Inheritance D3.2 Flashcards
How is a zygote formed?
male and female gametes fuse, their nuclei join and double the chromosome number
What is inside of the zygote nucleus?
contains two chromosomes of each type and is therefore diploid with two alleles of each gene.
What are hybrids?
crossed
What is self pollination in plants?
grow male and female in the same plant
P-generation
the parental generation or the first-true breeding crossed
F1 generation
the first generation of offspring produced by crossing two true-breeding parents. they are typically heterozygous
F1 generation
crossing individuals from F1. often exhibits 3:1 ratio
Allele
alternate version of a gene that differs by one or a few bases and occupies the same locus on a chromosome
Law of segreation
only one of the two gene copies present in a diploid organism is distributed to each gamete that it makes during meiosis.
Genotype
the genetic makeup of the organism and codes for the phenotype. symbolic representation of a pair of alleles.
Phenotype
observable traits
Phenotypic plasticity
gene expression changes in order to become adapted to specific environmental conditions. it is reversible as alleles remain unchanged.
Phenyletonuria
genetic disease caused by a recessive allele of a gene, mutation of ene on chromosome 12 coding for the enzyme phenylalanine hydrolase. disruptions with neurotransmitters in the brain: mental disorders
Codominance
both alleles are expressed independently in the phenotype and are uniquely recognizable.
Roan
cows with red and white coats
Incomplete dominance
the action of one allele does not completely mask the other
What is codominance and incomplete dominance denoted by?
CW CR
Gene pool
the genes of all the individuals in a sexually reproducing population
What are some characteristics of the gene pool?
- only one copy of an allele can exist on each chromosome - an individual can only inherit two alleles rather than the full number available in the gene pool.
- contains many different alleles of a gene due to existence of multiple alleles caused by SNPs.
Single nucleotide polymorphism
an alternate version of a gene can be created.
- many different versions of a gene exist, there can be multiple alleles of any gene.
- nucleotide change
The existence of more than two phenotypes
some genes dont only have two alleles but three, four, five…
What is the existence of more than two phenotypes dependent on?
dominant/recessive/codominant/etc
What gene codes for the production of glycoproteins in ABO blood groups?
- i
- IA
- IB
Which sex chromosome is larger?
X, therefore Y contains less genes: some are unique to Y some are shared with X