exam 2 Flashcards
(38 cards)
What are characteristics of a good model organism?
short generation time, many offspring, easy to maintain, small, easy to arrange matings, easily recognizable traits, inexpensive to care for
Monohybrid Cross
mating between individuals that are heterozygous for a single trait (AaxAa)
Dihybrid Cross
mating between two individuals that are heterozygous for two traits (PpxSs) → PS,Ps,pS,ps
chromosome theory of inheritance
chromosomes are composed of Mendel’s hereditary determinants, or what we know now as genes
Mendel’s Principle of Segregation
genes must segregate equally into gametes such that offspring have an equal likelihood of inheriting either factor
Mendel’s Law of Dominance
in a heterozygote one trait will conceal the presence of another trait for the same characteristic
Mendel’s Principle of Independent Assortment
genes do not influence each other with regard to the sorting of alleles into gametes and every possible combination of alleles for every gene is equally likely to occurs
What is a autosomal trait?
a way a genetic trait or condition can be passed down from parent to child. one copy of a mutated gene from one isn’t can cause the genetic condition, a child who has a parents with the mutated gene has 50% chances is inheriting that mutated gene
how to tell if a trait is autosomal or sex-linked?
if a trait appears equally often in males & females, it is likely to be autosomal. if males are more likely to have the trait, it is usually x-linked.
What is a sex-linked trait?
when a gene being examined is present on the X, but not the Y chromosome it is X-linked
incomplete dominance
one of the alleles appears in the phenotype in the heterozygote but not to the exclusion of the other one which can also be seen
codominance
both alleles for the same characteristic are simultaneously expressed in the heterozygote think of A or B blood type
epistasis
an interacting between genes such that one gene makes it interferes with the expression of another
polygenic traits
a characteristic, such as height or skin color, that is influenced by two or more genes. since multiple genes are involved polygenic trait do not follow Mendelian inheritance
how can genes be affected
genes can be affected by the physical environment as well as the genetic environment
what are the two category of cells in the nervous system
neurons and gila
DNA Replication
each of the two strands that make up the double helix serve as a template from which the new strands are copied, the new strand will be complementary to the parental strand
Gel Electrophoresis
a technique used to separate charged molecules based on size and charge, nucleic acids can be separated as whole chromosome or as fragments. loaded into a slot at one end of the gel matrix and an electric current is applied to the gel, which causes the negatively charged molecules to be pulled toward the end with the positively charged electrode.
Polymerase Chain Reaction (PCR)
used to rapidly increase the number of copies of specific regions of DNA for further analyses
what does a PCR contain?
sample of double-stranded DNA, two artificially synthesized primers, four dNTPs, DNA polymerase that can tolerate high temperatures, salts, and pH buffer
PCR Amplification
denature: DNA strands are denatured through heating; anneal: the reaction is cooled to allow primers to anneal to template strands; extend: the reaction is warmed so DNA polymerase catalyzes new strands
What are some uses of PCR?
paternity analysis, identification of the owner of a DNA sample left at a crime scene, comparison of small amounts of ancient DNA with modern organisms, determining the sequence of nucleotides in a specific region
neurons
excitable, can generate and transmit electrical signals called action potentials
gila or gilal cells
provide support and maintain the extracellular environment
