Biology 2107                                                                     Fall,  2022

Test #2

 

 

Name: __________________________ Student ID:  __________________

 

 

Please circle the letters that precede the most appropriate answer to the question asked.  Be aware, there is only one answer to each question.  

 

Section 1 (22pts.)

 

1.         Given that, in barley plants, the allele for tall stalks is dominant over short stalks and the allele for wide

leaves is dominant over thin leaves. Assuming "independent assortment", what would be the best way to determine the genotypes of a given barley plant that exhibits tall stalks and wide leaves?

 

A   Undertake a "Test cross" between a Tall stalk and thin leafed barley plant against itself

B   Undertake a "Test cross" between a Tall stalk and Wide leafed barley plant with a short stalk and wide leafed barley plant

C   Self cross a Tall stalk and Wide leafed barley plant

D    Undertake a "Test cross" between a Tall stalk and Wide leafed barley plant against  a short stalk and thin leafed barley plant

E    Retake BIOL210

 

2.   How many “valence” electrons does carbon have in its outer shell?

 

A.            2

B.             3

C.             5

D.            4

E.             7

 

3.        In  Labrador retrievers, the allele for a black coloured coat (B) is dominant to the allele for brown fur coat colour (b). However, if a lab has two copies of the "recessive allele" for a "pigment-depositing gene" (e), it can only have yellow coloured fur. In a cross of two doubly heterozygous black labs (BbEe x BbEe), what fraction of the next generation would one expect to have yellow fur?

 

A.            3/8

B.             1/8

C.             1/16

D.            1/4

E.             5/8

 

4.   Given its ability to scrutinize allelic frequencies, the Hardy Weinberg equilibrium can determine..

 

A.             Precisely when a population will become extinct

B.             Precisely when a population became extinct

C.            The geographic movement of a population over time

D.            When a population went through a disaster, such as a “bottleneck”

E.             How long life has been around on earth

 

5.   At which phase in cell division do homologous chromosomes segregate

 

A.             Anaphase II of Meiosis

B.             Prophase I of Meiosis

C.            Metaphase II of Meiosis

D.            G phase 2 of Mitosis

E.             Anaphase I of Meiosis

F.             Metaphase of Mitosis

 

6.         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.

 

 

7.   If the atomic weight of sodium is 23, and the atomic weight of chlorine 35.5.  When 58.5 grams of sodium chloride are dissolved in a final volume of 2 liters of water, the solution is said to be:

 

A.             0.5 molar

B.             58.5 molar

C.            1 molar

D.            Cannot tell, because you cannot tell whether sodium chloride is formed between ionic or covalent bonds

E.             23 micromolar

F.             12.5 molar

 

8.   Which one of the following statements is true -according to the lecture notes.

 

A.       Bases accept H+; Acids donate H+

B.       If a compound increases the OH+ ion concentration when added to water, then the compound is said to be acidic

C.      All acids dissolve fully in water

D.     Acids accept H+; bases donate H+

E.     The pH value is defined as the positive logarithm of hydrogen concentration in moles    per liter (molar concentration).

 

9.   Hypertrichosis, hairiness of the pinna of the ear, is inherited as a Y-linked recessive in humans. If a man with hypertrichosis marries a “normal” woman and they have children, what is the most likely outcome?

 

A.             All offspring will have hypertrichosis

B.             Half the offspring will have hypertrichosis

C.            All the male offspring would be sterile

D.            Only half the female offspring would express hypertrichosis

E.             All offspring will have phenotypically normal ears

 

10.  RNA molecules are transported from the nucleus to the cytoplasm in eukaryotes through:

 

       A       The rough endoplasmic reticulum.

      B       The smooth endoplasmic reticulum.

      C       The Golgi apparatus.

      D       Nuclear pores

      E       Liposomes

 

11.   The term “Monoecious” refers to:

 

      G.      the number of chromosomes in a cell

      H.      the presence of both male and female structures exhibited by the same individual

                organism

      I.       the presence of only male or female structures exhibited by the same individual organism

      J.       the number of membranes present in a Gram positive bacterium

      K.      a genetic unit of hereditary

 

 

Section 1  (12 pts).
In the next several questions each question is worth 3 pts. 
Please circle your evaluation of the statement given.  If you believe the statement to be “False” then explain why you think so in the space provided.
 
Read each question carefully !

 

13.   With respect to proteins the term Tertiary structure” refers to the 3D organization of protein subunits in

            a complex protein, resulting in the final structure of a protein, like haemoglobin. 

 

True                                                               False

 

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14.   During Mitosis microtubular spindle fibres attach to the chromosomes through “kinetochores”.

 

True                                                               False

 

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15.       Macromolecules can be considered to be a molecule, whose molecular weight is greater than or equal to 1,000 Daltons 

 

True                                                               False

 

 

16.     The “Golgi apparatus” is an organelle in eukaryotes that modifies newly synthesized lipids for “export”  and passage around the cell

 

 True                                                               False

 

__BOTH ARE CORRECT _DEAD QUESTION________

 

 

Section 2 (50 pts)

 

Please answer the following questions in the space provided, using short, concise answers.

 

 

2.1 (3 pts.)

 

(a)  Give an example of a lipid.

 

   ______Glycerol, triglyceride. membrane lipid?  Oleic acid, steric acid____

 

2.1 (7 pts.)

 

            (b)  Define 2 major differences between each the following types of molecules:

 

Proteins and Lipids 

 

            alpha carbon, amino “acid”s  peptide bonds, vs. CHO, fatty acyl side chains, forming or not form

lipid bilayers, or micelles,  true vs false macromolecules, hormones? Waxy or oily

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   Similarities: Fundamentally Carbon, hydrogen and Oxygen , energy storage/source, polar or hrdrophobic side chains ___

 

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2.2.  (5 pts.) Briefly discuss the concept of “gene interactions”, giving at least one example

of such an occurrence.

 

   _____Epistasis, complementary genes________________________________________________________

 

   _____Labradors. Albino’s Purple Petal colour in pea plants._________________________ __

 

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2.3 (10 pts.)

 

Differentiate between an ionic bond and a hydrogen bond: giving an example

of each.

 

   Diagram

Description automatically generated

As opposed to sharing of electrons_____________________________________________________

Shape, polygon

Description automatically generated

 

 

2.4 (10 pts.) Given that I am already aware that water makes up ~70% of the human body

and that water covers ~70% the earth’s surface, from information that you have learned in

the lectures thus far, briefly discuss why water is considered to be so important to biologists

 

   Diagram

Description automatically generated   universal solvent, formation of Ice that is lighter than

 

   The liquid form, hydrogen bonds maintaining it as a liquid at room temperature, 

 

   Hydrolysis/ condensation building and breaking down macromolecules._______________________________

 

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2.5 (5 pts.) What is the difference between “Exergonic” and “Endergonic” reactions

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Exergonic : means "releasing energy in the form of work". In thermodynamics, work is defined as the energy

moving from the system (the internal region) to the surroundings (the external region) during a given process.

Negative Gibbs free energy.

 

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Endergonic:  chemical reaction in which the standard change in free energy is positive, and an additional driving

force is needed to perform this reaction. In layman's terms, the total amount of useful energy is negative

(it takes more energy to start the reaction than what is received out of it) so the total energy is a negative net result. 

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2.6. (5 pts.)

 

What’s the difference between “wild-type trait” and a “dominant trait”?  Please give an

example of a dominant trait that is NOT the “wild-type” trait.

 

____Wild  type allele is the allele that is present most in a population, and and be either dominant or recessive.

 

Dominant allele is the allele that will normally show through, even in the presence of its “recessive” allelle 

 

_Huntington’s disease._____________ ________________________________________________________

  

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2.7. (5 pts.) 

 

The frequency of two alleles in a gene pool is 0.20 (A) and 0.80(a).

 

If you assume that the population is in Hardy-Weinberg equilibrium

Calculate the percentage of homozygous recessives in this population.

______p2 +2pq+ p2 =1 _____________________________________________________________________

 

______0.8 x0,8 =   0.6  = 60%________________________________________________________________

  

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