Please circle the letters that precede the most appropriate answer(s) to the question asked. Be aware, there is only one answer to each question, if there are more than one plausible answers, choose the one that is most specific.
1. Assuming that the height of a pea plant is determined by a single gene at a single locus, when crossing a tall pea plant (Tt ) with a dwarf pea plant (tt) which of the following statements would be true
A All the F1 generation would be heterozygous tall
B All the F1 generation would be homozygous small
C Half of the F1 generation would be homozygous small
D Half of the F1 generation would be homozygous tall
E If all the F1 generation were to be “selfed” 1/4 of the offspring would be homozygous small
F If all the F1 generation were to be “selfed” all the offspring would be heterozygous tall
2. The term “Monoecious” refers to:
A The number of chromosomes in a cell
B The presence of both male and female structures exhibited by the same individual
C Bacteria with only one membrane
D A genetic unit of hereditary
E The genetic complexity of a Mendelian type cell
F A general term for a cell going through the first stage of Meiosis
3. Mendel’s 1st law states that:
A During gamete formation the segregation of one gene pair is independent of all other gene pairs
B Two members of a gene pair segregate from each other into the gametes, whereby one half of the gametes carries one of the traits, the other half carries the other
C The union of one gamete from each parent to form a resultant zygote is random with respect to that particular characteristic.
D Like all things biological, genes come in pairs.
E When fertilization occurs, the zygote gets one half of its chromosomal set from each parent, thus restoring the pair.
4. From the lectures, what is meant by the term “test cross”
A The cross fertilization of an ovum with a single spermatozoa
B A cross that checks whether or not individuals from two different species are compatible.
C A cross that checks whether or not individuals from the same species are compatible.
D A cross between a true breeding strain for a particular trait under scrutiny and a wild-type version for the given trait.
E A cross between an individual and another individual that is a homozygous recessive for the particular trait under scrutiny
5. Which one of the following examples from the lecture series would best fit into the category of “multiple alleles”.
A Hair colour in horses
B M and N blood groups
C Shape of the “purse” in Shepherd’s purse
D ABO blood groups
E Height in humans
F Petal colour in carnations
6. A mother of four (3 girls and 1 boy) exhibits a recessive X-linked trait. Assuming that she married a man who did not, what is the most likely outcome in their offspring (according to the laws of probability).
A All the offspring exhibit the trait.
B Both boys would appear to be wild-type.
C None of the girls would exhibit the trait
D None of the offspring would exhibit the trait.
E One of the girls would be a carrier, while the other two would exhibit the trait.
F The boy has a 50% probability of exhibiting the trait.
7. A trait is said to be “pleiotropic” when.
A It defines a phenotype that is highly variable
B it has more than three loci
C it is found in two different species
D it gives rise to more than one phenotype
E it masks the expression of other genes
8. If you crossed a true-breeding yellow-seed plant (AA) with a heterozygous yellow-seed plant (Aa), offspring:
A The genotypes would be 1 AA : 2 Aa.
B genotypes would be 1 Aa : 1 aa.
C genotypes would be 1 AA : 1 Aa.
D phenotypes would be 1/2 yellow-seed plants and 1/2 green-seed plants.
E genotypes would be 1 Aa : 1 aa and would be 1/2 yellow-seed plants and 1/2 green-seed plants
9. (6 pts.) Take a look at the following figures and, using the information given as well as your knowledge of the course thus far, give the most straight forward answer to the three questions by circling the most appropriate answer. (2pts for each part of the answers in this question).
(a) The cell is in:
A Prophase II
D Metaphase II
E Anaphase I.
F Telophase I.
(b) This cell is:
A A “germ-line” cell
B A “recombinant” cell
C A “somatic” cell
D A “cancerous” cell
E There is insufficient information to choose.
(c) This cell is in:
A Prophase I
B Anaphase II
D Metaphase II
E Anaphase I.
F Telophase I.
10. “Hemizygous” refers to the number of chromosomes in a gamete.
__Hemizygous is a condition where only one copy of a gene or DNA sequence is present in diploid cells__
11. If present the genotype of a dominant allele will always show through in the phenotype.
__What about Epistasis??? __
12. “Multiple genes” rarely, if ever, give rise to a Mendelian-like distribution of their phenotype
13. Nondisjunction results when homologous chromosomes fail to separate during
prophase I of Meiosis.
__Chromosomes don’t separate in “prophase I” __
14. Almost by definition, all of the traits that Mendel analyzed in his dihybrid crosses were derived from genes that were located on different chromosomes.
__Some were on the same chromosome__
15. Sex-linked traits always refer to genes located on the X-chromosome.
__What about the Y chromosome??? __
Bonus pts: Give an example of an X-linked trait in humans _Haemophilia, Red / Green Colour blindness__