Welcome to your Biology national exam 2012
1.
Which of the following viruses is a RNA virus?
2.
Which one of the following statements is true regarding the need for recycling nutrients through an ecosystem?
3.
answer this question based on following steps of nitrogen cycle.
are represented by the letters W,X,Y and Z are, respectively.
4.
What is the impact of humans on the Sulphur cycle? Production of:
5.
As succession progresses, the bare land turns out to be productive due to the fact that the
6.
Consider the following digram of HIV virus
What does 'number 1’ represent?
7.
What is the economic impact of AIDS?
8.
A geographical area with specific climate, soil type, plants and animals with similar adaptation is.
9.
As energy from the sun, enters the ecosystem in the form of light, one of the following happens to it. It
10.
Support a self fertilizing organism has AaBb genotype, how many different types of gametes would it produce if there is no linkage?
11.
What is the chemical composition of bacterial cell wall?
12.
In this biology section, a biology student applied a Gram stain two groups of bacteria named X and Y.
At the end, he observed that the bacteria X stained purple while bacteria Y stained pink, which of the following could be the correct conclusion of his experiment? Bacteria.
13.
As compared to infections diseases, functional diseases:
14.
Which of the following products does NOT need the role of bacteria?
15.
Bacteria are used in the production of vinegar to:
16.
Among the parts of the cell, which organelles are bounded with double membrane?
17.
Why are cells that secrete hormones and enzymes rich in rough endoplasmic reticulum? Because they produce more:
18.
What is the role of cholesterol in the cell membrane? To
19.
If potato cells are immersed in a hypertonic solution, they will
20.
Which molecule of the plasma membrane contains carbohydrate chains and allows identification of the cell by the immune system?
21.
Red green color blindness is due to X-linked gene and determined by the recessive alleles. Which one of the following is true about this condition?
22.
Which one of the following statements is true about chromosome? It is
23.
What is the complementary strand for a DNA strand the following sequence of bases?
24.
Consider the following disordered events of transcription.
I RNA polymerase crosses a stop sequence in
the gene.
II RNA polymerase reads the antisense DNA
strand and builds mRNA.
III mRNA molecule detaches from DNA and
the DNA rejoin.
IV. RNA polymerase binds to the promoter which signals the DNA to unwind.
Which one is the correct sequence of events during transcription?
25.
Which of the following bases are the triplets of codes in the mRNA that cease translation and the ribosome folds the polypeptide into its final structure?
26.
By which level of precipitation, temperature and type of plants is the Taiga biome characterized, respectively
27.
In which biome are epiphytes common?
28.
What makes Ethiopia rich in biodiversity which deserves a global attention?
29.
Why maintaining habitats is the key and fundamental aspect to conserve biodiversity? Because
30.
Among the following statements, which one is correct about mutations?
Mutations
are changes in genetic composition of
population
31.
If the particular triplet of bases in the sense strand of DNA is AGT, then the corresponding codon for the transcribed mRNA will be
32.
The table below compares the two types of competition.
In the above table, which rows contain WRONGLY stated statements with respect to the types of competition?
33.
What is the theory that states disease is caused by micro organisms?
34.
In the bare bottom of a newly formed pond a biologist observed emergence of new algae. The form of succession he observed can be best described as
35.
The extent to which variability exists among living organisms, with in species and even between ecosystems is known as
36.
The chromosomal mutation that results Down's syndrome is
37.
When a piece of one chromosome is transferred to another non-homologous chromosome, such kind of mutation is called
38.
Consider the following diagram of the shapes of bacteria Which of the following shapes of bacteria belongs to spirochetes?
39.
Which of the following diseases have water as their reservoir?
40.
The following table compares viruses with free-living cells.
Which rows of the above table contain the
correct comparison?
41.
The rucleotides that build up the DNA molecule contain the following base EXCEPT
42.
Which one of the following is the significance of biodiversity?
43.
The carrying capacity of a population can be defined as the
44.
Id pea plants with round yellow heterozygous seeds are self-fertilized and produced 4800 seeds, hoe money round green seeds will be produced (Hint: round yellow seed is dominant).
45.
A grade 12 student extracted an insulin gene from insulin producing cells of the pancreases and plasmid from bacteria
46.
What will happen to the population size if the Rate fatally is less than the rate of mortality?
47.
Which one of the following statements is correct about the stages of population growth rate curve?
48.
Consider the following pedigree of albinism What will be the possible genotypes of the parents?
49.
In which phase of meiosis does pairing of chromosomes and exchange of segments take place?
50.
During meiosis does is important to increase variation of gametes with regard to alleles that are
51.
Which organic molecules in our body have functions as antigens and antibodies of the immune system?
52.
If -glucose reacts with fructose molecule in a condensation reaction, what will be the chemical formula of the disaccharide formed in this reaction?
53.
In a structure of amylose molecule that contains one hundred a- glucose monomers, how many a-1, 4-glycosidic bonds are formed?
54.
In grade 11 laboratory class, the teacher gave the students a sample of food and asked them to investigate the presence of glucose. What kind of test with result will enable the students to confirm the presence of glucose?
55.
A group of grade 12 students carried out four biochemical tests to investigate the composition of four different food samples. The resells with the respective types of tests are shown in the table below.
Which food samples contained both lipid and Protien
56.
Identify the correct statement about enzymes. They
57.
Which one of the following options contains only a group of organic biochemical molecules?
58.
Unbalanced hydrogen bonding at the surface of the water is responsible for high
59.
Identify the organic molecule which is correctly paired with its function .
60.
Which one of the following options contains the main steps of scientific method in their correct order?
61.
Which part of phospholipids in considered as hydrophobic region?
62.
A change in temperature can affect the rate of enzyme controlled reaction by
63.
Francesco Red disproves the belief that rotting meat produces flies.
He used wide mouth jars containing meat. He left some jars open to
the air and others were covered with a piece of gauze. What do you
think might have been Redi's most plausible hypothesis?
64.
Suppose a grade 12 student wants to investigate the need of CO for photosynthesis. He distracted plant A and B then he placed plant A in a bell jar which has no CO, in the surrounding air, while plant B in a bell jar which has normal level of CO. He placed the jars in a place light for 12 hours and kept other variables constant. Finally, he tested for the presence of starch. Less starch was produced by plant A than plant
65.
Helen was conducting iodine test for starch. She took two different food samples and placed one of the samples in test tube A and the other in test tube B. She added a few drops of iodine solution to both test tubes. Finally, she observed blue-black color in test tube B, but the sample in test tube A remained unchanged
66.
A field biologist can measure the slope of an area by using
67.
If the amount of enzyme is kept constant and the substrate concentration is gradually increased, hat will happen to the rat of reaction? The reaction velocity
68.
The following reaction shows enzyme controlled metabolic pathway in a living cell.
Substance W E 1 Substance E2
Substance Y E3 Substance Z
What will happen if the concentration of substance Z increases beyond the cell's requirement?
69.
How is the process of end- product inhibition triggered? By
70.
Identify the WRONG statement about the modern cell theory.
71.
During the practice of genetic engineering, bacteria are important to
72.
Consider the following diagram of a bacteriophage.
In the above diagram, the viral capsid is represented by number
73.
Which one of the following steps of HIV life cycle comes first?
74.
Which one of the following anti-retroviral drugs prevents the assembly of new virus particles?
75.
Which one of the following statements is correct about the reproductive cycles of lytic and lysogenic viruses?
76.
An enzyme which is designated as EC 2.7.1.2 can be grouped to which class of enzyme?
77.
Using enzyme technology in industrial production helps to reduce global warming. This is because enzymes?
78.
How do enzymes lower the activation energy of substrate molecules according to the induced-fit model? By
79.
If an enzyme depends on a cofactor for its activity, then the enzyme becomes active and functional when it is found in the form of
80.
Which one of the following enzymes requires copper ions for its catalytic activity?
81.
Which stage of cellular respiration is correctly paired with its site?
82.
What happens during the process of electron transport chain? Protons
83.
Identify the correct statement about the role of NAD and fAD during aerobic respiration. They
84.
Which of the following products are formed in anaerobic respiration of one glucose molecule in animal cells?
85.
Which one of the following options represents the correct catabolic pathway of the given respiratory substances?
86.
One benefit of water related to its high specific beat capacity is its importance
87.
A medical laboratory technologist at Black Lion Hospital placed a solution of stool in a centrifuge to separate the particles quickly for school test. Which one of the following will happen when he spins the centrifuge at high speed?
88.
The relevance and promise of Biology as a field of science can be best explained by its application in
89.
Biologist played a role in the against AIDS because they developed
90.
Which one of the following statements shows willingness of participating in a community undertaking against HIV and AIDS? A person who
91.
Where does the production of ATP and reduced NADP take place?
92.
Suppose 60 divisions on the scale of an eyepiece graticule come spend to 20 small divisions on the stage micrometer. Each small division on the stage micrometer is 15 m. If 6 cells for across 62 divisions on the stage graticule, what is will be the length each cell?
93.
Which one of the following is NOT the function of cells
94.
Consider the following table which compares prokaryotic and eukaryotic
when comparing the two types of cells in the above table, the numbers I, II, III and IV represents, respectively
95.
Cellular activities are carried out more efficiently in eukaryotic cells than prokaryples and this can be explained by the
96.
In the structural arrangement of cell membrane, the organic molecules which serve as the structural backbone and prevent uncontrolled movement of water soluble materials are
97.
The biochemical mechanism by which chlorophyll absorbs light energy is efficient because:
98.
The leaves of C3 plants in the tropics close their stomata to minimize water loss, as a result concentration of CO2 in the leaves falls.
When the C3 plants face such problem, ribulose bisphosphate reacts with oxygen and produce.
99.
Sorghum and wheat are C4 plants which are well adapted to photo synthesize efficiently in hot and bright days. Peas and carrots would not photosynthesize efficiently in such conditions because they are C3 plants. In which of the following features in the bundle are similar? The
100.
Plants that follow CAM photosynthetic pathway carry out the two stages of photosynthesis at different times. Which of the following products are formed during the night?
