Download Using Crossbreeding and Hybrids

Using Crossbreeding and Hybrids
Next Generation Science/Common Core Standards Addressed:
• MS‐LS2‐1. Analyze and interpret data to provide evidence for the effects of
resource availability on organisms and populations of organisms in an
ecosystem.
• RST.6‐8.1 Cite specific textual evidence to support analysis of science and
technical texts. (MS-LS1-6),(MS-LS2-1),(MS-LS2-4)
• RI.8.8 Trace and evaluate the argument and specific claims in a text,
assessing whether the reasoning is sound and the evidence is relevant and
sufficient to support the claims. (MS-LS2-4)
• WHST.6‐8.1 Write arguments to support claims with clear reasons and
relevant evidence. (MS-LS2-4)
• 6.RP.A.3 Use ratio and rate reasoning to solve real-world and mathematical
problems. (MS-LS2-5)
Bell Work!
• Discuss the importance of improved organisms to agriculture.
• Identify methods used in agriscience to improve organisms.
• Identify breeding systems used in animal science.
• Why are crossbreeding and hybrids important financially?
Terms:
• Hybrid
• Hybrid vigor
• Crossbreed
• Linbreeding
• Heterosis
• Inbreeding
• Genetic
• Manipulation
• Urbanization
Why is improving organisms
important to agriculture?
• Three main factors driving this goal:
• Rising World Population
• Urbanization
• Fewer people in production agriculture
Rising World Population
• Life expectancy continues to rise and
infant mortality rates continue to drop
• All of these people need to eat.
• It is the job of agriculture to make sure
there is enough food produced.
Urbanization
• As the world’s population increases, people need places
to live, work and play.
• The world’s cities continue to grow, swallowing up
more and more land that was used for farming.
• Because of this, producers are expected to produce more
food using less land.
Fewer people in production
agriculture
• Burden of feeding the world on fewer and fewer people.
• Average age of the producer is very high.
2013 – Average American Farmer is 58 yrs. of age.
Average Japanese Farmer is 66 yrs. Of age.
Hybrid seed
• One example of a major breakthrough in
organism improvement occurred in the
1930s. Hybridization of corn began!
• Hybrids produce 25% to 50% greater
yields than traditional corn varieties and
are fairly tolerant to varying soil and
climatic conditions.
Hybrid Livestock
• Another example of organism improvement can be found in the
animal industry.
• Today cattle and hogs can reach market weight several days sooner
using less feed. (Feed Efficiency has improved)
• Cross bred animals grow faster than pure bred parental stock. This is
known as “hybrid vigor”.
What methods are used in agriscience to
improve organisms?
• Two major approaches are used:
• Controlled breeding
• Genetic manipulation.
Controlled breeding
• Breeding plants or animals to
achieve certain characteristics in
the offspring.
• Considered a natural method of
improving plants and animals.
• Scientists control the natural
breeding process.
Kinds of controlled breeding:
• Selection
• Choosing a few parents with the desired traits with
the intent of increasing the amount of desired
qualities in the offspring.
Kinds of controlled breeding:
• Inbreeding
• Breeding offspring of the same parents to each other.
( father x daughter, father x granddaughter etc.)
• Used to produce a new generation without the introduction of any
new genes. Desired result is to compound desirable characteristics.
Hybridization
• Crossing of two different plants or animals
• Combines the traits of different parent strains.
• Many hybrids are not able to reproduce.
Genetic manipulation
• Artificial means of producing desirable traits.
• Genes can be moved from one species to another.
• Gene splicing is the moving of hereditary characteristics from
one organism to another often unrelated organism.
What are the different breeding
systems used in animal science?
•Two basic breeding
systems?
•Inbreeding
•Crossbreeding or
outbreeding
Inbreeding
• Mating of closely related animals.
• Mating of these individuals allows for
the concentration of genes to make
animals more homozygous for all
traits.
Linebreeding
•A specific type of inbreeding is
called linebreeding.
• Linebreeding is the mating of
related animals that are not
immediate family members.
Crossbreeding or outbreeding
• Mating of animals that are not
related.
• The phenomenon of heterosis is often
observed in crossbred animals.
• Heterosis or hybrid vigor, is the
increase in a performance trait that
exceeds the average of the parents.
Review / Summary
• Discuss the importance of improved organisms to agriculture.
• Identify methods used in agriscience to improve organisms.
• Identify breeding systems used in animal science.
The end!