Mass Transport in Animals Flashcards
Explain how an arteriole can reduce the blood flow into capillaries
- Muscle contracts;
2. Constricts/narrows arteriole/lumen;
What can you conclude from the appearance of valves in Figure 1 about;
heart muscle activity and blood movement between:
1. ventricles and arteries?
2. atria and ventricles?
(2 marks each)
(Ventricles and arteries) 1. Ventricle (muscles) relaxed OR Arteries recoiled; 2. No (blood) backflow (into ventricles) OR No blood movement to/in/from arteries; (Atria and ventricles) 3. Atria (muscle) contracted; 4. Blood movement from atria (into ventricles);
Which blood vessels carries blood back to the heart at the lowest pressure?
Vena Cava
At P on Figure 3, the pressure in the left ventricle is increasing. At this time, the rate of blood flow has not yet started to increase in the aorta.
Use evidence from Figure 3 to explain why
- Aortic/semi-lunar valves is closed;
2. Because pressure in aorta higher than in ventricle;
Describe and explain the effect of increasing carbon dioxide concentration on the dissociation of oxyhaemoglobin
- Increases/more oxygen dissociation/unloading
OR
Deceases haemoglobin’s affinity for O2; - (By) decreasing (blood) pH/increasing acidity
Use Figure 3 to explain how the seal’s myoglobin dissociation curve shows the seal is adapted for diving.
- High(er) affinity for O2 (than haemoglobin)
OR
Dissociates oxygen less readily
OR
Associates more readily; - Allows (aerobic) respiration when diving/at
low(er) pO2
OR
Provides oxygen when haemoglobin unloaded
OR
Delays anaerobic respiration/lactate production;
Scientists measured the oxygen carrying capacity of seal blood. Theyfoundthehaemoglobinina190kgsealcontained1.07×10 cm oxygen. When the seal dived, it used 5.2 cm3 oxygen per minute per kg of body mass.
Use this information to calculate the maximum number of minutes the seal can remain underwater. Assume that all of the oxygen attached to the haemoglobin is released during the dive.
Correct answer for 2 marks
10.8 to 11 (mins)
OR
10 minutes and 48 seconds = 2 marks;;
Accept for 1 mark, 10.48 minutes
OR
Reference to 2057.7 to 2058 (10 700 ÷ 5.2, time oxygen would last if its mass was 1 kg)
OR
Reference to 56 to 56.3 (10700 ÷ 190, oxygen in 1 kg of seal)
OR
Reference to 988 (5.2 x 190, oxygen used min-1 by the seal)
OR
Incorrect answer with correct answer shown in working
Plot the haemoglobin saturation data in Table 7 and use these points to sketch the fully oxygaemoglobin dissociation curves for a horse and a mouse.
- y axis 0 – 100 in linear scale and x axis minimum 1 to 8 in linear scale and both axes use at least half size of grid;
- Correct plots for 50% and 25% for both animals;
- Both curves levelling off (at higher partial pressures and at percentage saturations ≤100%);
The following equation can be used to estimate the metabolic rate of an animal.
Metabolic rate = 63 × BM–0.27
Use this equation to calculate how many times faster the metabolic rate of a mouse is than the metabolic rate of a horse.
Correct answer of 15 (times faster) = 2marks ;; If ≥3sf given, accept answers in the range 15.0 to 15.4 (times faster) = 2marks;; Incorrect answer 1 mark for evidence of: 23–0.27 divided by 550 000–0.27 OR 0.42888777 OR 0.02819045 OR Between 27 and 27.1 OR Between 1.77599861 and 1.8 OR 0.06
The data in Table 7 show differences between the oxyhaemoglobin dissociation curve for a mouse and the oxyhaemoglobin dissociation curve for a horse.
Suggest how these differences allow the mouse to have a higher metabolic rate than the horse.
- Mouse haemoglobin/Hb has a lower affinity for oxygen
OR
For the same pO2 the mouse haemoglobin/Hb is less saturated
OR
At oxygen concentrations found in tissue mouse haemoglobin/Hb is less saturated; - More oxygen can be dissociated/released/unloaded (for metabolic reactions/respiration);
Mammals such as a mouse and a horse are able to maintain a constant body temperature.
Use your knowledge of surface area to volume ratio to explain the higher metabolic
rate of a mouse compared to a horse.
Mouse
- (Smaller so) larger surface area to volume ratio;
- More/faster heat loss (per gram/in relation to body size);
- (Faster rate of) respiration/metabolism releases heat;
i) Use Figure 1 to give the letter that represents each of these blood vessels
ii) Name the blood vessels that carry blood to the heart muscle.
i) In order : D, G, F
ii) coronary arteries
Answer 4.1 + 4.2 from the photo
4.1) semi-lunar valve: 2,3
atrioventricular valve: 4,1
4.2) 6315.79 to 6400;
Allow one mark for
(SV = 120 – 40 =) 80 (cm3)
OR
(1 cycle = 1.24 – 0.48 =) 0.76 (s)
OR
79 / 80 (beats minute– 1)
Explain the roke of the heart in the formation of tissue fluid.
- Contraction of ventricle(s) produces high blood / hydrostatic pressure;
- (This) forces water (and some dissolved substances) out (of blood capillaries);
Lymphoedema is a swelling in the legs which may be caused by a blockage in the lymphatic system.
Suggest how a blockage in the lymphatic system could cause lymphoedema.
Excess tissue fluid cannot be (re)absorbed / builds up;
Answer 5.1 + 5.2
5.1:
1. First oxygen binds (to Hb) causing change in shape;
2. (Shape change of Hb) allows more O2 to bind (easily) / greater saturation with O2
OR
Cooperative binding;
5.2:
1. (HbA has) lower affinity for O2 at low partial pressures;
OR
(HbA has) lower affinity for oxygen at pp found in tissues;
2. Easier unloading of O2 for (aerobic) respiration;
Answer 5.3
- A large/significant increase in HbF;
- (HbF has) higher affinity for O2 (than faulty HbA);
- Higher proportion of HbF in blood so more oxygen carried;
OR
More oxygen carried after treatment;
Answer 8.4
- (Some) oxygenated blood (from the aorta) flows into pulmonary artery;
OR
Less oxygenated blood flows out through aorta;
OR
Lower blood pressure in aorta; - Less oxygen delivered to cells / tissues / organs / named organ / via named blood vessel;
- So less/not enough oxygen for aerobic respiration (in cell/ tissue/organ);
- Tissue/organ doesn’t grow/develop properly (causing death);
OR
Tissue dies/organ stops working (causing death);
