1- During which of the following processes is ATP produced?
ATP is produced during both the anaerobic and aerobic phases of cellular respiration as well as during the light-dependent reactions of photosynthesis.
In photosynthesis, ATP is produced by photophosphorylation. During cell respiration, ATP is produced by oxidative phosphorylation.
2- The cells of the yellow dung fly contain 5 pairs of autosomal chromosomes and one pair of sex chromosomes. Upon completion of Meiosis II, how many chromosomes will each yellow dung fly gamete have?
The cells of the yellow dung fly have 12 chromosomes:
5 pairs of autosomal chromosomes= 10 autosomal chromosomes
one pair of sex chromosomes= 2 sex chromosomes
Meiosis is a cell division that leads to the formation of gametes that contain half the chromosomal material. Hence, at the end of meiosis II, the number of chromosomes in yellow dung fly gamete is 6.
3- A scientist performed an experiment to determine the effect of temperature on the length of the cell cycle in one of the species. The duration of the cell cycle at room temperature is 15 hours. He cultured identical stem cells in four culture media with the same content of nutrient and oxygen gas but at different temperatures. The duration of the cell cycles at different temperatures are recorded in the following table:
| Temperature (oC) | Length of the cell cycle (hours) |
| 10 | 54.6 |
| 15 | 29.8 |
| 20 | 18.8 |
| 25 | 13.3 |
At room temperature, the duration of the cell cycle is 15 hours. Comparing the obtained results, we can notice that with a temperature of 10oC the length of the cell cycle increases to become 54.6 hours instead of 15 hours. When we increase the temperature to 20oC, the length of the cell cycle decreases to become 18.8 hours approximately equal to the length of the cell cycle in room temperature (15 hours). A same result, when the temperature is 25oC, the length of the cell cycle is 13.3 hours. Hence, the cell divides faster when the temperature increases.
4- Eutrophication refers to:
Runoff form sewage and manure from pastures increase nutrients in lakes. Great concentrations of algae and microscopic organisms, often develop on the surface, preventing the light penetration and oxygen absorption necessary for underwater life. Shallow areas become choked with weeds, and swimming and boating become impossible. As these large populations of photosynthetic organisms die, two things happen. First, organic material accumulates on the lake bottom and reduces the depth of the lake. Second, detritivores use up oxygen as they decompose the dead organic matter.
5- In spring and winter, the food of the fox is mostly small rodents due to the lack of fruits. By contrast, in summer and autumn, its food consists of 50% fruit. So the diet of a fox, as function of seasons, is:
The fox is eating food that comes from plants (fruits) and from animals (rodents). Hence, the diet of the fox is omnivorous.
6- A farmer retired and moved away. He left his land to grow wild. What will he find when he comes back after a while?
Since the environment will change, both the plants and animals will change. The plants will change in response to the changes in the environment, and the animal will change in response to the changes in plants.
7- In the inheritance of blood group ABO system, the alleles behave as follows:
The ABO system is determined by a gene having three alleles: allele A, allele B that are codominant and allele O that is recessive. The following table represents the genotype and the corresponding phenotype:
| Phenotype | Genotype |
| A | A//O or A//A |
| B | B//O or B//B |
| O | O//O |
| AB | A//B |
8- Which of the following statements best explains the fact that a mutation in a cell’s DNA does not always result in an error in the polypeptide produced from that DNA sequence?
Silent mutation that occurs to DNA doesn’t affect the polypeptide produced because of the redundancy of the amino acids: Redundancy in the genetic code means that most amino acids are specified by more than one mRNA codon. For example, the amino acid phenylalanine (Phe) is specified by the codons UUU and UUC. Hence, if this mutation in the DNA leads to the codon that code also for the amino acid that existed before, the polypeptide will not be affected.
9- Tay-Sachs disease is known as an infantile disease which is characterized by relentless deterioration of mental and physical abilities. It begins at 6 months of age and usually results in death by the age of five. A couple has two girls out of which one is 2 years old and has the disease. The mother got pregnant and she is afraid of having another affected child. She visited a genetic counselor who demanded DNA analysis test for the whole family. The results of the DNA analysis of the whole members are shown in the following table.
| Bands | Mother | Father | Normal Girl | Affected Girl | Fetus |
| A | |||||
| B | |||||
| C |
Based on the DNA analysis, we can find that the mother and the father present 3 bands A, B and C. Comparing these bands to those present in affected girl, we can detect that band C correspond to the disease and in addition, this disease is a recessive disease. Hence, bands A and B correspond to normal allele, normal phenotype.
10- The figure below shows the anatomy of an earthworm. The structure responsible for grinding food is represented by the letter:
The following scheme corresponds to the digestive system of the earthworm. The corresponding organs are:
A- Mouth
B- Esophagus
C- Crop
D- Gizzard
E- Intestine
After their ingestion, the food will be grind in the gizzard than passes to the intestine.
11- The following figure shows the training of a dog in order to sit. This training refers to
Operant conditioning is trial and error conditioning. This is how we train animals. In this case, a system of rewards is the way the dog is trained: if he sits, he will get to eat.
12- A gynecologist prescribes a treatment to a newly pregnant woman who suffered from a miscarriage a year ago. This treatment is composed of one main hormone that maintains a supportive environment for the developing fetus. Which hormone is this medication composed of?
Progesterone helps the fertilized egg be implanted in the uterus to establish a pregnancy and help maintain a healthy pregnancy. Women naturally produce progesterone in the ovaries, the placenta, and the adrenal glands during pregnancy. In this case, due to a miscarriage a year ago, this woman should be supplemented by progesterone in order to maintain a good uterus to the implantation of the embryo.
13- Which of the following is LEAST likely to result in speciation?
A species is a population whose members have the potential to interbreed in nature and produce viable, fertile offspring. Anything that fragments a population and isolates small groups of individuals may foster the formation of new species.
14- Wildebeests separated from each other by a newly formed river are now separate species. This fact corresponds to:
Divergent evolution occurs when a population becomes isolated (for any reason) from the rest of the species and becomes exposed to new selective pressures, causing it to evolve into a new species. In this case, we can find that the newly formed river induce the separation of wildebeests. Hence, this case corresponds to divergent evolution.
15- In a certain population of goats, there are two alleles for coat color: brown and white. Brown is dominant and white is recessive. The frequency of white-colored goats is 20% during spring season. Wolves are also present in the area, and goats constitute a major portion of their diet. Wolves recognize prey when they do not blend into the environment. If the climate were to change so that snow covered the ground much of the time, what change in the population of goats would you expect?
If the climate changes and the ground is covered by snow more of the time, then goats that are better camouflaged will survive while animals that are not camouflaged will be killed and eaten by wolves. So animals with white fur will survive better than animals with brown fur, and the frequency of the allele for white fur will increase in this population.