Lab 09 Flashcards
What is the hypothesis
The body colour/wing type is mendelian so the observed value will be a 9:3:3:1 ratio
What is the animal we are looking at
Drosophilia melongaster
What is a dihybrid cross
A cross between organisms that are each heterozygous for both characters being observed
What is sexual reproduction
The fusion of two sex cells such as sperm and egg cell and therefore results in doubling of chromosome numbers.
What is meiosis
Meiosis is the reduction in chromosome number of cells to assure that the chromosome numbers in the cell stays the same from generation to generation. The number turns from diploid (2n) to haploid (n), in 2 successive divisions.
What is a sex cell called
It is called a gamete and has a haploid number of chromosomes
What is a gene
A discrete unit of heredity info consisting of a specific sequence of nucleotides in DNA, the two genes in a pair of homologous chromosomes need not to be identical at the DNA level
What is genetics
The science of heredity and variation
What is heredity
The transmition of traits from one gen to the next
How is variation demonstrated
Difference in apperance between siblings
What type of gene divisions are there
Some genes divide following the law of independent assortment, some genes are linked because they are close on the chromosome
What is the law of segregation
Two alleles of a heritable character segregate during gamete formation thus an egg and a sperm only gets one of two alleles
What is the law of independent assortment
each pair of alleles segregates independently of each other
What is a punnett square
A diagram for predicting the results of a genetic cross between individuals of known genetic makeup
What is a chi square test
Tells us whether or not we have any reason to doubt the null
