Genetics - USD #306

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14 Δεκ 2012 (πριν από 4 χρόνια και 6 μήνες)

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Genetics

17.1 Modeling Inheritance


Genetics : the study of the way physical traits are passed from parents to
offspring.



Scenario: An eight
-
year old boy has blue eyes. His mother has blue eyes
and his father has brown eyes. You have been asked to explain to the boy
why he has blue eyes.



Materials: 4 colored objects, 3 of which are the same color


3 Paper cups




With you model:


Explain what the different objects in your model
represent.



Describe or draw your model. Be very specific as to how
it explains the process of inheritance.



A young girl has type AB Blood. Her father has type B
Blood and her mother has type A Blood. Can your model
explain how blood type is passed from parents to child?
How? Be specific.




17.2 Genes and Traits

Using pages 210 & 211 Define the following terms:


Genes


Alleles


Dominant


Recessive


Phenotype


Genotype


Homozygous


Heterozygous


What is the difference between a phenotype and genotype?


A plant with red flowers is bred with a plant with white
flowers


A. if all offspring have red flowers, what does this tell you?


B. if all off spring have pink flowers what does this tell you?


Organisms that reproduce asexually have only one parent,
How would you expect the genotype and phenotype of
asexually produced offspring to compare to the genotype
and phenotype of the parent?

17.3 Rearranging Rice Genes


Read page 212


Complete the procedure on page 213


As a class, we will complete the group analysis.

Punnett

Square


Flower Color


B = pink


B=white


Which trait is dominant?


What is the genotypic ratio?


What is the phenotypic ratio?


Try your own:

B=blue, B=brown

Homozygous blue eyed parent crossed

With a heterogynous brown eyed parent.

17.4 Generation Next: Crossing
the offspring


Read page 214


Complete the procedure on page 215


As a group, answer the questions on page 215


Complete the procedure on page 216


As a group, answer the questions on page 216


Individual analysis
questions are NOT REQUIRED!

18.1 Double Crossing Corn


Law of independent Assortment: genes for different traits are inherited
independently of each other.


Use the FOIL Method to set up your
punnett

square


First, Outside, Inside and Last


P=Pink, p=White


T=Tall, t=short


What would the offspring of two heterozygous pink, heterozygous tall
parents look like?


Read pages 218
-
219


Complete the procedure on page 220.


Each person needs to have a data table


Analysis questions are not required on paper, but need to be discussed in
your group.

18.2 Breeding Rice


Different strains of rice plants grow better and produce larger
yields in different parts of the world. For example, rice plants
that grow well in cool, dry highlands of Bhutan perform poorly
in semi
-
tropical areas prone to flooding, such as parts of
southeast Asia. Different strains of rice also have different
tastes and textures. The best rice to grow in any particular
region is a rice that is resistant to common local diseases,
grows rapidly to give the highest yield in the shortest time, is
suited to the local climate, and has a taste and texture
enjoyed by the residents of the region.

Scenario

Imagine you have discovered two different strains of rice.


Strain #1: has a pleasant aroma and flavor (aromatic) but is easily damaged by
flooding (flood intolerant)

Strain #2: can be submerged under water for up to two weeks, then recover
and grow once the flooding is over (flood tolerant), but has an unpleasant
aroma and flavor (non
-
aromatic)/.


You would like to develop a strain of plants that has the interesting aroma and
flavor of Strain #1 and the flood tolerance of Strain #2.


You breed a plant from Strain 1 with plants from Strain 2 (parent plants) P
Generation, and find that 100% of the offspring (F1 Generation) are flood
tolerant, but non of them have a pleasant aroma and flavor. Assume that:


A stands for the allele for the dominant, non

aromatic trait


a stands for the allele for the recessive, aromatic trait


F stands for the allele for the dominant, flood
-
tolerant trait


f stands for the allele for the recessive, flood
-
intolerant trait



As a class, let’s do the individual analysis on page 222.

Procedure


Complete the procedure on page 223


Each PAIR needs to complete a data chart to turn in.


As a class, we will discuss the questions on page 224.

What does it mean?


Biotechnology & Genetic Engineering


New practice for developing crop strains


Same results as selective breeding, but in a shorter time



Transgenetic


An organism that has been modified through the insertion of genes
from a different species

18.3 Breeding Crops with
Desirable Traits


Read pages 225
-
227, answer the questions on page 227
INDIVIDUALLY,

answer all five questions on paper and turn them in.



Please label your paper 18.3!!

18.4 Cattle Calls


Animal Domestication


Cattle date back to 6500 B.C. identified by remains found in Turkey.


Cattle may have been domesticated as early as 8000 B.C.


However, sheep, goats, pigs and dogs were most likely domesticated
earlier


Cattle have been selectively bred to perform better in one of the three
areas they are used for


Purposes of cattle


Meat


Milk


Labor


Ankole

Watusi


Florida Cracker/
Pineywoods


Better known as the Texas Longhorn

Milking Devon


Ayrshire


Galloway


Senepol


Barzona


Holstein


Shorthorn


Brahman


Maine
-
Anjou


Zebu


1.
Obtain a Material World Book

2.
As a group, select a country other than the US

3.
Follow the procedure on page 229

4.
Answer the group analysis questions, as a group and turn in. Put all
names on it and label it 18.4.


19.1 Genes, Chromosomes and
DNA


Revealing the genetic code has allowed us to alter the characteristics of
plants and animals, usually to increase production

How it’s all Related


Genes are made up of DNA


Chromosomes are long
strands of DNA


Genes are a specific segment
of a chromosome


A genome is all of the genes
of a species together


A review of cellular reproduction

Mitosis


Cells are reproduced through mitosis by copying the DNA that forms
its chromosomes


Replication is the process of making an exact duplication of each
chromosome


Once the two cells divide, they produce daughter cells


Meiosis


Sex cells are formed through Meiosis, producing four sex cells each
having one complete set of single chromosomes



Abnormalities


Errors in this process result in mutations


Read pages 230
-
232 and INDIVIDUALLY answer the questions on page 232,
pleas turn it in.


Then complete the
Karyotyping

Lab

19.3 Fight the Blight

The History of Food
Technolgy

1795

Nicolas
-
Francois
Appert

invents a way to preserve fresh
foods by hearting and sealing them in metal or glass
containers.

This starts the canned food industry.

1800 B.C

People used yeast to make win, beer and leavened
(soft) bread.

This is the first time people use microorganisms to
create new and different foods.

8000 B. C

People decided to live in one place and grow plants as
crops.

They saved the best of their crops to use a seed the
next year.

1914

American Clarence Birdseye invents quick
-
frozen
foods.

This made many fruits, vegetables and meats
available year
-
round.

1865

From experiments on pea plants in a monastery
garden,
Gregor

Mendel researched inheritance.

He concluded that certain unseen particles pass traits
from generation to generation.

1856

Louis Pasteur invents a process of hearting liquids to
destroy unwanted organisms.


This process


pasteurizations
-

is one of the greatest
steps in food safety

1973

Cohen and Boyer move a gene from one organism to
another.

This paves the way for biotechnology improvements.

1953

Watson and Crick define the structure of DNA.

This allows us to understand how cells in all living
things store, duplication and pass genetic information.

1922

Farmers first purchase hybrid seed corn created by
crossbreeding two corn plants.

Hybrid helps account for an increase of nearly 600% in
the U. S. production of corn between 1930 & 1985.


mid 1990’s

The first crops improved through
biotechnology are commercialized

Insect
-
protected cotton and potatoes,
soybeans, canola and cotton with improved
weed control

1990

The US Government approves the first food
product modified by biotechnology.

An enzyme used in cheese making

Why use Biotechnology?


The selective breeding of blight
-
resistant rice took over 10 years and
produced only one new blight
-
resistant variety.


Biotechnology reduces the time it takes to get the desired result, even
though it is not “fast”


With biotechnology you can transfer genes from one species to another,
that would otherwise not be able to be “bred” together.


Researches have transferred animal genes into plants: a gene from a
firefly has been used to create tobacco plants that glow!


Genetic Resistance to Disease


Read the story of the blight
-
resistant gene on page 239. Create a timeline
that shows each step in the process and a summary of what they did.

20.1 The Clone Zone


Should humans continue to research genetic engineering and cloning for
the purpose of increasing food production?


Pros

Cons