bio test - genetics
Deduce the genotype of Queen Victoria’s daughter Alice.
XH Xh
State the stage of meiosis where chiasmata formation may occur.
prophase I;
Explain gene linkage and its effects on inheritance
located on the same chromosome;
genes/gene loci close together (on the same chromosome);
do not follow (the law of) independent assortment;
more chance of recombination if genes are further apart;
inherited together unless crossing over/recombination occurs;
ratios of offspring in dihybrid crosses are different from expected/non- Mendelian
more offspring with parental phenotype combinations than expected;
State processes occurring during interphase
DNA replication
cell growth
The mitotic index is an important prognostic tool for predicting the response of cancer cells to chemotherapy. Outline how the mitotic index is calculated.
number of cells (seen under the microscope) undergoing mitosis divided by the total number of cells (observed in sample area)
Identify the genotype of the male wire-haired dog.
WwKk
State the reason that O. sativa and O. rufipogon are classified as different species.
cannot interbreed to produce fertile offspring
Compare and contrast the trends for O. rufipogon and O. sativa indica
similarities :
both show diversity
OR
similar diversity between 2.4 to 2.7 mb
differences :
there are «two» major drops in diversity for O. sativa indica whereas none for O. rufipogon/much wider fluctuations in O. s. indica
O.s. indica much lower at PROG1
OR
O.rufipogon does not drop < 2.5 whereas O. s. indica approaches 0
State the proportion of the ancestral allele for the gene GS3 in the O. rufipogon-III population.
3/4 .. 0.75 .. 75%
Distinguish between the proportion of ancestral and derived alleles for all three genes in O. sativa indica and O. sativa japonica.
O.s. indica has more of the ancestral allele «for all three genes»
lower/higher values for ancestral/derived are not for the same genes
State one reason for having a control group.
any reference to comparison;
The purpose of the control group is to create a benchmark to compare the experimental results to
Using all of the data, discuss whether there is evidence that the two sub-species of O. sativa might have evolved independently from O. rufipogon
large difference in diversity index between O. s. indica and O. s. japonica «suggests independent evolution»
b. «some of the» peaks/troughs for O. s. indica and O. s. japonica in different positions «suggests independent evolution»
c. O.s. indica has a similar diversity index to O. rufipogon «which suggests closer relationship/recent divergence»
e. O.s. indica has similar large number of ancestral alleles to O. rufipogon I/II
List three characteristics of eukaryotic homologous chromosomes.
b. carry the same sequence of genes
d. both are present when nucleus is in diploid state
occur in pairs
centromeres are in the same position