Chromosomal inheritance

Question 2

what is sex limited traits

Answer 2

only males have a phenotype even if both males and females have the allels

Question 3

what is the exception to mendelian inheritance

Answer 3

pleiotropy- disorders where multiple organ systems are affected (polled intersex goats)
avoid homozygous polled - females are intersex and males are sterile

Question 4

what is cytogenetics

Answer 4

the study of chromosomes
multiple malformations
fertility problems
phylogeny/evolution
sexing birds

Question 5

how do you determine the type of chromosome, what are the 4 types?

Answer 5

the centromere placement
telocentric (not in humans)
acrocentric
subetacentric
metacentric

Question 6

what is a karyotype

Answer 6

arrange by size and decending order numbered
sex chromosomes last XY - male mammals
ZW female birds
short arm up ( p for petite)
grouped by centromere placement

Question 7

how do you sex birds

Answer 7

now done with DNA
BUT MANY michromosoems
6-9 paris of macrochromosomes
including sex

Question 8

what is the nomenclature?

Answer 8

1. total number of chromosomes
2. sex
3. special findings (+ or -)
   ex. 78,XX(normal bitch)
   65,XY, +15 (abnormal colt fetus)

Question 9

what is the origin of chromosome anomalies?

Answer 9

• many chromosome anomalies arise (de novo) during meiosis of one of the oarents
• others arise through mismatching of homologues during meiosis
  can also occur in a error in cell divsions

Question 10

how do chromosomes divide?

Answer 10

mitosis (exact duplication of somatic cells
dna replicates
chromatids separate
results in 2 diploid cells
meiosis (reduction division - in gametes
Meiosis 1
replicates
homologous pair (crossing over)
chromosomes reparate
results in 2 haplois cells
Meiosis II
chromatids separate
results in 4 haploid gametes