Unit 3 Part 4 Flashcards
D3.2 Inheritance
What is diploid?
Used to describe a nucleus that has chromosomes organized into pairs of homologous chromosomes
What is a heterozygote?
An organism that possesses one dominant allele and one recessive allele (ex. Tt)
What is a monohybrid cross?
When parents have different alleles and it shows the results for only one trait
What does homozygous dominant mean?
Both alleles are dominant
What does homozygous recessive mean?
Both alleles are recessive
What is the first filial generation?
First generation produced by a cross
What is self pollination?
When a plant’s polen lands on flowers it has produced itself, this can result in self-fertilization
What can farmers do when they want plants with the same characteristics as previous generations?
They can use self pollination techniques
What can farmers do when they want plants with new characteristics not seen before?
They can use cross pollination techniques
What is a gene?
A DNA sequence that codes for a protein that will give an organism a specific trait
What is a genotype?
The symbolic representation of the pair of alleles possessed by an organism (ex. BB, Bb, bb)
What is homozygous?
Having two identical alleles of a gene
What is heterozygous?
Having two different alleles of a gene
What is a carrier?
An individual who has a recessive allele of a gene that dies not have an effect on phenotype
What is a dominant allele?
Allele that has the same effect on the phenotype whether it is paired w/same allele or not
- Always expressed in phenotype
What is a recessive allele?
Allele that has an effect on the phenotype only when no dom allele is present to mask it
What are codominant alleles?
Pairs of alleles that both effect phenotype when present in a heterozygote
What is phenotypic plasticity?
An organism’s ability to express its phenotype differently depending on the environment
Phenological?
Cyclical events like seasonal food availability
What type of changes can phenotypic plasticity generate?
Can generate changes in physiology, morphology, behavior, or phenology
How can two healthy parents create a child w/ a genetic disease?
Disease is caused by recessive alleles so both parents must be carriers of the version of gene that causes the disease
How is phenylketonuria (PKU) caused?
Caused by mutations in the autosomal PAH gene that results in low levels of enzyme phenylalanine hydroxylase
What are autosomal recessive diseases?
Diseases that are caused by recessive alleles and their locus gene is found on one of 1st 22 pairs of chromosomes but on sex chromosomes x or y
When does single - nucleotide polymorphism occur
When a nucleotide of the genetic code like T is not found where expected to but replaced by C
