General Function Behavior - Sets of Real Numbers and the Cartesian Coordinate Plane

1.1 Sets of Real Numbers and the Cartesian Coordinate Plane

1.6.1 General Function Behavior

My Sister’s Keeper is a novel by Jodi Picoult, published in 2004. The book, which was made into a fi lm in 2009, follows the life of 13-year-old Anna, who enlists the help of an attorney to sue her parents for rights to her own body. Anna’s older sister Kate suff ers from leukemia and Anna was conceived through IVF to be a genetic match and donor for her sister. Anna donates bone marrow and blood for her sister throughout her life. As Kate’s condition worsens, their parents want Anna to donate a kidney to Kate after she goes into renal failure, but Anna fi les a lawsuit against her parents for medical emancipation from them despite the consequences for her sister’s health.

This novel is a fi ctional story but already there have been real examples of children being conceived by IVF and born to provide stem cells for siblings who would otherwise die.

Questions to consider

1 Should IVF conceptions such as Anna’s be permitted?

2 Who should have rights over a child’s genetic material in cases like this?

3 Is it right that a child should be created simply to keep another person alive?

6 HUMAN HEALTH AND PHYSIOLOGY 1 165 4 Which of the following statements is correct?

A During breathing in, the rib cage moves up and out and the pressure inside the thorax increases.

B Alveoli are small sac-like structures that have walls only two cells thick.

C To assist with breathing out, the abdominal and external intercostal muscles contract.

D The purpose of ventilation is to increase the rate of gas exchange in the alveoli. (1)

5 Which of the following statements is correct?

A In a motor neuron, the impulse travels from the axon to the cell body.

B A nerve impulse travels from a receptor to the CNS via a sensory neuron and from the CNS to an eff ector via a motor neuron.

C The endocrine system produces hormones, which pass from the endocrine glands to the blood through ducts.

D The resting potential is divided into two parts, depolarisation and repolarisation. (1)

6 Which of the following statements is correct?

A In the male reproductive system, the sperm ducts are connected to the ureters.

B During the process of in vitro fertilisation, a woman is injected with FSH to stimulate egg cells to mature.

C FSH and oestrogen are hormones released from the ovaries whereas LH and progesterone are hormones released from the pituitary gland.

D In the menstrual cycle, the levels of progesterone begin to rise around day 5. (1)

7 Outline the functions of the stomach, small intestine and large intestine in a table like the one below. (4)

Stomach Small intestine Large intestine

provides acidic environment provides weakly alkaline environment

8 Explain the relationship between the structure and function of arteries, veins and capillaries. (9)

9 Explain antibody production. (3)

10 Explain how the skin and mucous membranes prevent entry of pathogens into the body. (3) 11 Explain how blood glucose concentration is controlled in humans. (8) 12 Discuss the ethical issues of in vitro fertilisation (IVF) in humans. (8)

13 The body mass index (BMI) takes into account the weight and height of a person and can be used to determine if a person is overweight or obese. The nomogram shows the body mass index for a range of weights and heights.

a State the weight description of a 75 kg man who is 145 cm tall. (1) b A woman of height 150 cm has a BMI of 40. Calculate the minimum weight she must lose to be

considered ‘normal’. (1)

c Outline the relationship between height and BMI for a fi xed weight. (1) (total 3 marks)

source: adapted with permission from the American College of Neuropsychopharmacology (ACNP), from G Bray, Obesity, Fat intake and Chronic Disease, (2000)

Height/cm Weight/kg

Body Mass Index

125 130 135 140 50

40 30

Very obese 145

Obese Overweight Normal Underweight

150 155 160 165 170 175 180 185 190 195 200 205 210 30

25 35 40 45 50 55 60 65 70 7580 8590 10095 110 120 130 140 150

6 HUMAN HEALTH AND PHYSIOLOGY 1 167

source: Hans R. Widmer et al., ‘Working underground: respiratory adaptations in the blind mole rat’ PNAS (4 March 1997), vol. 94, issue 4, pp. 2062–2067, Fig 1, © 2003 National Academy of Sciences, USA

Relative values / %

Features important to oxygen uptake 160

140 120 100 80 60 40

0 20

volumeLung Alveolar

area Capillary

area Key

White rats Blind mole rats

14 Blind mole rats (Spalax ehrenberghi) are adapted to live in underground burrows with very low oxygen conditions. Scientists compared blind mole rats and white rats in order to determine whether these adaptations are due to changes in their ventilation system.

Both types of rat were placed on a treadmill and the amount of oxygen consumed was measured at diff erent speeds. This study was done under normal oxygen conditions and under low oxygen conditions.

The results are shown in the scatter graphs below.

a Compare the oxygen consumption of blind mole rats and white rats when the treadmill is not moving. (1) b Compare the eff ect of increasing the treadmill speed on the oxygen consumption in both types of rats

under normal oxygen conditions. (3)

c Evaluate the eff ect of reducing the amount of oxygen available on both types of rat. (2) The lungs of both types of rats were studied and the features important to oxygen uptake were compared.

The results are shown in the bar chart below.

Oxygen consumption / cm3s–1kg–1

Treadmill speed / ms^–1 Blind mole rats

1.6 1.4 1.2 1.0 0.8 0.6 0.4

0.20.0 0.2 0.4 0.6 0.8 1.0 1.2

Oxygen consumption / cm3s–1kg–1

Treadmill speed / ms^–1 normal oxygen low oxygen White rats

Key 1.6 1.4 1.2 1.0 0.8 0.6 0.4

0.20.0 0.2 0.4 0.6 0.8 1.0 1.2

d Using your knowledge of gas exchange in lungs, explain how these adaptations would help the

blind mole rats to survive in underground burrows. (3)

(total 9 marks)

15 Near the middle of pregnancy in humans, the placenta begins to secrete a hormone called corticotrophin-releasing hormone (CRH). CRH infl uences the production of hormones that stimulate the development of the fetus.

A study was carried out to determine if levels of CRH were correlated with the timing of the baby’s delivery. Blood samples were taken from 500 women during their pregnancies and the concentration of CRH was measured. The women were then divided into three groups according to whether their baby was delivered prematurely, at full-term or late.

The graph below shows how the concentration of CRH varied in the mothers’ blood (maternal blood) in each of the three groups during pregnancy.

source: R Smith, Scientific American (March 1999) pp. 68–75

Maternal CRH concentration / pmol dm–3 plasma 0 10 20 30 40 50 60 70 80 90 100

15 20

Time since start of pregnancy / weeks

25 30

Key

Women who delivered prematurely Women who delivered at full-term Women who delivered late

a Outline how the concentration of CRH in the blood changes during the pregnancies of women who

delivered prematurely. (2)

b Compare how the concentration of CRH changes during the pregnancies of women who delivered

late with those that delivered at full-term. (2)

c Measure the diff erence in CRH concentration at 30 weeks between the women who delivered

prematurely and those that delivered at full-term. (1)

d Suggest how knowledge of the CRH concentration in maternal blood might be used by doctors

monitoring pregnancies. (2)

The Western spadefoot toad (Scaphiopus hammondii) lives in desert areas in California and lays its eggs in pools formed by rain. When the egg fi rst hatches, its body form is referred to as the tadpole stage. At some point, it undergoes metamorphosis (a change in body form) to develop into the adult toad.

If the pools where the eggs have been laid shrink due to a lack of rain, the tadpoles quickly develop into small adult toads. If there is suffi cient rain and the pools persist, the tadpoles develop more slowly and grow large before developing into adult toads.

e Suggest how undergoing metamorphosis at diff erent times in response to water levels helps the survival

of the toad. (3)

It has been suggested that CRH control of development might have evolved in amphibians long before mammals appeared. In toads, increase in CRH concentration leads directly to an increase in the level of the hormone thyroxine and indirectly to an increase in corticosterone levels.

6 HUMAN HEALTH AND PHYSIOLOGY 1 169 An experiment was carried out to determine what hormones might be involved in triggering

development in response to pond drying. Tadpoles were raised in a constant high-water-level

environment. They were then divided into two groups. One group was transferred to a tank containing 10 dm³ of water – a high-water environment. The other group was transferred to a tank of the same size containing only 1 dm³ of water – a low-water environment. The concentrations of thyroxine and corticosterone were measured in each group. The results are shown below.

source: R J Denver, General and Comparative Endocrinology, (1998), 110, pp. 326–336

0 High water environment Thyroxine concentration/ ng g–1 body mass

Low water environment Thyroxine

4 3 2

0 1

High water environment Corticosterone concentration/ ng g–1 body mass

Low water environment Corticosterone

f Compare the concentrations of thyroxine and corticosterone in the two groups. (2) g Predict how the concentration of CRH would be diff erent in the two groups. (1) (total 13 marks)

In document College Algebra (Page 110-124)