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Punnet Square. http:// www.youtube.com / watch?v = GbhsayzxNoQ. JTPS ( Think pair share) - IBE. Two parents are expecting a baby. They already have a boy. What’s the probability they will have a girl?. J-TPS (Justify –Think Pair Share). THINK. PAIR. SHARE.
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JTPS (Think pair share) - IBE • Two parents are expecting a baby. They already have a boy. What’s the probability they will have a girl?
J-TPS (Justify –Think Pair Share) THINK PAIR SHARE
Punnett squares illustrate genetic crosses • The Punnett square is a grid system for predicting all possible genotypes resulting from a cross.
Punnett squares illustrate genetic crosses. • The Punnett square is a grid system for predicting all possible genotypes resulting from a cross. Homozygous F F F F F F F f F f F f Heterozygous
A monohybrid cross involves one trait. • Monohybrid crosses examine the inheritance of only one specific trait. • Homozygous dominant (FF) X Homozygous recessive (ff) • Outcome: all heterozygous, with dominant phenotype (purple)
Heterozygous (Ff) X Heterozygous Cross (Ff) • Phenotype outcome: 3:1 ratio • 3 purple and 1 white • Genotype outcome: 1:2:1ratio • 1 FF, 2 Ff, 1 ff
A testcross is a cross between an organism with an unknown genotype (FF or Ff) and an organism with the recessive phenotype (ff) • FF • Ff √ ? F ? f
A dihybrid cross involves two traits • Mendel’s dihybridcrosses with heterozygous plants yielded a 9:3:3:1 phenotypic ratio.
A dihybrid cross involves two traits. • Mendel’s dihybrid crosses led to his second law, the law of independent assortment. • The law of independent assortment states that alleles on the same chromosome separate independently of each other during meiosis.
Law of independent assortment • Allele pairs separate independently of each other during gamete formation, or meiosis. That is, different traits appear to be inherited separately
Heredity patterns can be calculated with probability • Probability is the likelihood that something will happen. • Probability predicts an average number of occurrences, not an exact number of occurrences.
Meiosis and 1st Mendel’s law • http://www.sumanasinc.com/webcontent/animations/content/independentassortment.html
JTPS - • Two parents are expecting a baby. They already have a boy. What’s the probability to have a girl?
Review (Vocabulary)
Homologous Chromosomes • Chromosomes that are similar in shape and content and which are donated by each parent
Homozygous • Organisms that have two identical alleles for a particular trait such as TT or tt are said to be homozygous
Heterozygous • Organisms that have two different alleles for the same trait are heterozygous such as Tt
Genotype • Genotype is the genetic makeup of an organism usually represented as; the genotype • Homozygous Dominant (such as TT) • Homozygous Recessive (such tt) • Heterozygous (such as Tt)
Phenotype • Phenotype are the physical (visible) characteristics of an organism such as seen when: • Tall (when the genotype is TT) • Tall (when the genotype is Tt) • Short (when the genotype is tt)
Law of Segregation • Segregation is the separation of alleles during gamete (sex cell) formation.
Law of Independent Assortment • The principle of independent assortment states that genes for different traits can separate (segregate) independently during the formation of gametes.
Crossing Over • Chromosomal crossover (or crossing over) is the process by which two chromosomes pair up and exchange sections of their DNA Video