12BIO+Half Yearly+Exam+2010

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STUDENT NAME:

CLASS:

TEACHER (circle): Chandler / Jang / Vella

HSC BIOLOGY

Half-Yearly Examination 2010

Instructions:

Reading Time – 5 minutes.

Working Time – 2 hours.

Write using blue or black pen.

Draw diagrams using pencil.

Board-approved calculators may be used.

Write your name, class and teacher‟s name at the top of every page, in the space

provided.

Total Marks – 100 marks

Section 1 – Pages 2 to 8

Total marks – 20 marks (Multiple Choice). Attempt all questions 1 to 20 and write your answer

on the separate Multiple Choice Answer Sheet provided.

Allow about 30 minutes for this section.

Section 2 – Pages 9 to 20

Total marks – 80 marks. Attempt all questions 21 to 34. Write your answers in the spaces

provided.

Allow about 1.5 hours for this section.



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STUDENT NAME:

CLASS:


HSC BIOLOGY


MULTIPLE CHOICE ANSWER SHEET

SECTION 1 – Total marks (20)

Attempt all questions 1 to 20 and allow about 30 minutes for this section.

Select the alternative A, B, C or D that best answers the question and indicate your choice with a

cross (X) in the appropriate space on the grid below.

Question No.: A B C D

1

2

3

4

5

67

8

9

10

11

12

13

14

1516

17

18

19

20



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SECTION 1 – MULTIPLE CHOICE QUESTIONS.

Total marks (20)

Attempt all questions 1 to 20 and allow about 30 minutes for this section.

Select the alternative A, B, C or D that best answers the question and indicate your choice with a

cross (X) in the appropriate space in the grid on the separate, Multiple Choice Answer Sheet.

1. Which of the following enzymes would work best in the acidic environment of the

stomach?

Enzyme Optimum pH

(A) Amylase 6.7 – 7.5

(B) Pepsin 1.5 – 2.0

(C) Lipase 7.0 - 8.0(D) Catalase 9.0

2. Why is the removal of carbon dioxide from living things important?

(A) Carbon dioxide creates tiny bubbles that damage cell membranes.

(B) Carbon dioxide dissolves in blood plasma to form bicarbonate ions which lower the pH.

(C) Carbon dioxide is a gas which can expand and cause cells to burst.

(D) Carbon dioxide dissolves in the cell cytoplasm to form toxic carbonic acid which

damages cells.

3. Estuarine organisms, such as marine worms and mussels, must cope with changes in the

salt concentrations in their surroundings from low to high tide. To cope with this, the salt

concentration of their body fluids changes with their environment. Which term describes

this process?

(A) Homeostasis

(B) Homozygous

(C) Enantiostasis

(D) Heterozygous

4. What are the main nitrogenous waste products excreted by animals in general?(A) ammonia, uric acid and nitrates

(B) uric acid, urea and urine(C) ammonia, uric acid and urea

(D) urine, nitrates and ammonia



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5. What is a role of the kidney in the excretory system of mammals?

(A) To remove salt from the body and to keep water in the body

(B) To remove water from the body and to keep salt in the body(C) To remove nitrogenous waste from the body and to maintain water levels in the body

(D) To remove water from the body and to maintain levels of nitrogenous substances in the

body

6. Which alternative best describes what happens to oxygen and carbon dioxide as blood

travels through the lungs and muscles?

LUNG MUSCLE

(A) Oxygen dissolves in blood Carbon dioxide dissolves in blood

(B) Oxygen binds strongly tohaemoglobin

Carbon dioxide binds strongly to haemoglobin

(C) Oxygen binds strongly tohaemoglobin

Carbon dioxide dissolves in blood

(D) Carbon dioxide binds weakly to

haemoglobin

Oxygen binds weakly to haemoglobin

7. Amylase is an enzyme that catalyses the breakdown of starch. As the temperature rises, the

activity of this enzyme will

(A) increase until the enzyme begins to denature(B) decrease until the substrate begins to denature

(C) increase until the optimum pH level is reached

(D) decrease until the substrate reaches a maximum concentration

8. Which blood vessels in humans contain structures that allow blood to flow in only one

direction?

(A) Arteries(B) Capillaries

(C) Lymph Vessels

(D) Veins

9. Which scientist‟s work on inheritance in fruit flies led to our understanding of sex-linkage?

(A) Gregor Mendel

(B) James Watson(C) Rosalind Franklin

(D) Thomas Hunt Morgan

10. How are new alleles formed?(A) By crossing over during meiosis

(B) By cloning a new variety in a population

(C) By mutation in the DNA of a gene(D) By production of a new phenotype from the same DNA



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11. What finding from the study of comparative embryology supports the theory of evolution?

(A) Embryos are easily fossilised

(B) The embryos of fish and mammals look very similar (C) The dominant chromosomes are passed on to embryos

(D) Mutation in gametes is common and this leads to different embryos

12. What would be the immediate effect of an increase in the secretion of antidiuretic hormone(ADH) in the bloodstream of a mammal?

(A) Increased levels of potassium ions

(B) Decreased blood pressure and more dilute urine(C) Decreased levels of sodium ions

(D) Increased blood pressure and more concentrated urine

13. A student conducted an experiment where carbon dioxide was bubbled through water. Thestudent recorded the pH meter reading every 5 seconds:

Time (seconds) pH meter reading 5 7.5

10 7.2

15 7.0

20 6.8

What would be the most valid conclusion the student would draw from these results?

(A) The change in pH was too small to be significant(B) The water became less acidic as the amount of CO2 in the water increased

(C) The water became more acidic as the amount of CO2 in the water increased

(D) The change in pH might not be related to the CO2 being bubbled through the water

14. Some students carried out investigations to determine whether a newly discovered animal

was an ectotherm or an endotherm. Each student made one observation and conclusion.

Which is the correct conclusion based on the observation?

Observation Conclusion

(A) It was not a mammal. The animal is an ectotherm.

(B) Its body temperature was 37°C. The animal is an endotherm.

(C) Its temperature was less than the

temperature of the cage

The animal is an endotherm.

(D) Its temperature and metabolism

increased when the cage temperatureincreased.

The animal is an ectotherm.



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15. The diagram below shows one example of enzyme action as demonstrated by the „Lock and

Key‟ model:

Which part of the diagram represents the substrate?

16. The table below represents a monohybrid cross between two pea plants (genotypes Rr andrr). The allele for round (R) is dominant. The allele for wrinkled (r) is recessive.

alleles r R

R

R

What is the expected ratio of phenotypes in the resulting offspring of this cross?(A) All wrinkled peas

(B) 3 round : 1 wrinkled

(C) 1 round : 1 wrinkled

(D) All round peas



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17. Scientists have found that more closely related species have greater similarity in

cytochrome C amino acid sequences. Comparisons like this allow scientists to observe

evolutionary relationships between different organisms.

cytochrome C evolution

Organism Number of amino acid differences from

humansChimpanzee 0

Rhesus Monkey 1

Rabbit 9

Cow 10

Pigeon 12

Bullfrog 20

Fruit Fly 24

Wheat Germ 37

Yeast 42

Using the „cytochrome C‟ information, which organism is most closely related to humans?

(A) Chimpanzee(B) Rhesus Monkey

(C) Rabbit

(D) Yeast

18. Observe the following image:

What process is represented above?

(A) Chromosomes and doubling

(B) Chromosomes are being pulled apart

(C) Independent Assortment

(D) Crossing Over

19. In humans, brown eye colour is dominant and blue eye colour is recessive. A brown-eyed boy and a blue-eyed girl have a blue-eyed mother. What eye colour does the father have

and why?

(A) Brown, because the gene for brown eye colour is sex-linked.(B) Brown, because at least one of the parents must have brown eyes.

(C) Blue, because at least two other members of the family have blue eyes.

(D) Blue, because at least one of the parents must be heterozygous for eye colour.



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20. In a particular sex-linked disease, progressive weakening of the muscles and loss of

coordination lead to death before the age of five.

Using this pedigree, what is the genotype of the individuals numbered 1, 2 and 3?

I ndividual 1 I ndividual 2 I ndividual 3

(A) Normal Normal Normal

(B) Carrier Normal Carrier

(C) Normal Carrier Normal

(D) Normal Carrier Carrier

* * * End of Section 1 * * *



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STUDENT NAME:

CLASS:


HSC BIOLOGY


SECTION 2 – Total marks (80)

Attempt all questions 21 to 34 and allow about 1.5 hours for this section. Write your answers in

the spaces provided.

Question 21 (3 marks)

Why is genetic variation important in the survival of a species? 3



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The diagram shows a representation of a mammalian nephron.

(a) Filtration happens at A. Name TWO blood components that remain in the blood vesselafter filtration. 2

(b) Most reabsorption happens at B. Explain why BOTH passive and active transport are

needed for this process to occur. 2

(c) ADH (anti-diuretic hormone) acts at C. Outline the role of ADH in regulating water

balance. 2



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(a) What is haemoglobin? 1

(b) Describe ONE adaptive advantage of haemoglobin. 2


“All mutations are harmful”. Discuss this statement. 3

Question 25 (3 marks) 3

Identify 3 products extracted from donated blood.



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Explain how hormone activity maintains water and salt levels in the blood. 5

Question 27 (10 marks) 10

The diagram shows two steps of the process of meiosis occurring in a cell with four

chromosomes.

(a) Describe the behaviour of the chromosomes between the steps shown. 2



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(b) List FOUR possible combinations of alleles that would be found in the gametes resulting

from this process. 4

(c) Explain ONE advantage of the process of meiosis to the species. 2

(d) Distinguish between the terms allele and gene. 2


(a) Label the TWO components of phloem tissue indicated in the diagram. 2



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(b) Describe ONE theory about the processes responsible for the movement of materials

through phloem tissue. 3


A plant breeder replicated on of Mendel‟s pea plant breeding experiments. The results of the

cross between green (G) and yellow (g) pods are shown in the table.

Generation Pod colour

Green (G) Yell ow (g)

F 1 632 0

F 2 1560 482

(a) List all possible genotypes of the F 2 generation. 1

(b) Using your understanding of current genetic thinking, interpret the results of the F 2 cross

depicted above. 3



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(c) Describe the features of TWO experimental techniques used by Mendel that led to his

success. 3


Construct a table to distinguish between the environmental conditions experienced by marine and

fresh water fish , and the resulting urine production of each fish. 7



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In rabbits, black (B) coat colour is dominant over white (b) coat colour. Construct a Punnet

Square to correctly represent a cross between a rabbit heterozygous for coat colour and a white

rabbit. 3


As part of an independent research project, a student studied a genetic condition suffered by

members of his family. The student wrote the following summary:

I am male and I have the condition.

My mother does not have the condition.

My father and his brother have the condition.

My father‟s sister and my father‟s mother do not have the condition.

My father‟s father has the condition.

(a) Construct a pedigree of this family. 5



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(b) Why are diagrams, such as pedigrees, useful in analysing data? 1

(c) The student made the following conclusion from his study: 2

“As only males have the condition, it must be a sex-linked condition.”

Assess the validity of the student‟s conclusion, and provide support for your assessment.



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The data in the table are the results from an investigation measuring enzyme activity using

different substrate concentrations. The experiment was carried out at pH9.3 and the temperature

was kept constant at 37°C.

Tube Number Substrate Concentration

(µM)

Enzyme activity

(µM/sec/g)

1 0 0

2 5 0.7

3 10 1.7

4 15 2.5

5 20 3.1

6 25 3.4

7 30 3.98 35 4.1

9 40 4.2

10 45 4.3

An appropriate graph is to be drawn and used to predict the enzyme activity for a substrate

concentration of 75µM.



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(a) Use the data to draw an appropriate graph. 7

(b) Extrapolate your graph and predict what the enzyme activity would be if the substrate

concentration were increased to 75 µM. 2



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Most offspring resemble their parents in a number of characteristics, but there are often some

characteristics in the offspring that are unexpected.

Explain, using examples, how genetics and the environment can affect the phenotype of individuals. 8

* * * End of Examination * * *

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12BIO+Half Yearly+Exam+2010