D3.2 Inheritance Flashcards
Through which process a haploid gametes are produced?
meiosis
Diploid zygote?
Male and female haploid gametes fused together
Autosome
the other nonsex chromosomes
Homologous pairs
2 chromosomes (one from mom and one from dad) that have the same genes in the same location but possibly different alleles
Allele
different version of a gene
What is genotype?
combination of alleles
Show homozygous recessive in letters
aa
Show homozygous dominant in letters
AA
Show heterozygous in letters
Aa
What is phenotype?
observable traits of an organism that result from genotype and environmental factors
What is phenotypic plasticity?
reversible changes in phenotype due to changing patterns in gene expression (e.g. skin darkening from light exposure)
Phenylketonuria
genetic disease where the mutation causes the gene to change to a recessive allele that codes for an enzyme
What is SNP (single nucleotide polymorphism?
most common variation in humans caused by change in single nucleotide, they can result in many different alleles for a single gene
Types of alleles for blood groups
type A, type B and type O
Which blood group alleles are co-dominant?
type A&B
Which blood group alleles are recessive?
type O
On which chromosome is allele for blood type found and what is the gene?
On chromosome 9 and ABO gene
Codominance
two alleles are both expressed equally (e.g. blood type AB)
Incomplete dominance
phenotype that is somewhere between dominant and recessive allele (e.g. pink flower from white and red parent)
How haemophilia is inherited? (4 points)
-sex-linked recessive disorder
-only females are carriers (one H and one h on x)
-mostly males can be sick
-it is found on x chromosome
Discrete variation
controlled by a single gene, can’t be influenced by the environment, defined categories (nothing in the middle) e.g. blood type (either A, B, AB or O)
Continuous variation
controlled by multiple genes, many phenotypes, influenced by environment, e.g. skin colour
Gene pool
all of the genes in a population
Are sex chromosomes homologous?
no
