Genetics Flashcards
Where are genes found?
On the gene loci of chromosomes
What makes up chromosomes
Chromatin fibres (which are long molecules of DNA)
What are the 2 base pairs?
Guanine and Cytosine
Adenine and Thymine
What is the difference between the diploid and haploid number of chromosomes?
Diploid - paired chromosomes
Haploid - single chromosome
How many (haploid) chromosomes do dogs and cats have?
Dogs = 38 chromosomes Cats = 78 chromosomes
What is the difference between alleles and homologous pairs?
Homologous pairs are two chromosomes paired together, whereas alleles are specific homologous pairs that have identical gene loci.
What are sex-linked genes?
Genes that are located on sex chromosomes
Which chromosomes are bigger?
X
What are sex-limited genes?
Genes that have a characteristic that can only be expressed in one sex (can still be carried by the other)
What happens if a gene is damaged and there is a mis-repair?
- The sequence is so different that the gene is destroyed
2. the gene mutates and codes for the same characteristic in a different way e.g. an extra digit
What is epistasis
When a gene can supress the effects of other unrelated genes located at a different locus
What is a co-dominant gene?
Where both genes are expressed equally e.g. blood type AB
