Transcript Biology - azabielski

13-1 Changing the Living World
Selective Breeding
What is the purpose of selective
breeding?
Slide
1 of 18
Copyright Pearson Prentice Hall
End Show
13-1 Changing the Living World
A New Breed
The tomatoes in your salad and the dog in your
backyard are a result of selective breeding. Over
thousands of years, humans have developed
breeds of animals and plants that have desirable
characteristics. How do breeders predict the
results of crossing individuals with different
traits?
Slide
2 of 18
Copyright Pearson Prentice Hall
End Show
13-1 Changing the Living World
1. Think of two very different breeds of dogs that are familiar
to you. On a sheet of paper, construct a table that has the
following three heads: the name of each of the two dog
breeds, and “Cross-Breed.
2.The rows of the table should be labeled with characteristics
found in both breeds of dogs. Examples might include size,
color, type of coat, intelligence, aggression, and so on.
3.Fill in the column for each of the two dog breeds. In the
column labeled “Cross-Breed,” write in the characteristic you
would expect to see in a cross between the two breeds you
have selected.
Slide
3 of 18
Copyright Pearson Prentice Hall
End Show
13-1 Changing the Living World
1. Think of two very different breeds of dogs that are familiar to you. On a
sheet of paper, construct a table that has the following three heads: the
name of each of the two dog breeds, and “Cross-Breed.
Encourage students to refer only to breeds with which they are
familiar.
2.The rows of the table should be labeled with characteristics found in
both breeds of dogs. Examples might include size, color, type of coat,
intelligence, aggression, and so on.
Additional traits might include shape of ears, shape of muzzle
(pointed or square), or length of legs with respect to body.
3.Fill in the column for each of the two dog breeds. In the column labeled
“Cross-Breed,” write in the characteristic you would expect to see in a
cross between the two breeds you have selected.
Students will likely assume that traits of the cross-breed are
intermediate between those of the two parent breeds.
Slide
4 of 18
Copyright Pearson Prentice Hall
End Show
13-1 Changing the Living World
13–1 Changing the Living World
A.
Selective Breeding
1. Hybridization
B.
2. Inbreeding
Increasing Variation
1. Producing New Kinds of Bacteria
2. Producing New Kinds of Plants
Slide
5 of 18
Copyright Pearson Prentice Hall
End Show
13-1 Changing the Living World
Selective Breeding
Selective Breeding
Selective breeding allows only those organisms
with desired characteristics to produce the next
generation.
Nearly all domestic animals and most crop plants
have been produced by selective breeding.
Slide
6 of 18
Copyright Pearson Prentice Hall
End Show
13-1 Changing the Living World
Selective Breeding
Humans use selective breeding to pass
desired traits on to the next generation
of organisms.
Slide
7 of 18
Copyright Pearson Prentice Hall
End Show
13-1 Changing the Living World
Selective Breeding
Hybridization
Hybridization is the crossing of dissimilar
individuals to bring together the best of both
organisms.
Hybrids, the individuals produced by such
crosses, are often hardier than either of the
parents. (Hybrid Vigor)
Slide
8 of 18
Copyright Pearson Prentice Hall
End Show
13-1 Changing the Living World
Selective Breeding
Inbreeding
Inbreeding is the continued breeding of
individuals with similar characteristics.
Inbreeding helps to ensure that the characteristics
that make each breed unique will be preserved.
Serious genetic problems can result from
excessive inbreeding.
Slide
9 of 18
Copyright Pearson Prentice Hall
End Show
13-1 Changing the Living World
Increasing Variation
Increasing Variation
Why might breeders try to induce
mutations?
Slide
10 of 18
Copyright Pearson Prentice Hall
End Show
13-1 Changing the Living World
Increasing Variation
Breeders increase the genetic variation
in a population by inducing mutations.
Slide
11 of 18
Copyright Pearson Prentice Hall
End Show
13-1 Changing the Living World
Increasing Variation
Mutations occur spontaneously, but breeders can
increase the mutation rate by using radiation and
chemicals.
Breeders can often produce a few mutants with
desirable characteristics that are not found in the
original population.
Slide
12 of 18
Copyright Pearson Prentice Hall
End Show
13-1 Changing the Living World
Increasing Variation
Producing New Kinds of Bacteria
Introducing mutations has allowed scientists to
develop hundreds of useful bacterial strains,
including bacteria that can clean up oil spills.
Slide
13 of 18
Copyright Pearson Prentice Hall
End Show
13-1 Changing the Living World
Increasing Variation
Producing New Kinds of Plants
Mutations in some plant cells produce cells that
have double or triple the normal number of
chromosomes.
This condition, known as polyploidy, produces new
species of plants that are often larger and stronger
than their diploid relatives.
Polyploidy in animals is usually fatal.
Slide
14 of 18
Copyright Pearson Prentice Hall
End Show
13-1 Changing the Living World
Concept Map
Section 13-1
Selective
Breeding
consists of
Inbreeding
Hybridization
which crosses
which crosses
Similar
organisms
Dissimilar
organisms
for
example
for
example
Organism
breed A
Organism
breed B
Organism
breed A
which
which
Retains desired
characteristics
Combines desired
characteristics
Slide
15 of 18
Copyright Pearson Prentice Hall
End Show
13-1
Click to Launch:
Continue to:
- or -
Slide
16 of 18
End Show
Copyright Pearson Prentice Hall
13-1
The usual function of selective breeding is to
produce organisms that
a. are better suited to their natural environment.
b. have characteristics useful to humans.
c. can compete with other members of the
species that are not selected.
d. are genetically identical.
Slide
17 of 18
End Show
Copyright Pearson Prentice Hall
13-1
Crossing a plant that has good diseaseresistance with a plant that has a good foodproducing capacity is an example of
a. inbreeding.
b. hybridization.
c. polyploidy.
d. crossing over.
Slide
18 of 18
End Show
Copyright Pearson Prentice Hall
13-1
New species of plants that are larger and
stronger are a result of
a. monoploidy.
b. diploidy.
c. polyploidy.
d. triploidy.
Slide
19 of 18
End Show
Copyright Pearson Prentice Hall
13-1
The function of inbreeding is to produce
organisms that
a. are more genetically diverse.
b. are much healthier.
c. are genetically similar.
d. will not have mutations.
Slide
20 of 18
End Show
Copyright Pearson Prentice Hall
13-1
Increasing variation by inducing mutations is
particularly useful with
a. animals.
b. bacteria.
c. plants.
d. fungi.
Slide
21 of 18
End Show
Copyright Pearson Prentice Hall