosomes; formed through a cell division (meiosis) • Zygote: when sperm and ovum unite at conception, will have 46 chromosomes • Autosomes: 22 of the 23 pairs of chromosomes are matching pairs • Sex Chromosomes: the twenty-third pair; females: XX males: X; Y is short and carries little genetic material, X is a relatively large chromosome • Fraternal/Dizygotic twins: most common type of multiple birth, resulting from the release and fertilization of two ova • Identical/Monozygotic twins: a zygote that has started to duplicate separates into two clusters of cells that develop into two individuals; same genetic makeup
Dominant-recessive (including chart exercise done in class) • Allele: two forms of each gene occur at the same place on the chromosomes, one inherited from the mother and one from the father • Homozygous: alleles from both parents are alike and displays the inherited trait • Heterozygous: alleles differ and relationships between the alleles determine the trait
Genotype-phenotype
• Phenotype: an individual's directly observable physical and behavioral characteristics, which are determined by both genetic and environmental factors • Genotype: an individual's genetic makeup
Genes-chromosomes
• Chromosomes: rodlike structures in the cell nucleus that store and transmit genetic information • DNA: are what chromosomes are made out of; long, double-stranded molecule that looks like a twisted ladder, each ladder consists of a specific pair of chemical substances called bases, joined together between two sides • Gene: a segment of DNA along the length of the chromosome
Mitosis-meiosis
• Mitosis: the process of cell duplication, in which each new cell receives an exact copy of the original chromosomes • Meiosis: the process of cell division through which gametes are formed and in which the number of chromosomes in each cell is halved
Sex cells • Gametes: sex cells-sperm and ovum-combine; contains only 23 chromosomes; formed through a cell division (meiosis) • Zygote: when sperm and ovum unite at conception, will have 46 chromosomes • Autosomes: 22 of the 23 pairs of chromosomes are matching pairs • Sex Chromosomes: the twenty-third pair; females: XX males: X; Y is short and carries little genetic material, X is a relatively large chromosome • Fraternal/Dizygotic twins: most common type of multiple birth, resulting from the release and fertilization of two ova • Identical/Monozygotic twins: a zygote that has started to duplicate separates into two clusters of cells that develop into two individuals; same genetic makeup
Dominant-recessive (including chart exercise done in class) • Allele: two forms of each gene occur at the same place on the chromosomes, one inherited from the mother and one from the father • Homozygous: alleles from both parents are alike and displays the inherited trait • Heterozygous: alleles differ and relationships between the alleles determine the trait