• 1-22 (autosomes) - related to phenotype

• 23rd pair of homologous chromosomes are the sex chromosomes, determines if ure male or female

• Chromosomes are numbered by size - the chromatids that share the same pattern as another chromatied

• sex cells - 23 pairs of chromosomes(haploid), rest of the body - 46 pairs of chromosomes

• fathers determine the biological sex

Down syndrome - Trisomy #21

Edward syndrome - Trisomy #18wh

How to determine karotype:

• Anmiocentesis: procedure fluid taken from the fetus and tested

Selective Breeding

Selective breeding: method used by farmers to alter the appeareance of crops but selectively picking the most desired traits.

1. aims to improve the features of a species

2. selected the best off] the produced offspring and mate these

3. can produce high resistance yielded crops

4. used in livestock farms with the best species - products of selective breeding

5. the best=most expensive using genetic engineering

6. essential for food consumption, economical purposes etc.

Examples of selective breeding:

• roses are bred for color, shape, scent

• sheep - bred for quality wool and lamb production

• apples - bred for color, taste and texture

• dogs - bred for speed and endurance (cross breeding different breeds of dogs)

• linseed- bred for oil production

Advantages:

• Produces an organisms with right features for a particular function

• more efficient and economically viable process for farming and horticulture(the art and science of growing plants)

Disadvantages:

• reduces biodiversity/gene pool

• genetic variation is decreased to the the decreased variety in alleles and amount of alleles in the population/small gene pool

• failure of adaption from the lack of genetic variation

• lead to unexpected health problems

Process of selective breeding:

1. take the traits of individuals and select the best one

2. picking the best one in every generation

Pedigrees