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.