Download Selective Breeding

Mind Stretcher- 3/15/17
1.A change in the DNA sequence that can
be harmful, helpful or make no difference
A.Ribosome
B.Messenger RNA
C.Mutation
D.Transfer RNA
Selective Breeding
S7L3. Students will recognize how biological
traits are passed on to successive generations.
c. Recognize that selective breeding can
produce plants or animals with
desired traits
• KNOW: Selective Breeding
–choosing two organisms of the same
species and mating them with the hope
of getting the best qualities of each
parent to show up in the offspring.
–Also called “Artificial Selection”
Selective Breeding: Details
Cross out 1st bullet…
• Used mostly for dogs, cats, other pets,
cattle, and crops.
REMEMBER: Selective breeding crosses
(mates) organisms with desirable traits to
produce offspring that have the traits from
both parents!
Selective Breeding Example A
“Robust” means
STRONG &
HEALTHY!
Tough wild boars mated with friendly meaty pigs
give you robust & meaty pigs for your farm.
Tough Boar + Meaty Pig =
(strong, tough, meaty pig)
Selective Breeding Example B
Brahman cattle:
Good resistance to
heat, but poor beef.
English shorthorn
cattle: Good beef but
poor heat resistance.
Santa Gertrudis cattle
(cross of 2 breeds)
RESULT = good beef
and resistant to heat!
hot weather cow + beefy cow =
(beefy/hot weather cow)
Selective Breeding: Example C
Ancient corn
from Peru
(~4000 yrs old)
Choosing only the best corn plants to use for future
seeds = better crops over time.
Selective Breeding Example D
X
=
little red + big green = BIG RED TOMATO
Advantages
of Selective Breeding
• Might get improved organisms
• Don’t need any special tools or lab
• Can be performed easily by farmers &
breeders
You “SELECT” for traits you
want to “BREED”
Disadvantages
of Selective Breeding
• Undesirable traits from both parents may
appear in the offspring
• Disease can accumulate in the population
– deaf dalmatians, boxers with heart disease, labs
with hip problems, etc.
• Genetic disorders become more prominent
due to Inbreeding (breeding of closely
related family members to increase a
particular trait)
Selective Breeding: Biology for All
https://youtu.be/fHS-OY9XDZc
Bald Chickens!?
https://youtu.be/W4u8xMnr15Q
REVIEW
• Genetic Engineering
– Keep this side blank…we
will complete it soon!
• Selective Breeding
– Process has been around
for thousands of years
– Combines the best traits
of two organisms
– Results in organisms that
have the desirable traits
of their parents
Selectively Breeding Dogs Activity
• Using your completed student sheet from
yesterday, fill in the final “Best in Show”
organizer and turn into the tray!
Some Inherited Traits:
Idea of how to DRAW it:
Hearing
Type of dog ears
(floppy or straight/pointy ears)
Speed
Bark
Length of legs
Trainability or Disposition:
List it somewhere around dog!
(Awards, Thought bubbles, etc.)
Lines around mouth showing noise
level…Or use speech bubble, etc.
• Make sure BOTH “breeder” names are on it!