Biology Unit 1 Mark Scheme

Unit B1, B1.1 Mark scheme
Keeping healthy
1. (i) or (ii) the loop is sterilised accept to kill anything on the loop to kill any bacteria on it; do not credit to clean the loop if hot it would kill bacteria picked up (from culture); accept ‘microorganisms’ or ‘microbes’ accept entry of contaminated air but reject entry of air unqualified to prevent entry (from the air) of unwanted bacteria or bacterial spores or fungal spores; accept so can’t breath on it; accept ‘microorganisms’ or ‘microbes’ so that the (petri) dish is not opened (after bacteria are cultured) or to reduce evaporation or drying of the agar, accept ‘microorganisms’ or ‘microbes’ accept to prevent anything relevant getting in/out reject references to spillage 1 1

(iii)

1

(iv)

1

[4] 2. (a) (b) being overweight do not accept fat unqualified; allow BMI over 25 (i) rose by 8% / from 16% to 24% / by 50% / rapidly then more slowly (ii) any two reasonable suggestions e.g. less active accept e.g.s like fewer jobs / more cars / less physically demanding employment OWTTE more food / take-aways / fast food (c) (i) high (blood) cholesterol do not accept combination of 2 labels ignore references to LDL and HDL answer in range 8-17 inclusive some deaths related to more than one factor 1 1 1 1 2

(ii) (iii)

1 1 [8]

3.

(a)

any two from: • age • gender • mass • number in group • time any two from: • highest (mean) mass loss on Rosemary Conley or Rosemary Conley most effective • least (mean) mass loss in control group or mean

2

(b)

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Unit B1, B1.1 Mark scheme
(c) (Atkins) costs least mass loss very similar to other diets or second highest mass loss or as effective as other diets any two from: • (exercise) increases metabolic rate / respiration ignore sweating • (exercise) needs / uses energy / calories allow burns fat / calories do not accept energy for respiration • (this) energy comes from food / fat • less food / energy/ calories converted to fat 1