Genetics Review Flashcards
What is heredity?
The delivery of characteristics from parent to offspring
What is the different between sexual and asexual reproduction?
Sexual does not produce identical offspring while asexual reproduction does.
How are the family generations labeled in a genetic cross?
Filials
What is Mendel’s Principle of Dominance?
Different alleles are dominant and recessive
What are alleles?
Forms of genes
What is the Principle of Segregation?
Separation of alleles during the formation of sex cells (gametes)
What is true breeding? (pure)
An organism that always produces offspring identical to itself if self pollinated
What is the Principle of Independent Assortment?
Genes for different traits can segregate independently during the formation of gametes, the chromosomes assort not the individual genes
What is incomplete dominance?
- Neither allele is considered recessive
- A hybrid will produce a blend of the two traits
What is Co-dominance?
- Neither allele is considered recessive
- A hybrid displays both traits from each allele
What is a multiple allele?
- There can be more than 2 alleles
- This can lead to multiple phenotypes
What is a polygenic trait?
- Some traits are controlled by more than one gene
- Large number of phenotypes
What is the difference between a diploid and haploid cell?
A diploid (2N) cell has the full # of chromosomes and a haploid (N) cell has 1/2 the # of chromosomes
What is meiosis?
The process of a diploid cell dividing to produce 4 haploid cells
What is prophase 1?
Chromosomes pair with its corresponding homologous chromosomes forming a tetrad (synapsis)
What is metaphase 1?
Spindles attach to chromosomes moving tetrads to the equator
What is anaphase 1?
Spindles pull homologous chromosomes towards opposite poles
What is telophase 1?
- Nuclear envelope reforms
- Cell separates into 2 haploid cells
What is prophase 2?
Each daughter cell has half the # of chromosomes as the original cell
What is metaphase 2?
Whole chromosomes move to the equator
What is anaphase 2?
Sister chromatids separate and move to opposite poles
What is telophase 2?
- Nuclear envelope reforms
- 2 haploid cells have changed into 4 haploid cells
When is there a diploid cell and when is there a haploid cell?
Diploid cell until telophase 1
What is synapsis?
Forming of a tetrad
What is a tetrad?
A pair of homologous chromosomes
What is crossing over?
The exchange of alleles between homologous chromosomes and produces new combinations of alleles
When does crossing over take place?
Prophase 1
What is a somatic cell?
All cells other than sperm or egg cells
What is a gene map?
Shows the relative locations of each genes on a chromosome
What is a chiasma?
The crossover points in chromosomes
What is Morgan’s Principle of Gene Linkage?
Each chromosome is actually a group of linked genes
