genetics week 2 lpa 2013-2014 standard 4 objective 2
TRANSCRIPT
GeneticsWeek 2
LPA 2013-2014Standard 4Objective 2
Monday Objective
• I will explain the phases of meiosis.
Bell work
• Work with your table partner to find the complete and correct answers to questions #1-7 on page 198.
Review Meiosis
• Draw the phases of Meiosis (with the teacher).
• Use the slips of colored paper and the large paper to model Meiosis. – Large paper = nucleus– Desk = cell– Colored paper = chromosomes
Review Fertilization
Egg + Sperm = Zygote
N N 2N
Homework
• Read pages 199-207.
Tuesday Objective
• I will explain how Mendel’s laws of segregation and independent assortment affect genetic inheritance.
Vocabulary
• Create new flashcards for the following terms:– Genetics– Heredity– Law of Segregation– Law of Independent Assortment
Vocabulary Review
• Review the definitions for each term below:– Gene– Allele– Dominant– Recessive– Genotype– Phenotype
Reading Questions
• What questions do you have after your reading last night?
Heredity
• The passing of ________________ from parent to offspring is called ______________.
• The study of heredity in ____________ is called ____________.
• __________ ___________ is the “Father of modern _____________.”
Blending Inheritance Theory
• During Mendel’s time, the Blending Inheritance Theory was dominant.
• This theory states that _____________ were a “mix” of their ___________.
Mendel’s initial observations:
1. Plants sometimes had offspring that were not exactly like their ____________ nor were they a _______ of their parents.
2. Certain traits ______________ after disappearing in an earlier ____________.
Mendel’s experiments:
• Subject = peas (fast growing and available in many varieties)
• Study seven characteristics of pea plants:– Flower color -- Stem length– Flower position on stem -- Pod shape– Pod color -- Seed shape– Seed color
Mendel’s Experiment
• A ________ is a heritable variation of a characteristic.
• Each trait Mendel studied occurred in _______ contrasting traits.– Short stem vs tall stem– See table at top of page 201
Mendel’s Experiment
• Cross-pollination: Mendel removed the anthers of the flowers in a group and dusted the stigma with stamen from a different group.
• Review the diagram on page 202.
• Monohybrid cross = a cross in which only one characteristic is examined
Mendel’s results
• See data table at bottom of page 203.
• A __________ is a unit of heredity.
Mendel’s Theory of Heredity
1. There are different versions of ______ which account for variations in ____________.
a) Different versions of genes are called __________.
2. When two different _______ are inherited together, ________ may be expressed, while the effect of the other may be “________.”
a) Dominant vs recessive alleles
Mendel’s Theory of Heredity
3. For each _____________, an organism inherits ______ alleles, one from each __________.
4. When __________ are formed, the two alleles of each gene are separated. During __________, each gamete receives _______ allele for each trait. During fertilization, ________ fuse and the zygote contains ________ alleles for each trait.
Law of Segregation
• A ________ of alleles is __________, or segregated, during the formation of __________.
• During __________, homologous chromosomes are randomly __________. Each resulting _______ has an equal probability of receiving either of the two _________.
Mendel’s Second Experiment
• Dihybrid cross = a testcross in which the ___________ of _______ characteristics is tracked at the same time.
• Conclusion = _______________ are inherited independently of each other.
Law of Independent Assortment
• The ___________ of one trait will not affect the inheritance of another.
• Modern Discovery: – Linked genes are genes that are close together on
a chromosome and are packaged into the gametes _____________.
Allele Combinations
• Homozygous Dominant:– Both _______ are dominant (and capitalized)
• Homozygous Recessive:– Both _______ are recessive (and lowercase)
• Heterozygous:– One _________ allele and one __________ allele
Homework
• Complete questions #1-8 on page 207 of your textbook.
• Read pages 208-210.
Wednesday Objective
• I will describe biotechnology that presents ethical issues.
Bell work
• Complete questions #9-14 on page 207 of your textbook.
Quiz
• C =NO communication except with the teacher.• H =Raise your hand and wait to speak.• A =Take the test. Answer every question.• M =Do not get out of your seat or into your bags.• P =Finish the test. When you finish, begin
working on questions #1-5 on page 210.
Questions
• Review questions #1-5 on page 210.
Homework
• Read pages 211-221 in your textbook.
Thursday Objective
• Review Cells and Genes.
• Bill Nye Videos:– Inside the living cells– Genes
• (7th Period has an assembly)
Friday Objective
• I will demonstrate how to predict genotypes and phenotypes.
Vocabulary
• Create new flashcards for the following terms:– Punnett square– Testcross– Heterozygous– Homozygous– Pedigree– Sex-linked trait– Polygenic trait
Reading Questions
• What questions do you have after your reading last night?
Punnett squares
• A Punnett square is a ___________ that helps predict the probable ___________ of alleles in different crosses.
F fFf
Punnett square practice
1. Parents = one purple flower (homozygous) and one white flower. Purple color is dominant.
2. Parents = one purple flower (heterozygous) and one white flower.
Pedigree Charts
• A pedigree is a ___________ that shows the ___________ of a trait over several ______________.
• Pedigrees are commonly used to track genetic __________ and _____-_______ traits.
Sex-linked Traits
• Sex-linked traits have alleles located on the sex ______________ (X or Y).
• There are more ______-linked traits than there are _____ - linked traits.
• Most sex-linked traits are _____________.
Punnett square & Pedigrees
• Complete the practice at the top of page 217.
Non-Mendelian Modes of Inheritance
• Codominance = both traits appear in a ____________ offspring. Neither allele is completely _____________ nor __________.
• Incomplete Dominance = the phenotype of the offspring is somewhere in between the _____________ of both parents. A completely ____________ allele does not occur.
Non-Mendelian Modes of Inheritance
• Polygenic traits = traits that are affected by more than one _________.– Eye color– Skin color– Blood type
Homework
• Complete questions #1-7 on page 221.