Hbio Sem 1 Revision

Multiple Choice
Identify the choice that best completes the statement or answers the question.

____	1	Which of the following is the most suitable hypothesis?
A	If the rate of exercise is increased, then the rate of blood flow to the kidneys will decrease.	
B	If the rate of exercise is increased or the type of exercise is changed, then the rate of blood flow to the kidneys will decrease.	
C	Does the rate of blood flow to the kidneys change with the rate of exercise?	
D	If the rate of exercise is increased the rate of blood flow changes.	

____	2	The following hypothesis was tested.
If the rate of sun exposure in a population increases, then the incidence of skin cancers in that population will increase.
The independent variable is the:
A	intensity of the sun’s ultraviolet radiation.	
B	incidence of skin cancers in the population.	
C	rate of sun exposure in the population.	
D	average age of the population.	

____	3	The following hypothesis was tested.
If the rate of sun exposure in a population increases, then the incidence of skin cancers in that population will increase.
The dependent variable is the:
A	average age of the population.	
B	rate of sun exposure in the population.	
C	intensity of the sun’s ultraviolet radiation.	
D	incidence of skin cancers in the population.	

____	4	In timing a subject’s breathing rate, experimental error can be reduced by:
A	using a digital stopwatch that records to thousandths of a second.	
B	repeating the measurements and obtaining the average of the results.	
C	recording the results in a table.	
D	waiting until the subject is ready.	

____	5	Which of the following is NOT a principle of ethical behaviour in investigating humans?
A	The investigation is of benefit to the participants.	
B	The investigation has voluntary participation.	
C	The participants have given their consent.	
D	The participants remain anonymous.	

____	6	In order for a placebo to be effective in a drug trial, it should be:
A	undetectable by the participants.	
B	made obvious to the participants.	
C	of a different appearance to the drug being trialled.	
D	another type of drug shown to be effective in the desired treatment.	

____	7	In designing an investigation researching the effect of exercise on muscle growth, researchers applied a number of principles to ensure ethical standards. Which set of the following principles would be UNLIKELY to be accepted by an ethics committee?
A	All participants are assisted in the weight training exercises to minimise injury and are given lessons in using weights.	
B	Participants are not told what the purpose of the study is to ensure it does not affect results.	
C	All participants’ individual results are kept anonymous by using codes rather than names.	
D	All participants volunteer to be part of the study and give consent in writing.	

____	8	In designing an investigation researching the efficacy of a potential new oral contraceptive, researchers set up a trial whereby one group of participants are given a placebo and another group are given the test contraceptive. Which of the following will ADD to the validity of the investigation?
A	Ensuring the placebo group are informed that they will not receive the contraceptive and obtaining their consent in writing	
B	Adding a group who were not given the test contraceptive or the placebo	
C	Advising the placebo group to use alternate contraceptive methods to ensure the participants do not become pregnant	
D	Encourage more participants by informing them of the potential benefits of the new contraceptive	

____	9	Which of the following describes a suitable double-blind experiment investigating an antibiotic treatment for chlamydia?
A	Both the researchers and the subjects know which individuals are being tested with the new antibiotic.	
B	The researchers but not the subjects know which individuals are being tested with the new antibiotic.	
C	Neither the researchers nor the subjects know which individuals are being tested with the new antibiotic.	
D	The subjects but not the researchers know which individuals are being tested with the new antibiotic.	

____	10	Researchers obtained data on blood flow through muscles at various rates of exercise as measured by the power (Watts) produced while riding on a stationary cycle. The data ranged from 80W to 400W.
The data could best be represented by which of the following graphs?
A	A histogram where blood flow is on the horizontal axis and power is on the vertical axis.	
B	A column graph where power is on the horizontal axis and blood flow on the vertical axis.	
C	A line graph where blood flow is on the horizontal axis and power is on the vertical axis.	
D	A line graph where power is on the horizontal axis and blood flow on the vertical axis.	

____	11	If a cube-shaped cell with sides measuring 15 µm were to have its sides doubled in length, its volume would increase:
A	4 times and its surface area by 4 times.	
B	2 times and its surface area by 2 times.	
C	8 times and its surface area by 8 times.	
D	8 times and its surface area by 4 times.	

____	12	Goblet cells are found in the lining of the intestines and are a source of mucin, a gel-like protein substance. What organelles are likely to be particularly prominent in the goblet cells?
A	Flagella	
B	Cilia	
C	Golgi bodies	
D	Mitochondria	

____	13	Mitochondria and the endoplasmic reticulum share the following property. They:
A	both connect to the nuclear membrane.	
B	are both membranous structures.	
C	both connect to the cell membrane.	
D	both release energy for the cell to use in making new substances.	

____	14	Which of the following statements is correct?
A	Chromosomes are made of DNA and are found in the cell nucleus.	
B	The cell nucleus is made of DNA and found within chromosomes.	
C	DNA is made of chromosomes and found in the cell nucleus.	
D	The nucleus is made of chromosomes and stored in DNA.	

____	15	Some of the reactions of cellular respiration occur at the inner membrane of the mitochondria.
A feature of mitochondria that facilitates this is the:
A	elongated shape of mitochondria.	
B	folding of the inner membrane.	
C	distribution of mitochondria throughout the cell.	
D	digestive enzymes that mitochondria contain.	

____	16	The main advantage of cells being small is that:
A	many cells can work together to perform a common function.	
B	many more cells can fit into a body.	
C	they have a large surface area relative to their contents.	
D	they fit closer together in the body.	

____	17	When examining the size of human cells, a large person, compared with a small person, would be expected to have:
A	an equivalent number of cells of a larger size.	
B	fewer cells of a similar size.	
C	an equivalent number of cells of a similar size.	
D	more cells of a similar size.	

____	18	Which of the following statements is correct?
A	Cytoplasm contains the cell membrane and is made of cytosol.	
B	Cytosol contains the cytoplasm.	
C	The cell membrane is found in the cytoplasm and is made of cytosol.	
D	The cell membrane encloses the cytoplasm.	

____	19	Nuclear pores in the nuclear membrane:
A	allow large molecules to enter and leave the nucleus.	
B	provide a surface for chemical reactions.	
C	provide a location for amino acids to be joined together to make peptides.	
D	allow gases to be exchanged.	

____	20	Inside a cell, what is the network of channels formed by parallel membranes?
A	The nucleus	
B	The endoplasmic reticulum	
C	Ribosomes	
D	The mitochondria	

____	21	From the outside to the inside of a cell, the correct sequence of layers is:
A	extracellular fluid, hydrophilic heads of phospholipids, hydrophobic tails of phospholipids, cytoplasm.	
B	extracellular fluid, hydrophilic heads of phospholipids, hydrophobic tails of phospholipids, hydrophilic heads of phospholipids, cytoplasm.	
C	extracellular fluid, hydrophobic tails of phospholipids, hydrophilic heads of phospholipids, hydrophobic tails of phospholipids, cytoplasm.	
D	cytoplasm, hydrophilic heads of phospholipids, hydrophobic tails of phospholipids, hydrophilic heads of phospholipids, extracellular fluid.	

____	22	Which of the following is NOT a function of the cell membrane?
A	Cellular respiration	
B	Acting as a physical barrier	
C	Regulation of the passage of materials	
D	Support for the whole cell	

____	23	Diffusion within cells:
A	is facilitated by microtubules within the cell.	
B	only occurs across the cell membrane.	
C	accounts for most of the movement of molecules and ions.	
D	occurs only between the endoplasmic reticulum and the Golgi body.	

____	24	Channel proteins are important to the cell’s function because:
A	they allow small molecules that are not soluble in the membrane lipids to diffuse in and out of the cell.	
B	they are the only way large molecules can pass through the phospholipid layers.	
C	they are required for lipid-soluble molecules to pass through the membrane.	
D	they prevent osmosis.	

____	25	Diffusion gradients are increased by:
A	increasing distance and decreasing concentration differences.	
B	increasing distance and increasing concentration differences.	
C	decreasing distance and decreasing concentration differences.	
D	decreasing distance and increasing concentration differences.	

____	26	Osmosis will occur when there is a:
A	difference in concentration of sugar on either side of a permeable membrane.	
B	diffusion gradient.	
C	differentially permeable membrane.	
D	differentially permeable membrane and a diffusion gradient.	

____	27	Active transport:
A	does not require the expenditure of energy.	
B	can move molecules or ions from a lower to a higher concentration.	
C	requires a concentration gradient.	
D	only works to bring required substances into a cell.	

____	28	Vesicular transport is a form of active transport because:
A	secretions exported by the cell in vesicles require energy to be manufactured.	
B	it occurs only when there is a concentration gradient.	
C	energy from the cell is required to form vesicles.	
D	it is a form of cytosis.	

____	29	Diffusion is a random process and occurs because:
A	dissolved molecules experience more collisions the greater the distance over which the diffusion takes place.	
B	dissolved molecules are always equally distributed.	
C	dissolved molecules experience fewer collisions further away from high concentrations.	
D	net diffusion ensures the dissolved molecules move towards the higher concentration.	

____	30	Facilitated diffusion is a form of passive transport because:
A	it relies on a concentration gradient.	
B	energy is required to change the shape of the carrier protein.	
C	carriers can become saturated.	
D	carrier proteins are specific.	

____	31	Cell differentiation and specialisation mean that:
A	different cells have different specialties.	
B	no two cells are the same.	
C	from just one cell, many types of cells with their own structures and functions are produced.	
D	each cell belongs to a particular tissue.	

____	32	Organs:
A	each belong to one body system only.	
B	can be part of more than one body system.	
C	contain just one type of tissue.	
D	work independently of other organs.	

____	33	Epithelial tissue typically forms a smooth surface because its cells:
A	fit very closely together.	
B	are column shaped.	
C	are thin and flat.	
D	are surrounded by an extensive non-cellular matrix.	

____	34	A feature of connective tissue that relates to its role in supporting the body is that the cells:
A	are separated from each other by large amounts of non-cellular material.	
B	are bound close together.	
C	cover important organs.	
D	contract to keep shape.	

____	35	Which of the following statements about skeletal muscle is correct? It is:
A	striated and contracts voluntarily.	
B	non-striated and contracts involuntarily.	
C	non-striated and contracts voluntarily.	
D	striated and contracts involuntarily.	

____	36	Which system is primarily responsible for taking in oxygen and removing carbon dioxide?
A	The circulatory system	
B	The respiratory system	
C	The nervous system	
D	The digestive system	

____	37	Organs are always made up of:
A	one type of cell carrying out a particular function.	
B	one type of tissue that carries out a particular function.	
C	two or more types of tissue working together to carry out a particular function.	
D	smaller organs working together to carry out a particular function.	

____	38	Cells:
A	can be categorised into approximately 20 types.	
B	are arranged with others of the same type to form organs.	
C	belong to tissues with specific tasks.	
D	are mainly arranged in a disorganised mass.	

____	39	Which of the following is NOT an organ?
A	Heart	
B	Stomach	
C	Epithelium	
D	Brain	

____	40	Body systems:
A	each have one organ.	
B	work in isolation to make a functioning organism.	
C	each have one specific function.	
D	work together to produce a functioning organism.	

____	41	Cellular respiration differs from breathing in that:
A	breathing rate is variable while cellular respiration is always constant.	
B	breathing is required at all times while cellular respiration occurs only when required.	
C	cellular respiration produces glucose and carbon dioxide but breathing produces oxygen.	
D	cellular respiration is a chemical process occurring inside cells but breathing is the movement of air in and out of the lungs.	

____	42	Most of the energy released from the breakdown of glucose to carbon dioxide during cellular respiration is in the form of:
A	chemical bonds in water.	
B	chemical bonds in ATP.	
C	movement of cellular organelles.	
D	heat.	

____	43	Enzymes:
A	provide energy for important reactions.	
B	work independently of pH.	
C	increase the activation energy of a reaction.	
D	are temperature dependent for their activity.	

____	44	Which of the following is a correct description of some types of metabolic reaction?
A	Catabolic reactions break down molecules into smaller ones and release energy.	
B	Anabolic reactions break down molecules into smaller ones and release energy.	
C	Catabolic reactions build molecules into larger ones and release energy.	
D	Anabolic reactions build molecules into larger ones and release energy.	

____	45	Which of the following is a correct statement about cellular respiration?
A	Anaerobic respiration occurs within mitochondria and can produce 2 ATP per glucose molecule.	
B	Aerobic respiration occurs within mitochondria and can produce 36 ATP per glucose molecule.	
C	Aerobic respiration occurs within the cytoplasm and can produce 2 ATP per glucose molecule.	
D	Anaerobic respiration occurs within cytoplasm and can produce 36 ATP per glucose molecule.	

____	46	Enzymes are specific in that:
A	they are found only in some cell types.	
B	they can only combine with specific substrates.	
C	they are sensitive to particular pH levels.	
D	temperature influences their activity.	

____	47	Without enzymes, cellular respiration would:
A	occur at a rate too fast for cells to maintain.	
B	not occur at a rate high enough to sustain life.	
C	result in less ATP produced.	
D	be reversed.	

____	48	Chemical energy in ATP can be used for:
A	heat absorption, organelle movement and the transmission of nerve impulses.	
B	catabolism, cell division and cell growth.	
C	anabolism, cell movement and active transport.	
D	passive transport, maintaining cell organisation and releasing heat.	

____	49	Proteins have two very different but important roles in the body. These are as both:
A	polysaccharides and enzymes.	
B	structural materials and genetic information.	
C	structural materials and enzymes.	
D	hereditary information and enzymes.	

____	50	During high rates of anaerobic respiration, lactic acid builds up in a cell’s cytosol. One consequence of this would be:
A	the enzyme converting pyruvic acid to lactic acid would become less effective.	
B	more oxygen would become available.	
C	the enzymes of the citric acid cycle would be inhibited.	
D	glycolysis would be increased.	

____	51	Some chemotherapy drugs are toxic to bone marrow cells that produce white blood cells.
A likely consequence of treatment with such drugs would be:
A	enhanced oxygen carrying capacity of blood.	
B	reduced resistance to microorganisms invading the body.	
C	changed blood pH.	
D	more oxyhaemoglobin and less haemoglobin.	

____	52	Sickle cell disease is a genetic disease that results in a change in the shape and flexibility of red blood cells.
A likely consequence of this disease would be:
A	an increased life span of the red blood cells.	
B	greater exchange of oxygen by the red blood cells.	
C	inhibited blood flow.	
D	increased oxygen carrying capacity of blood.	

____	53	Which of the following statements describes the diffusion of oxygen following a concentration gradient?
A	From a high oxygen concentration in body cells to a high concentration in red blood cells.	
B	From a high oxygen concentration in body cells to a low concentration in red blood cells.	
C	From a low oxygen concentration in lungs to a high concentration in red blood cells.	
D	From a high oxygen concentration in lungs to a low concentration in red blood cells.	

____	54	An increase in the rate of cellular respiration will lead to:
A	an increase in the concentration of hydrogen ions in the blood.	
B	a decrease in the concentration of hydrogen ions in the blood.	
C	an increase in the concentration of oxyhaemoglobin in red blood cells.	
D	a decrease in the concentration of carbon dioxide dissolved in plasma.	

____	55	Initiating vigorous exercise will result in:
A	no change in heart rate and an increase in stroke volume.	
B	an increase in heart rate and an increase in stroke volume.	
C	an increase in heart rate and no change in stroke volume.	
D	an increase in heart rate and a decrease in stroke volume.	

____	56	Snake venom contains toxic proteins that are normally too large to pass into blood vessels from intercellular fluid. Most snake bite treatments are designed to ensure lymphatic flow is not increased.
Which of the following would lead to an increase in lymphatic flow and thus is NOT recommended as first aid treatment for snake bite?
A	Applying a splint to immobilise the bitten limb	
B	Moving the bitten limb to increase blood flow	
C	Applying a pressure bandage to the area around the snake bite	
D	Keeping the patient calm	

____	57	Which of the following plasma transfusions is able to be successful?
A	Donor: Type B; Recipient: Type O	
B	Donor: Type A; Recipient: Type B	
C	Donor: Type B; Recipient: Type AB	
D	Donor: Type O; Recipient: Type AB	

____	58	A banned form of doping used in sports is ‘blood doping’. In blood doping, athletes receive blood transfusions, usually of their own stored blood. A transfusion of this nature should improve an athlete’s performance because it:
A	increases the number of circulating red blood cells and therefore the oxygen-carrying capacity of the blood.	
B	balances the pH of the athlete’s blood by adding blood with little lactic acid in it.	
C	allows more carbon dioxide to be carried in the plasma.	
D	reduces the blood pressure and increases the heart rate of the athlete.	

____	59	Why is the human circulatory system considered a double circulatory system?
A	Each side of the heart has two chambers: an atrium and a ventricle.	
B	Each side of the heart receives blood from and pumps blood to different locations.	
C	Half of the body’s blood is oxygenated, and the other half is not.	
D	The heart rate can double in response to exercise.	

____	60	The ventricles have string-like tendons that attach to the ventricular muscle. These tendons:
A	ensure that the heartbeat makes the correct sound.	
B	prevent atrioventricular valves being pushed out by the pressure of contraction.	
C	filter out unwanted particles from the blood.	
D	direct blood flow away from the atria.	

____	61	Which of the following is NOT a feature of alveoli contributing to the efficient exchange of gases?
A	Thin walls	
B	Moist surfaces	
C	Lined by smooth muscle	
D	Small and numerous	

____	62	Pleurisy is an inflammation of the pleural membranes that causes them to rub against one another. A likely consequence of this would be:
A	slower breathing rate.	
B	slower heart rate.	
C	shallow breathing.	
D	greater contraction of intercostal muscles.	

____	63	Which of the following correctly shows the sequence of actions that occur during inspiration?
A	Intercostal muscles contract  diaphragm contracts  epiglottis opens	
B	Intercostal muscles relax  diaphragm contracts  epiglottis closes	
C	Intercostal muscles contract  diaphragm relaxes  epiglottis opens	
D	Intercostal muscles contract  diaphragm relaxes  epiglottis closes	

____	64	Nitrogen gas makes up about 79% of atmospheric air and can be safely breathed in. However, care must be taken in work situations where nitrogen may be released in closed environments, such as in transporting and storing liquid nitrogen. Why is it necessary to exercise care in such situations?
A	Additional nitrogen in the air will be at the expense of water vapour, which is needed to keep alveoli moist.	
B	At high concentrations nitrogen becomes toxic.	
C	Lungs can only expire a limited amount of nitrogen at any time.	
D	If the nitrogen concentration in air is too high, then the oxygen concentration gradient between air and blood will be too low.	

____	65	Emphysema’s greatest effect occurs as a result of:
A	a reduction in total surface area available for gas exchange.	
B	reduced flexibility of alveoli.	
C	extra energy being required to breathe.	
D	reduced blood flow to the lungs.	

____	66	Asthma is potentially fatal because it can:
A	make it painful to breathe.	
B	lead to inadequate oxygenation of blood.	
C	mean some foods cannot be eaten.	
D	prevent some sufferers from exercising adequately.	

____	67	Tobacco smoking can lead to the development of lung cancer. However, the smoke itself also has an effect, and can cause:
A	greater amounts of expiration.	
B	the breakdown of alveoli.	
C	alveoli becoming blocked with unwanted oxygen.	
D	a tightening of the larynx.	

____	68	Which of the following will lead to a greater oxygen concentration gradient between alveolar air and blood?
A	Holding the breath	
B	Reducing the volume of air a patient is allowed to inspire with each breath	
C	Treating a patient with medicinal oxygen delivered by a face mask	
D	Restricting air flow, such as with asthma	

____	69	Some acute brain injuries lead to the cessation of involuntary breathing. What would an immediate consequence of this be?
A	Greater carbon dioxide flow from the blood to the air in the alveoli	
B	Constriction of the alveoli	
C	Reduced oxygen flow from the air in the alveoli to the blood	
D	A slowing of blood flow through the lungs	

____	70	During exercise, the concentration gradient of carbon dioxide between the blood and the air in the alveoli is maintained by:
A	increasing blood flow and increasing breathing rate.	
B	decreasing breath volume and increasing breathing rate.	
C	decreasing breath volume and decreasing breathing rate.	
D	increasing blood flow and decreasing breathing rate.	

____	71	The digestive system primarily carries out the:
A	exchange of metabolites.	
B	excretion of wastes.	
C	breaking down of food and absorption of nutrients.	
D	production of essential nutrients.	

____	72	Blockages of the bile duct can lead to difficulties in the digestion of which of the following food types?
A	Fibre	
B	Sugars	
C	Fats	
D	Starch	

____	73	Chemical digestion is completed through the action of:
A	bile.	
B	acids.	
C	enzymes.	
D	mucous.	

____	74	Mechanical digestion in the stomach occurs as a result of:
A	layers of muscle causing contractions.	
B	hydrochloric acid killing bacteria.	
C	production of amylase enzymes.	
D	peristalsis.	

____	75	Which is the correct match of tooth type and function?
A	Incisors cutting, canines crushing and molars cutting	
B	Incisors tearing, canines crushing and molars cutting	
C	Incisors tearing, canines cutting and molars crushing	
D	Incisors cutting, canines tearing and molars crushing	

____	76	Peristalsis refers to the:
A	movement of food from the pharynx into the oesophagus.	
B	lubrication of the oesophagus by mucus.	
C	movement of food down the oesophagus by gravity.	
D	waves of constriction of the muscles of the oesophagus.	

____	77	Which of the following does NOT account for a relatively large number of capillaries in the small intestine? The need for:
A	respiration to produce digestive enzymes.	
B	respiration to undertake active transport.	
C	transport of nutrients to the rest of the body.	
D	respiration to enable smooth muscle contraction.	

____	78	The large intestine absorbs:
A	undigested cellulose.	
B	water.	
C	bacteria.	
D	sugars.	

____	79	Coeliac disease can lead to deficiencies in certain nutrients, such as iron. This is because:
A	sufferers are unable to eat wheat, rye or barley.	
B	muscle cramping uses up iron.	
C	damaged villi are less able to absorb nutrients.	
D	the immune system rejects nutrients.	

____	80	Which of the following increases the rate of food moving through the alimentary canal?
A	Eating a large meal	
B	Exercise	
C	Eating a meal with a high percentage of protein	
D	Eating a meal with little fibre	

____	81	Which of the following will increase urine production?
A	A large intake of water	
B	A low-protein diet	
C	A high-salt diet	
D	Vigorous exercise	

____	82	Which of the following is the correct order the passage of urea in the kidney?
A	Renal artery ® efferent arteriole ® glomerulus ® glomerular capsule ® collecting duct ® renal tubule	
B	Renal artery ® afferent arteriole ® glomerulus ® glomerular capsule ® renal tubule ® collecting duct	
C	Renal artery ® afferent arteriole ® glomerular capsule ® glomerulus ® renal tubule ® collecting duct	
D	Renal artery ® afferent arteriole ® glomerulus ® glomerular capsule ® efferent arteriole ® renal tubule ® collecting duct	

____	83	Which of the following shows the correct order for the passage of glucose in the kidney?
A	Renal artery ® afferent arteriole ® peritubular capillary ® glomerular capsule ® glomerulus ®  tubule ® vein	
B	Renal artery ® efferent arteriole ® glomerulus ® glomerular capsule ® peritubular capillary ® tubule ® vein	
C	Renal artery ® afferent arteriole ® glomerulus ® glomerular capsule ® tubule ® peritubular capillary ® vein	
D	Renal artery ® peritubular capillary ® afferent arteriole ® glomerular capsule ® glomerulus ® vein ® tubule	

____	84	Only approximately 20% of the plasma present in the capillaries of the glomerulus is filtered. Which feature of the kidneys ensures that they are effective in excreting wastes regardless?
A	The large number of nephrons in the kidney	
B	The high percentage of reabsorption in the nephron	
C	The large volume of urine produced	
D	The large size of the glomerulus	

____	85	Which of the following facilitates fluid being filtered out of the blood?
A	Kidney stones blocking collecting ducts.	
B	The efferent arteriole having a smaller diameter than the afferent arteriole.	
C	Tubules having a large surface area.	
D	Tubular secretions adding materials to the filtrate.	

____	86	Which of the following is NOT typically found in the urine of a healthy person?
A	Water	
B	Urea	
C	Glucose	
D	Creatine	

____	87	Which of the following circumstances would lead to an increase in reabsorption?
A	A low-salt diet	
B	The presence of glucose in the renal tubules	
C	Excessive water consumption	
D	Dehydration	

____	88	The source of urea in urine is the:
A	conversion of ammonia.	
B	synthesis of proteins.	
C	breakdown of purines.	
D	breakdown of creatine.	

____	89	Ammonia is a product of:
A	the breakdown of nucleic acids.	
B	urea production.	
C	the catabolism of creatine phosphate.	
D	protein metabolism.	

____	90	Which of the following should be avoided to reduce the risk of kidney failure?
A	Maintaining a healthy weight	
B	Water	
C	Smoking	
D	Performance-enhancing drugs	

Hbio Sem 1 Revision
Answer Section

MULTIPLE CHOICE

	1	ANS:	A
It is an ‘If, then’ statement. B has more than one idea to be tested. C is a question. D does not present a relationship as specific as A.

PTS:	1	REF:	17

	2	ANS:	C
The independent variable matches the ‘If’ component of the hypothesis. Rate of sun exposure is the independent variable because it is the factor being investigated and, according to the hypothesis, incidence of skin cancer depends on sun exposure.

PTS:	1	REF:	18

	3	ANS:	D
The dependent variable matches the ‘then’ component of the hypothesis. According to the hypothesis incidence of skin cancer depends on sun exposure.

PTS:	1	REF:	18

	4	ANS:	B
Repetition will decrease random error. The stopwatch will increase precision but not reduce error. Waiting for the subject will introduce a possible systematic error – that is, influence of the subject.

PTS:	1	REF:	19

	5	ANS:	A
Investigations cannot always be of benefit to all the participants.

PTS:	1	REF:	19

	6	ANS:	A
Placebos can only be effective if they are unknown to participants.

PTS:	1	REF:	20

	7	ANS:	B
Participants cannot give informed consent if they are unaware of the objectives.

PTS:	1	REF:	19

	8	ANS:	B
A further control group would ensure a comparison can be made to those who may change their behaviour based on taking a contraceptive (or a placebo they believe is a contraceptive).

PTS:	1	REF:	18

	9	ANS:	C
In a double-blind experiment neither the researchers nor the participants should be aware of who receives the treatment and who receives the placebo. This ensures there is no bias.

PTS:	1	REF:	20

	10	ANS:	D	PTS:	1	REF:	21

	11	ANS:	D
Doubling side length increases surface area by 4 times but increases the volume 8 times.

PTS:	1	REF:	34

	12	ANS:	C
Golgi bodies modify proteins and package them for secretion.

PTS:	1	REF:	31

	13	ANS:	B
Mitochondria have a double membrane and the endoplasmic reticulum has pairs of parallel membranes.

PTS:	1	REF:	29

	14	ANS:	A
The nucleus is a cell component, chromosomes are molecular structures, and DNA is a chemical. DNA coils up to form chromosomes. Chromosomes are located in the nucleus (of dividing cells).

PTS:	1	REF:	31

	15	ANS:	B
Folding increases the surface area, allowing more sites for reactions to take place.

PTS:	1	REF:	32

	16	ANS:	C
Large membrane surface area facilitates increased exchange of materials in and out of the cell.

PTS:	1	REF:	33

	17	ANS:	D
Cells need to be small, regardless of the size of the human.

PTS:	1	REF:	33

	18	ANS:	D
Cytoplasm is inside the membrane and the cytosol is the liquid part of the cytoplasm.

PTS:	1	REF:	30

	19	ANS:	A
RNA, a large molecule, needs to leave the nucleus for protein synthesis.

PTS:	1	REF:	30

	20	ANS:	B
The endoplasmic reticulum’s membranes extend throughout the cytoplasm.

PTS:	1	REF:	31

	21	ANS:	B
The phospholipid layer is a bilayer with the hydrophobic tail layers facing each other.

PTS:	1	REF:	41

	22	ANS:	A
Cellular respiration is completed at mitochondrial membranes.

PTS:	1	REF:	42

	23	ANS:	C
Molecules and ions move within the cell mostly by diffusion.

PTS:	1	REF:	48

	24	ANS:	A
The membrane lipids impede the diffusion of water-soluble substances.

PTS:	1	REF:	44

	25	ANS:	D
A short distance and large difference in concentration gives a steep gradient.

PTS:	1	REF:	43, Figure 4.4b	

	26	ANS:	D
Without differential permeability, there would not be osmosis, only diffusion.

PTS:	1	REF:	45

	27	ANS:	B
Active transport requires energy because substances are moved across the membrane against the concentration gradient.

PTS:	1	REF:	46

	28	ANS:	C
Energy is needed to form the vesicles.

PTS:	1	REF:	47

	29	ANS:	C
Molecules moving away from the area of higher concentration hit fewer of the same type of molecule.

PTS:	1	REF:	43

	30	ANS:	A
The change of shape of the carrier protein does not require energy and can only allow molecules to flow in the direction of the concentration gradient.

PTS:	1	REF:	46

	31	ANS:	C
There are more than 200 different types of human cells all originating from the one fertilised egg cell.

PTS:	1	REF:	53

	32	ANS:	B
Some organs are part of more than one system.

PTS:	1	REF:	59

	33	ANS:	A
Because epithelial cells fit very closely together they form a very smooth surface.

PTS:	1	REF:	55

	34	ANS:	A
The non-cellular matrix gives the tissue strength so that it can hold body parts together.

PTS:	1	REF:	56

	35	ANS:	A
Skeletal muscle, the muscle attached to bones, contracts voluntarily and is striated. Smooth muscle is involuntary and non-striated.

PTS:	1	REF:	57

	36	ANS:	B
The main function of the respiratory system is the intake of oxygen and the removal of carbon dioxide.

PTS:	1	REF:	59

	37	ANS:	C
Organs are distinct structures that carry out a particular task; they are made of two or more different tissue types.

PTS:	1	REF:	59

	38	ANS:	C
Cells with similar specialisations that carry out a common function are grouped together into tissues.

PTS:	1	REF:	53

	39	ANS:	C
The epithelium is a tissue.

PTS:	1	REF:	55

	40	ANS:	D
The body systems are all integrated into the organism.

PTS:	1	REF:	53

	41	ANS:	D
Breathing is the inhalation and exhalation of gases whereas cellular respiration is a chemical process occurring inside the cells.

PTS:	1	REF:	67

	42	ANS:	D
Only about 40% of the energy released in respiration is converted to ATP; most is in the form of heat.

PTS:	1	REF:	70

	43	ANS:	D
Temperature influences enzyme activity. Enzymes have ideal pH ranges, decrease activation energy and catalyse reactions without adding energy.

PTS:	1	REF:	66

	44	ANS:	A
Anabolic reactions require energy to build larger molecules while catabolic reactions break down molecules into smaller ones and release energy.

PTS:	1	REF:	63

	45	ANS:	B
Anaerobic respiration occurs in the cytoplasm and can produce 2 ATP while aerobic respiration occurs in the mitochondria and can produce up to 36 molecules of ATP.

PTS:	1	REF:	69

	46	ANS:	B
Each enzyme catalyses only one specific reaction as explained by the lock and key model.

PTS:	1	REF:	66

	47	ANS:	B
Cellular respiration involves many steps each catalysed by enzymes and would occur very slowly without them.

PTS:	1	REF:	69

	48	ANS:	C
Catabolism releases energy and heat absorption and release does not require energy input.

PTS:	1	REF:	70

	49	ANS:	C
DNA holds genetic (hereditary) information and polysaccharides are carbohydrates.

PTS:	1	REF:	65

	50	ANS:	A
The rate of a reaction decreases as the concentration of the products (lactic acid) increases.

PTS:	1	REF:	66

	51	ANS:	B
White blood cells remove invading microorganisms.

PTS:	1	REF:	76

	52	ANS:	C
Red blood cells’ typically biconcave shape and flexibility allows them to flow through small capillaries with minimal resistance. Sickle-shaped cells inhibit blood flow.

PTS:	1	REF:	76

	53	ANS:	D
Oxygen diffuses from the air in the lungs where the concentration is higher into the blood where the concentration is lower.

PTS:	1	REF:	77

	54	ANS:	A
Cellular respiration produces carbon dioxide, which when dissolved in blood forms carbonic acid. The acid then dissociates into hydrogen ions bicarbonate ions.

PTS:	1	REF:	78

	55	ANS:	B
The heart can increase cardiac output by increasing both heart rate and stroke volume.

PTS:	1	REF:	83

	56	ANS:	B
Lymph is pushed along the lymph vessels by the squeezing action of skeletal muscles.

PTS:	1	REF:	86

	57	ANS:	A
O type recipients have both anti-A and anti-B antibodies in their plasma already, so they can receive plasma from any donor.

PTS:	1	REF:	90

	58	ANS:	A
Lactic acid is very short-lived in blood anyway. 
The amount of plasma will not affect the amount of carbon dioxide carried very much.
Adding blood will likely increase, rather than decrease, blood pressure.

PTS:	1	REF:	91

	59	ANS:	B
Blood travels through the heart twice on each cycle through the body and lungs.

PTS:	1	REF:	80

	60	ANS:	B
The edges of the atrioventricular valves are held by tendons to prevent the flaps turning inside out.

PTS:	1	REF:	82

	61	ANS:	C
The alveolus wall is only one cell layer and is moist. Alveoli are small and numerous.

PTS:	1	REF:	100

	62	ANS:	C
The pleura allow the lungs to slide along the chest wall when breathing.

PTS:	1	REF:	98

	63	ANS:	A
The epiglottis must open to allow inflow of air. Contracting the diaphragm pulls it down, thereby increasing lung volume.

PTS:	1	REF:	101

	64	ANS:	D
Nitrogen is inherently non-toxic, but it is dangerous in high concentrations because the oxygen concentration will be low.

PTS:	1	REF:	102

	65	ANS:	A
Gas exchange in humans relies on a very large surface area. Emphysema reduces that area.

PTS:	1	REF:	103

	66	ANS:	B
If gases are not exchanged adequately, the concentration gradient will not be sufficient to allow oxygen to diffuse into blood cells effectively.

PTS:	1	REF:	102

	67	ANS:	B
Inhaling irritating smoke particles can cause damage to the alveoli.

PTS:	1	REF:	103

	68	ANS:	C
A greater percentage of oxygen in inhaled air will increase the concentration gradient.

PTS:	1	REF:	102

	69	ANS:	C
As oxygen is diminished in the alveolar air space, the concentration gradient will drop.

PTS:	1	REF:	102

	70	ANS:	A
An increased breathing rate allows carbon dioxide to be expelled from the lungs faster. An increased blood flow moves more carbon dioxide through the alveolar capillaries.

PTS:	1	REF:	102

	71	ANS:	C
Excretion of wastes is carried out by the excretory system.

PTS:	1	REF:	108

	72	ANS:	C
Bile helps emulsify lipids (fats).

PTS:	1	REF:	113

	73	ANS:	C
Enzymes help break down large molecules that would otherwise be unable to be absorbed.

PTS:	1	REF:	112

	74	ANS:	A
Three layers of muscle in the stomach wall contract to churn the food.

PTS:	1	REF:	111

	75	ANS:	D
Each type of tooth has a different function related to shape and structure, as shown in Figure 9.3: 

PTS:	1	REF:	110

	76	ANS:	D
A wave of constriction of the bands of muscles in the oesophagus is called peristalsis (plural: peristalses).

PTS:	1	REF:	110

	77	ANS:	A
Digestive enzymes are primarily produced in organs other than the small intestine.

PTS:	1	REF:	112

	78	ANS:	B
Cellulose and bacteria cannot be digested. Sugar is not absorbed in the large intestine.

PTS:	1	REF:	116

	79	ANS:	C
Damaged villi have a greatly reduced surface area.

PTS:	1	REF:	118

	80	ANS:	A
A large meal causes greater stretching of the stomach, so that material is pushed into the small intestine more quickly.

PTS:	1	REF:	117

	81	ANS:	A
Exercise will reduce blood flow to the kidneys and increase water loss to sweat. A high-salt diet will cause greater reabsorption of water from the tubules, while a low-protein diet will reduce production of urea and reduce the need for urine production.

PTS:	1	REF:	128

	82	ANS:	B
Blood enters the kidneys through the renal arteries. Each renal corpuscle is supplied by an afferent arteriole leading into a glomerulus. The glomerular capsule begins the nephron, leading into the renal tubule. The tubules of several nephrons join into a collecting duct.

PTS:	1	REF:	126

	83	ANS:	C
Glucose in the blood enters the kidneys through the renal arteries and then flows into a renal corpuscle, which is supplied by an afferent arteriole leading into a glomerulus. Glucose passes into the glomerular capsule as part of the filtrate. It then flows into the tubule where it is reabsorbed into peritubular capillaries that flow into the renal veins.

PTS:	1	REF:	128

	84	ANS:	A
With about 1.2 million nephrons in each kidney, the amount filtered every minute is still quite high.

PTS:	1	REF:	128

	85	ANS:	B
The smaller diameter of the efferent arteriole increases the blood pressure in the glomerulus.

PTS:	1	REF:	126

	86	ANS:	C
Glucose should all be reabsorbed from the tubules and therefore not present in the urine.

PTS:	1	REF:	128

	87	ANS:	D
Dehydration requires more water to be reabsorbed.

PTS:	1	REF:	128

	88	ANS:	A
Liver cells convert toxic ammonia to less toxic urea.

PTS:	1	REF:	124

	89	ANS:	D
The amino group must be removed from proteins when they are metabolised, releasing ammonia.

PTS:	1	REF:	124

	90	ANS:	C
Lack of water can lead to kidney stones. Performance-enhancing drugs, particularly anabolic steroids, can cause scarring inside the kidneys.

PTS:	1	REF:	131