Chapter 3- Inheritance Flashcards
What are gametes ?
Haploid so contain one allele of each gene
What does the fusion of gametes result in?
In diploid zygote with two alleles of each gene that may be the same allele or different alleles
What are the three alleles for ABO blood groups?
I^ A
I ^ B
i
What is segregation?
Separation of alleles into different nuclei - the two alleles of each gene separate into different haploid daughter nuclei during meiosis
What can alleles be?
Dominant, recessive or co-dominant
What are dominant and recessive alleles?
Recessive alleles are only shown id the dominant allele is not present
What is a co-dominant allele
Where both alleles have an affect of the phenotype characteristic of the organism
Ex of co-dominance
Flower colour in Mirabilis Jalapa - red flower mixed with white flowers offspring have pink flower
Definition of genotype?
Symbolic representation of a pair of alleles possessed by an organism
What is a phenotype?
The set of observable characteristics resulting from the interaction of genotype
What does genotype I^A I^A five? What does I^B I^B give?
What does i i give?
What does I^A I^B give?
1) blood group A
2) blood group B
3) blood group O
4) blood group AB - co dominant
Antigen A has what type of antibodies?
What type of blood can’t it have?
Antibodies b and can’t have b or ab blood but can O or A blood
Antigen b what type of antibodies does It have?
What type of blood can’t it have?
Has anti- a antibodies and can’t have a or ab blood but can have b or o blood
WHat type of antibodies does antigen AB have?
What type of blood can’t it have?
Doesn’t have antigens but can have any blood type- universal recipient
What types of antibodies has A and B?
What type of blood can it only have?
Has both A and B antibodies and can only have O blood in it- universal donor
Define test cross
Testing a suspected heterozygous by crossing it with a homozygous recessive
What are many genetic diseases in humans caused by?
Due to recessive alleles of Autosomal genes
What are other causes of genetic disease?
Some genetic diseases are sex-linked and some are due to dominant or xo-dominant alleles
What is an example of a disease caused by recessive alleles?
Cystic fibrosis
What is an example of a disease caused by a dominant allele?
Hunting tons disease
What is an example of co-dominant allele?
Sickle-cell anaemia- HB^A and HB^S has some characteristics of sickle cell anaemia without having the disease- resistance to malaria
What is sex linkage?
Any genetic trait whose allele has its logs on the X chromosome
What is cystic fibrosis? What are its consequences?
It is a recessive allele that results in chloride channels being produced that do not function properly- causes production of abnormally thick mucus which builds up in lungs causing infections
What is huntingtin disease?
Dominant allele of the HTT gene- causes degenerative changes in be brain - changes to behaviour, thinking and emotions become increasingly severe - life expectancy is about 20 years after symptoms
