Ecology 107 Midterm: I hereby pledge that my answers on this exam are entirely my own, & I only used materials provided by Dr. Kilpatrick in the course. I understand that doing otherwise constitutes cheating. Name:_______________________ See equations on page 5 . 1) The graphs below show the classic research I showed in class by Gause from 1934 were he examined competition between two species of Paramecium .

He started each species off with 5 individuals of in flasks of media alone. He next measured the nutrient use of both species. He found that P. aurelia used 2/3 of the resource that limits P. caudatum populations (nitrogen), whereas P. caudatum used 1.0 times as much of the resource that limit P. aurelia populations (phosphorus) (the different resources limiting Pa and Pc makes competition asymmetric). a) Use this information to construct a “state-space†graph (below). Draw isoclines for the two species using different colors and label them by putting a box around the name with the color for that species (6 pts). Remember that an isocline is a line where the population growth rate, dN/dt, for that species is 0.

The endpoints of the isocline for a hypothetical species 1 (competing with species 2) are K1 and K1/21. The competition coefficient 21 measures the impact (or conversion) of species 2 on (or into) species 1 in terms of the resources that limit species 1 (& vice versa for 12). What are the values of these parameters: (4 pts) Kpa= pcpa= Kpc= papc= b) If we start with 50 Pa and 100 Pc, what will happen? Trace the path of the two populations through the state-space graph: Put a point at 50 Pa and 100 Pc, and move in the appropriate direction based on the isoclines. If you encounter an isocline or one of the axes, re-assess the correct direction.

If you reach the intersection of both lines stop (both species co-exist at equilibrium). If you reach an intersection of an axis and an isocline and the correct direction is to go off the graph into negative space, stop (one species has gone extinct while the other is at equilibrium). Kpc Kpa Kpc/ Kpc/ c) Put a second point at 250 Pa, 100 Pc and repeat the same process as in (b) until you stop again. (4 pts) d) (4 pts) Interpret these results biologically. Can these two species co-exist together or does one go extinct? Does it depend on the starting population sizes? e) At equilibrium, what are the abundances of the two species and which species is more abundant? (2 pts) f) You wanted to grow the two paramecium species as fast as possible to send paramecium to biology classes all across the world.

At what density should you grow them, and how long would this take , starting at a density of 5 (see top figs)? Density Pa (1pt): Day Pa (1pt): Density Pc (1pt): Day Pc (1pt): g) What is the fastest rate you could sustainably harvest each species? Show your work! Maximum harvest Pa (2pts): Maximum harvest Pc (2pts): h) What is the maximum per capita population growth rate, r, for each species? Show your work!

Pop growth rate r Pa (2pts): Pop growth rate r Pc (2pts): 2) An ornithologist studies two populations of birds called song sparrows. One population is migratory and spends winters in Santa Cruz and summers in Alaska. Migration, and variability in the arctic environment make it so that over a long time (decades), a quarter of the time the discrete-time annual population growth rate is 4.0 (good conditions), a quarter of the time is 1.0 (medium), and half the time is 0.5 (bad) (all are based on just females). Amazingly, the other population doesn’t migrate at all, but just lives in British Columbia (B.C.) all year long. There the conditions are more stable and the population growth rate in all years is 1.1. a.

If there were 50 female individuals in each population this year, and conditions in Alaska were those given in the table over the next 5 years, what would the population sizes be (fill in the table)? (5pts) Year B.C. population at beginning of this year Alaska population at beginning of year t Alaska Conditions in year t Now ( Good 1 Bad 2 Bad 3 Medium 4 b. What is the long-term trajectory of these two populations (growing, shrinking, stable) and why (what is the average % growth or decline each year over the long term)? Alaska/Santa Cruz (1pt): British Columbia (2 pts): 3) For this question, use the page with color maps of temperature and precipitation and biomes. a. What is the annual avg temperature, annual precipitation and likely biome at the place indicated by the tip of the arrow in South America?

Temperature (1pt): Precipitation (1pt): Likely Biome (1pt): b. Why is it so cool at this location compared to Paraguay (the small country to the southeast of the arrow that is all in red on the Temperature map) (1pt)? c. Why is it likely so dry at this location compared to areas to the east? Explain. (2 pts) d. If climate change warms this region by 3C, will this change the biome in this location?

Why? (2 pt) 4) a. Use the data in the table to make a plot of the rate of photosynthesis of a plant species versus temperature. Label the axes, plot the points and connect them with a line/curve. (3pts) Temp (C) Rate of Photosynthesis (μmol O2/m2s) b. What range of temperatures does a plant in South America experience, if mean annual temperature at its location is 10C, and there is a 10C difference between the warmest month (January) and coldest month (August), and a 20C difference between the hottest hour of the day (3pm or 15:00 in military time) and coldest hour of the night (5am or 5:00)? On the figure to the left, draw two curves (with different colors), one for the temperature (y-axis) vs time for one day during January and one for one day during August (and label them!).

You may want to figure out what the maximum temperatures are in the hottest month at the hottest hour, and the same for the coldest hour on the coldest day before drawing the temperatures vs time. Put numbers on the y-axis. (4 pts) c. Will 3C of warming increase or decrease photosynthesis by the plant at the location from part 4b? Will the effect be the same across all months and times of the day? Explain. (3 pts) d.

If a plant of this species weighed 150g (including its roots!), calculate the approximate metabolic rate of this plant at the mean annual temperature before and after climate change. Metabolic rate before climate change (2pts): Metabolic rate with +3C warming (2pts): What is the ratio of the metabolic rates (MR), MRafter/MRbefore (1pt): e. Using the figure above, what is the rate of photosynthesis at the mean annual temperature before (10C) and after climate change. Photosynthetic rate before climate change (1 pt): Photosynthetic rate with +3C warming (1 pt): What is the ratio of the photosynthetic rates (PR), PRafter/PRbefore (1 pt): f. For most plants the rate of photosynthesis is about twice the rate of respiration (the metabolic rate).

Will warming be a net benefit or a net cost to the plant, and is the net cost/benefit the same at all times of year and all hours of the day? Explain. (3 pts) g. If the plant grows additional leaves so that it doubles its surface area from 0.10m2 to 0.2m2 and doubles its mass from 150g to 300g, will this make the plant more or less efficient, and by how much? Efficiency is photosynthetic rate for the whole plant/metabolic rate for the whole plant. Remember that the rate of photosynthesis is given in units of O2/m2s, which means that an increase in leaf area (m2) linearly increases the whole plant rate of photosynthesis.

At the average annual temperature, what is the ratio of the metabolic rate of the bigger plant to the smaller plant, and what is the ratio of the photosynthetic rates of the bigger and smaller plant? Ratio of metabolic rates, big/small (2pts): Ratio of photosynthetic rates, big/small (2pts): Is the bigger or smaller plant more efficient and why? (3 pts) h. If the temperature on the leaf surface in the sun reached 30C and the plant wanted to reduce its temperature to more efficiently photosynthesize, what are two ways it could “thermoregulate†(cool down) and what are tradeoffs that might occur if the plant used these strategies? Equations and other information Nt=N0ert; Nt=tN0 if >1, then -1 = % increase per year; if <1, then 1- = % decrease per year. ; K = carrying capacity, r = per capita pop growth rate, MSY = rK/ measures the impact of species 2 on population growth rate of species 1 in terms of the resources that limit species 1, and vice versa for 12.

Adiabatic cooling : -7C for each 1000m of elevation Metabolic rate (in W) = c*M3/4e[-E/(kT)]; where c=e20, M is mass in grams, E is activation energy, 0.63eV, k is Boltzmann’s constant, 8.617x10-5 eV/K; and T is Temperature in K (0C = 273.15K) For Question 3: The maps below show annual precipitation (top), annual average temperature (middle) and likely biomes given temperature and precipitation (bottom). 2 ෠ภචৠè ঠ- = ෠ภචৠè ঠ- = K N K rN K N rN dt dN 1 ෠෠ภචৠৠè ঠ- - = ෠෠ภචৠৠè ঠ+ - = ෠෠ภචৠৠè ঠ- - = ෠෠ภචৠৠè ঠ+ - = ® ® ® ® K N N K N r K N N N r dt dN K N N K N r K N N N r dt dN b b a a 1.cm/yr DensityTime (days)P. aurelia DensityTime (days)P. caudatum P. aurelia P. caudatum Read register 1 Read register 2 Write register Write data Registers ALU Zero Read data 1 Read data 2 Sign extend 16 32 Instruction [31–26] Instruction [25–21] Instruction [20–16] Instruction [15–0] ALU result M u x M u x Shift left 2 Shift left 2 Instruction register PC 0 1 M u x 0 1 M u x 0 1 M u x 0 1 A B M u x ALUOut Instruction [15–0] Memory data register Address Write data Memory MemData 4 Instruction [15–11] PCWriteCond PCWrite IorD MemRead MemWrite MemtoReg IRWrite PCSource ALUOp ALUSrcB ALUSrcA RegWrite RegDst 26 28 Outputs Control Op [5–0] ALU control PC [31–28] Instruction [25-0] Instruction [5–0] Jump address [31–0] Control Hazard detection unit + 4 PC Instruction memory Sign- extend Registers = + Fowarding unit ALU ID/EX MEM/WB EX/MEM WB M EX Shift left 2 IF.Flush IF/ID M u x M u x Data memory WB WBM 0 M u x M u x M u x M u x WB M EX WB M WB M em W rit e PCSrc M em to R eg MemRead Add Address Instruction memory Read register 1 Read register 2 Instruction [15–0] Instruction [20–16] Instruction [15–11] Write register Write data Read data 1 Read data 2 Registers Address Write data Read data Data memory Add Add result ALU ALU result Zero Shift left 2 Sign- extend PC 4 ID/EX IF/ID EX/MEM MEM/WB 16 632 ALU control RegDst ALUOp ALUSrc R eg W rit e In st ru ct io n Branch Control 0 M u x 1 0 M u x M u x M u x MemRead ALUSrcA = 0 IorD = 0 IRWrite ALUSrcB = 01 ALUOp = 00 PCWrite PCSource = 00 ALUSrcA = 0 ALUSrcB = 11 ALUOp = 00 ALUSrcA = 1 ALUSrcB = 00 ALUOp = 10 ALUSrcA = 1 ALUSrcB = 10 ALUOp = 00 MemRead IorD = 1 MemWrite IorD = 1 RegDst = 1 RegWrite MemtoReg = 0 RegDst = 0 RegWrite MemtoReg = 1 PCWrite PCSource = 10 ALUSrcA = 1 ALUSrcB = 00 ALUOp = 01 PCWriteCond PCSource = 01 Instruction decode/ register fetch Instruction fetch 0 1 Start (Op = 'LW ') o r (O p = 'SW ') (O p = R- typ e) (O p = 'B E Q ') (O p = 'J ') Jump completion Memory read completon step R-type completion Memory access Memory access Execution Branch completion Memory address computation (Op = 'SW ') (O p = 'L W ') Name: 0 M (2) Consider the MIPS implementation shown in Figure 4.65 (page 325) of the textbook.

Assume thatthis implementation is modified by adding to it the ALUSrc MUX, as shown in Figure 4.57 (page 312). Furthermore, this implementation includes the logic described in Slide 7.54. The frequency of the clock signal in this implementation is 400 MHz. The workload executed on this processor requires executing 200,000,000,000 instructions. In this workload, 45% of the instructions are R-type, 22% are lw, 13% are sw, and 20% are beq.

For 33% of the R-type instructions one of the operands is the output of the immediately preceding instruction, which is also an R-type instruction. For 28% of the lw instructions, the instruction that immediately follows the lw is an R-type instruction where one of the operands is the result of the lw instruction. Specify the execution time, in seconds, of the workload. Answer: seconds Show how you derived the answer above. The derivation must start from basic principles.

This requires showing and explaining every step. Do not write anything in this space or below 2 Name: a (3) Consider the MIPS implementation shown in Figure 4.51 (page 304) of the textbook. On this implementation, without any modifications, the following program is executed. Note that the labels il, i2, etc, are not part of the program but you can use them to refer to specific instructions in your explanation. il a d d $ 4 , $ 2 , $ 2 i2 a n d $ 2 , $ 2 , $ 1 i3 s u b $ 5 , $ 2 , $ 7 i4 b e q $ 5 , $ 4 , 0 i5 a d d $ 1 , $ 1 , $ 7 i6 a d d $ 5 , $ 6 , $ 3 i7 s u b $ 4 , $ 4 , $ 3 i8 a d d $ 3 , $ 3 , $ 6 i9 o r $ 0 , $ 6 , $ 3 iJO a n d $ 0 , $ 3 , $ 2 ill a d d $ 0 , $ 5 , $ 5 il2 a d d $ 0 , $ 5 , $ 5 il3 a d d $ 0 , $ 5 , $ 5 il4 a d d $ 0 , $ 5 , $ 5 The second column of the following table provides the values in registers

Ecology 107 Midtermi Hereby Pledge That My Answers On This Exam Are E

Ecology 107 Midterm: I hereby pledge that my answers on this exam are entirely my own, & I only used materials provided by Dr. Kilpatrick in the course. I understand that doing otherwise constitutes cheating. Name:_______________________ See equations on page 5 . 1) The graphs below show the classic research I showed in class by Gause from 1934 were he examined competition between two species of Paramecium .

He started each species off with 5 individuals of in flasks of media alone. He next measured the nutrient use of both species. He found that P. aurelia used 2/3 of the resource that limits P. caudatum populations (nitrogen), whereas P. caudatum used 1.0 times as much of the resource that limit P. aurelia populations (phosphorus) (the different resources limiting Pa and Pc makes competition asymmetric). a) Use this information to construct a “state-space†graph (below). Draw isoclines for the two species using different colors and label them by putting a box around the name with the color for that species (6 pts). Remember that an isocline is a line where the population growth rate, dN/dt, for that species is 0.

The endpoints of the isocline for a hypothetical species 1 (competing with species 2) are K1 and K1/21. The competition coefficient 21 measures the impact (or conversion) of species 2 on (or into) species 1 in terms of the resources that limit species 1 (& vice versa for 12). What are the values of these parameters: (4 pts) Kpa= pcpa= Kpc= papc= b) If we start with 50 Pa and 100 Pc, what will happen? Trace the path of the two populations through the state-space graph: Put a point at 50 Pa and 100 Pc, and move in the appropriate direction based on the isoclines. If you encounter an isocline or one of the axes, re-assess the correct direction.

If you reach the intersection of both lines stop (both species co-exist at equilibrium). If you reach an intersection of an axis and an isocline and the correct direction is to go off the graph into negative space, stop (one species has gone extinct while the other is at equilibrium). Kpc Kpa Kpc/ Kpc/ c) Put a second point at 250 Pa, 100 Pc and repeat the same process as in (b) until you stop again. (4 pts) d) (4 pts) Interpret these results biologically. Can these two species co-exist together or does one go extinct? Does it depend on the starting population sizes? e) At equilibrium, what are the abundances of the two species and which species is more abundant? (2 pts) f) You wanted to grow the two paramecium species as fast as possible to send paramecium to biology classes all across the world.

At what density should you grow them, and how long would this take , starting at a density of 5 (see top figs)? Density Pa (1pt): Day Pa (1pt): Density Pc (1pt): Day Pc (1pt): g) What is the fastest rate you could sustainably harvest each species? Show your work! Maximum harvest Pa (2pts): Maximum harvest Pc (2pts): h) What is the maximum per capita population growth rate, r, for each species? Show your work!

Pop growth rate r Pa (2pts): Pop growth rate r Pc (2pts): 2) An ornithologist studies two populations of birds called song sparrows. One population is migratory and spends winters in Santa Cruz and summers in Alaska. Migration, and variability in the arctic environment make it so that over a long time (decades), a quarter of the time the discrete-time annual population growth rate is 4.0 (good conditions), a quarter of the time is 1.0 (medium), and half the time is 0.5 (bad) (all are based on just females). Amazingly, the other population doesn’t migrate at all, but just lives in British Columbia (B.C.) all year long. There the conditions are more stable and the population growth rate in all years is 1.1. a.

If there were 50 female individuals in each population this year, and conditions in Alaska were those given in the table over the next 5 years, what would the population sizes be (fill in the table)? (5pts) Year B.C. population at beginning of this year Alaska population at beginning of year t Alaska Conditions in year t Now ( Good 1 Bad 2 Bad 3 Medium 4 b. What is the long-term trajectory of these two populations (growing, shrinking, stable) and why (what is the average % growth or decline each year over the long term)? Alaska/Santa Cruz (1pt): British Columbia (2 pts): 3) For this question, use the page with color maps of temperature and precipitation and biomes. a. What is the annual avg temperature, annual precipitation and likely biome at the place indicated by the tip of the arrow in South America?

Temperature (1pt): Precipitation (1pt): Likely Biome (1pt): b. Why is it so cool at this location compared to Paraguay (the small country to the southeast of the arrow that is all in red on the Temperature map) (1pt)? c. Why is it likely so dry at this location compared to areas to the east? Explain. (2 pts) d. If climate change warms this region by 3C, will this change the biome in this location?

Why? (2 pt) 4) a. Use the data in the table to make a plot of the rate of photosynthesis of a plant species versus temperature. Label the axes, plot the points and connect them with a line/curve. (3pts) Temp (C) Rate of Photosynthesis (μmol O2/m2s) b. What range of temperatures does a plant in South America experience, if mean annual temperature at its location is 10C, and there is a 10C difference between the warmest month (January) and coldest month (August), and a 20C difference between the hottest hour of the day (3pm or 15:00 in military time) and coldest hour of the night (5am or 5:00)? On the figure to the left, draw two curves (with different colors), one for the temperature (y-axis) vs time for one day during January and one for one day during August (and label them!).

You may want to figure out what the maximum temperatures are in the hottest month at the hottest hour, and the same for the coldest hour on the coldest day before drawing the temperatures vs time. Put numbers on the y-axis. (4 pts) c. Will 3C of warming increase or decrease photosynthesis by the plant at the location from part 4b? Will the effect be the same across all months and times of the day? Explain. (3 pts) d.

If a plant of this species weighed 150g (including its roots!), calculate the approximate metabolic rate of this plant at the mean annual temperature before and after climate change. Metabolic rate before climate change (2pts): Metabolic rate with +3C warming (2pts): What is the ratio of the metabolic rates (MR), MRafter/MRbefore (1pt): e. Using the figure above, what is the rate of photosynthesis at the mean annual temperature before (10C) and after climate change. Photosynthetic rate before climate change (1 pt): Photosynthetic rate with +3C warming (1 pt): What is the ratio of the photosynthetic rates (PR), PRafter/PRbefore (1 pt): f. For most plants the rate of photosynthesis is about twice the rate of respiration (the metabolic rate).

Will warming be a net benefit or a net cost to the plant, and is the net cost/benefit the same at all times of year and all hours of the day? Explain. (3 pts) g. If the plant grows additional leaves so that it doubles its surface area from 0.10m2 to 0.2m2 and doubles its mass from 150g to 300g, will this make the plant more or less efficient, and by how much? Efficiency is photosynthetic rate for the whole plant/metabolic rate for the whole plant. Remember that the rate of photosynthesis is given in units of O2/m2s, which means that an increase in leaf area (m2) linearly increases the whole plant rate of photosynthesis.

At the average annual temperature, what is the ratio of the metabolic rate of the bigger plant to the smaller plant, and what is the ratio of the photosynthetic rates of the bigger and smaller plant? Ratio of metabolic rates, big/small (2pts): Ratio of photosynthetic rates, big/small (2pts): Is the bigger or smaller plant more efficient and why? (3 pts) h. If the temperature on the leaf surface in the sun reached 30C and the plant wanted to reduce its temperature to more efficiently photosynthesize, what are two ways it could “thermoregulate†(cool down) and what are tradeoffs that might occur if the plant used these strategies? Equations and other information Nt=N0ert; Nt=tN0 if >1, then -1 = % increase per year; if <1, then 1- = % decrease per year. ; K = carrying capacity, r = per capita pop growth rate, MSY = rK/ measures the impact of species 2 on population growth rate of species 1 in terms of the resources that limit species 1, and vice versa for 12.

Adiabatic cooling : -7C for each 1000m of elevation Metabolic rate (in W) = c*M3/4e[-E/(kT)]; where c=e20, M is mass in grams, E is activation energy, 0.63eV, k is Boltzmann’s constant, 8.617x10-5 eV/K; and T is Temperature in K (0C = 273.15K) For Question 3: The maps below show annual precipitation (top), annual average temperature (middle) and likely biomes given temperature and precipitation (bottom). 2 ෠ภචৠè ঠ- = ෠ภචৠè ঠ- = K N K rN K N rN dt dN 1 ෠෠ภචৠৠè ঠ- - = ෠෠ภචৠৠè ঠ+ - = ෠෠ภචৠৠè ঠ- - = ෠෠ภචৠৠè ঠ+ - = ® ® ® ® K N N K N r K N N N r dt dN K N N K N r K N N N r dt dN b b a a 1.cm/yr DensityTime (days)P. aurelia DensityTime (days)P. caudatum P. aurelia P. caudatum Read register 1 Read register 2 Write register Write data Registers ALU Zero Read data 1 Read data 2 Sign extend 16 32 Instruction [31–26] Instruction [25–21] Instruction [20–16] Instruction [15–0] ALU result M u x M u x Shift left 2 Shift left 2 Instruction register PC 0 1 M u x 0 1 M u x 0 1 M u x 0 1 A B M u x ALUOut Instruction [15–0] Memory data register Address Write data Memory MemData 4 Instruction [15–11] PCWriteCond PCWrite IorD MemRead MemWrite MemtoReg IRWrite PCSource ALUOp ALUSrcB ALUSrcA RegWrite RegDst 26 28 Outputs Control Op [5–0] ALU control PC [31–28] Instruction [25-0] Instruction [5–0] Jump address [31–0] Control Hazard detection unit + 4 PC Instruction memory Sign- extend Registers = + Fowarding unit ALU ID/EX MEM/WB EX/MEM WB M EX Shift left 2 IF.Flush IF/ID M u x M u x Data memory WB WBM 0 M u x M u x M u x M u x WB M EX WB M WB M em W rit e PCSrc M em to R eg MemRead Add Address Instruction memory Read register 1 Read register 2 Instruction [15–0] Instruction [20–16] Instruction [15–11] Write register Write data Read data 1 Read data 2 Registers Address Write data Read data Data memory Add Add result ALU ALU result Zero Shift left 2 Sign- extend PC 4 ID/EX IF/ID EX/MEM MEM/WB 16 632 ALU control RegDst ALUOp ALUSrc R eg W rit e In st ru ct io n Branch Control 0 M u x 1 0 M u x M u x M u x MemRead ALUSrcA = 0 IorD = 0 IRWrite ALUSrcB = 01 ALUOp = 00 PCWrite PCSource = 00 ALUSrcA = 0 ALUSrcB = 11 ALUOp = 00 ALUSrcA = 1 ALUSrcB = 00 ALUOp = 10 ALUSrcA = 1 ALUSrcB = 10 ALUOp = 00 MemRead IorD = 1 MemWrite IorD = 1 RegDst = 1 RegWrite MemtoReg = 0 RegDst = 0 RegWrite MemtoReg = 1 PCWrite PCSource = 10 ALUSrcA = 1 ALUSrcB = 00 ALUOp = 01 PCWriteCond PCSource = 01 Instruction decode/ register fetch Instruction fetch 0 1 Start (Op = 'LW ') o r (O p = 'SW ') (O p = R- typ e) (O p = 'B E Q ') (O p = 'J ') Jump completion Memory read completon step R-type completion Memory access Memory access Execution Branch completion Memory address computation (Op = 'SW ') (O p = 'L W ') Name: 0 M (2) Consider the MIPS implementation shown in Figure 4.65 (page 325) of the textbook.

Assume thatthis implementation is modified by adding to it the ALUSrc MUX, as shown in Figure 4.57 (page 312). Furthermore, this implementation includes the logic described in Slide 7.54. The frequency of the clock signal in this implementation is 400 MHz. The workload executed on this processor requires executing 200,000,000,000 instructions. In this workload, 45% of the instructions are R-type, 22% are lw, 13% are sw, and 20% are beq.

For 33% of the R-type instructions one of the operands is the output of the immediately preceding instruction, which is also an R-type instruction. For 28% of the lw instructions, the instruction that immediately follows the lw is an R-type instruction where one of the operands is the result of the lw instruction. Specify the execution time, in seconds, of the workload. Answer: seconds Show how you derived the answer above. The derivation must start from basic principles.

This requires showing and explaining every step. Do not write anything in this space or below 2 Name: a (3) Consider the MIPS implementation shown in Figure 4.51 (page 304) of the textbook. On this implementation, without any modifications, the following program is executed. Note that the labels il, i2, etc, are not part of the program but you can use them to refer to specific instructions in your explanation. il a d d $ 4 , $ 2 , $ 2 i2 a n d $ 2 , $ 2 , $ 1 i3 s u b $ 5 , $ 2 , $ 7 i4 b e q $ 5 , $ 4 , 0 i5 a d d $ 1 , $ 1 , $ 7 i6 a d d $ 5 , $ 6 , $ 3 i7 s u b $ 4 , $ 4 , $ 3 i8 a d d $ 3 , $ 3 , $ 6 i9 o r $ 0 , $ 6 , $ 3 iJO a n d $ 0 , $ 3 , $ 2 ill a d d $ 0 , $ 5 , $ 5 il2 a d d $ 0 , $ 5 , $ 5 il3 a d d $ 0 , $ 5 , $ 5 il4 a d d $ 0 , $ 5 , $ 5 The second column of the following table provides the values in registers $0 through $7 before the execution of this program.

Your task is to provide the "final" values in all those registers, defined as the values four cycles after instruction ilO is fetched. register initial value final value $0 0 $1 7 $2 12 $3 2 $4 22 $5 24 $6 43 $7 3 Explain your answer. Your explanation must include the impact, if any, of the b e q instruction in this program. Do not write anything in this space or below 3 N a m e : a (4) Consider the multicycle MIPS implementation shown in Figures 5.28 and 5.37 of Chap 5, 3 r d E d (pages 323 and 338, slides 5.21 and 5.32). Assume that, in every cycle when a particular control sig n al is logically a don't care, it is actually set to 0. Due to a hardware fault (malfunction), the least-significant bit of ALUSrcB is always one (stuck-at-I).

Except for this specific effect, the circuit operates normally. A) Specify i n full detail what will be the consequences of this fault when the processor executes programs - how will it change the behavior of the processor as observed by a user/programmer who does not know and does not care how the processor is implemented internally? Be sure to clearly identify each and every consequence of this fault with as much detail and specificity as possible. B) Explain your answer to Part A based on the effect of the fault on the operation of the implementation. 4 Name: @) ( 5 ) It is, of course, possible to write a program that writes to memory machine instructions that it then executes.

Such a program is referred to as self-modifying code. Consider the MIPS implementation shown in Figure 4.65 (page 325) of the textbook. Assume that this implementation is modified by adding to it the ALUSrc MUX, as shown in Figure 4.57 (page 312). Furthermore, this implementation includes the logic described in Slide 7.54. A) The specified implementation is capable of executing self-modifying code.

Briefly explain how this can be done. B) With the specified implementation, self-modifying code may not always execute correctly. Explain in detail under what conditions self-modifying code may be executed incorrectly. Your explanation must provide as much detail and specificity as possible. C) Provide a high-level explanation of how the specified implementation must be changed in order to ensure that self-modifying code is always executed correctly.

D) Provide details for how the idea described in Part C can be implemented. Your answer must be in the form of an itemized list, where each item is labeled with a Roman numeral: I) specify any new logic modules (e.g., ALUs, adders, comparators, MUXes, registers) that are needed; II) specify any required modifications to existing modules; III) specify, in detail, how each of the new and/or modified modules are connected and used. 5 Name: 0 (6) Consider the table on Slide 6.16 in the class notes.A) Explain how the compiler can affect the CPI. B) Explain how the ISA can affect the instruction count. C) Explain how the organization can affect the clock rate.

Q . , (7) Consider the multicycle implementation shown in Figure 5.28, page 323, and Figure 5.37, page 338, of Chap 5, 3rd Ed (slides 5.21 and 5.32). During manufacturing, the O input of the PCSource MUX was left disconnected. Unfortunately, it is no longer possible to change the datapath in any way. Fortunately, you can save the day by changing the control unit so that the processor will still execute programs correctly. All you have to do is change the state machine.

A) Explain the basic idea of your modifications in 2-4 clear sentences. B) On the next page is the original state diagram of the control unit. Modify this state diagram to show the required changes. You must make only the minimal changes necessary for correct operation. Any new nodes or edges drawn and any new text written must be in red.

Remember that you can erase whatever you want by placing a borderless white shape over it. Note that, with LibreOffice, it is very easy to change the color of text and various objects. (If necessary, you are permitted to use Google to search of help on how to change colors with LibreOffice ). C) Do your changes affect performance in any way? Your answer must be yes or no. Answer: _ _ _ _ _ _ Explain your answer in detail. 6 Name: Memory read completon step 0 Instruction fetch MemRead ALUSrcA = 0 lorD = 0 IRWrite ALUSrcB = 01 ALUOp = 00 PCWrite 7 Instruction decode/ register fetch Jump completion