selective breeding

Question 1

why do people do it

Answer 1

so they can improve plants and animals by selecting and breeding only those that have desired characteristics.

has resulted in significant evolutionary changes in certain organisms.

Question 2

procedure
1. identification

Answer 2

decide which characteristics are important

choose parents that show these characteristics.

Question 3

procedure
2. selection

Answer 3

select the best offspring from parents to brees the next generation. (Observable traits like size, shape, growth rate, or taste)

marker assisted selection can be used to screen individuals for the presence of genetic markers commonly associated with desirable/ undesirable traits

Question 4

procedure
3. breeding

Answer 4

1. in animals , artificial insemination is one technique used.
   - involves transferring semen from a male into uterus of a female animal
   - in vitro fertilisation is carried out, embryos are screened and selected. embryos get transferred into uterus of surrogate female.
2. in plants (mendel) you contorl the transfer of pollen from the flowers of one plant to another.

Question 5

benefits

Answer 5

varieties may be economically important, by producing more or better quality food
better able to fight off pests- pest resistant
more fit and stronger animals, etc.

selective breeding can add new genetic varieties to species.
no safety issues to manage under most circumstances.
can help to eliminate problematic diseases
we have a choice of desirable characteristics

Question 6

concerns

Answer 6

reduced genetic variation can lead to attack by specific insects or disease,

animal rights concerns because they cannot select their own breeding partners

rare disease genes can be unknowingly selected as part of a positive trait, leading to problems with specific organisms, eg a high percentage of Dalmatian dogs are deaf

seen as unnatural
can create physical problems in specific organisms