Genetics Flashcards
Define genetics
the branch of science which studies the way characteristics are passed from one generation to the next
What are hereditary characteristics?
characteristics that are inherited from the parents or grandparents
What are genes?
the basic unit of inheritance
What are the 4 chemicals DNA is made up of?
Adenosine
cytosine
guanine
thymine
What is the position of the gene on the chromosome known as?
gene locus
How many chromosomes does a cat have?
38 or 19 pairs
How many chromosomes does a dog have?
78 or 39 pairs
How many chromosomes does a horse have?
64 or 32 pairs
What are non-sex chromosomes called?
autosomes
What is a homologous pair of chromosomes?
The same chromosome, one from the mother and other from the father
Define alleles
two or more genes that occupy the same locus on the chromosome
Define phenotype
the outward appearance of the animal which is determined by a combination of the animals genetic make-up and the environment
Define genotype
The genetic make-up of the animal
What is Mendals 1st law?
alleles separate to different gametes during meiosis
What is Mendals 2nd law?
alleles of different genes separate at random
What is inbreeding?
breeding from two closely related individuals
What is line breeding?
breeding of animals in the same family who are separated by three or four generations - enables breeders to weed out hereditary faults
What is out breeding?
the mating of unrelated or distantly related animals of the same species. Encourages new characteristics into the line. Reduces the risk of hereditary disease but very unpredictable as the geno and phenotype would differ a lot
define congenital disease
one that is present at birth but may or may not be genetic
define hereditary disease
one which is caused by genes inherited from the parents
