Data-based questions Flashcards
(Hummingbirds have long narrow beaks that adapt them to collecting nectar from flowers. Nectar provides energy in the form of sugar, but has very low concentrations of amino acids and protein. Therefore, hummingbirds have to supplement their diet by catching flying insects. They do this by flying with their beaks wide open towards insects. Scientists have used high-speed video to study the success rate for catching insects. The pie charts below show the results, according to which part of the beak the insect touches first.)
State the relationship between the part of the beak that insects first touch and the success rate.
The nearer to the base the insect touches, the higher the success rate.
(State the relationship between the part of the beak that insects first touch and the success rate.)
Suggest a reason for the relationship in (a) (i).
Difficult to manipulate insect at tip of long narrow beak;
Beak wider open near tip;
Base of beak is nearer the esophagus/throat/mouth;
More difficult to escape if insect near base / easier to hold near base.
(Birds that feed only on flying insects have a different shape of beak from hummingbirds.)
Predict, with a reason, the shape of beak in a species of bird that feeds only on flying insects.
shape:
short / wide
(accept “thick”);
reason:
wide beak gives greater chance of catching insect / less chance of losing it;
larger area for catching insect with wider beak;
Very rapid wing beats keep a hummingbird’s body steady near a flower while it collects nectar. This unusual type of flight behaviour is called hovering. Measurements were taken to investigate hovering in four hummingbird species. The body mass and maximum frequency of wing beats were measured. The velocity of the wing tips was measured when the wings were beating at their maximum frequency. The mean results are shown in the table below.
State the relationship between body mass and maximum frequency of wing beats.
Lower wing beat frequency with greater body mass /
inverse relationship /
negative correlation
The data in the table indicates that there is a similar maximum velocity for wing tip movement whatever the overall size of the bird.
Suggest one problem that would be caused by a velocity of wing tip movement greater
than this.
damage to wing / feathers / joints;
excessive energy requirement / muscles not strong enough;
loss of stability / harder to control hovering;
(Hummingbirds are the smallest birds in the world, with adult masses ranging from approximately 2g to 20g.)
Using the data in the table, suggest a reason why hummingbirds with a mass larger than
20 g have not evolved.
Wing beat frequency limited by maximum wing tip velocity (of 16 m s−1 );
Wing beat frequency would be too low for hovering;
Explain why the volume taken in per hour was higher at 10°C than at the higher temperatures.
rapid heat loss at lower temperatures;
energy from sugar; used to maintain constant (body) temperature.
Suggest one reason for the higher overall concentration of nitrogenous waste products in urine at 40 °C.
Smaller volume of water ingested (therefore smaller volume of urine / more concentrated urine);
Loss of water by panting / evaporation (therefore smaller volume of urine / more concentrated urine);
The ratio between the concentration of ammonia and the concentration of uric acid in the urine of hummingbirds changes as the temperature rises. The ratio at 10 °C is 4.4:1.
Calculate the ratio between the concentration of ammonia and the concentration of
uric acid at 40 °C.
1.625 : 1
(accept 1.6 : 1)
(accept 1.64 : 1)
The ratio between the concentration of ammonia and the concentration of uric acid in the urine of hummingbirds changes as the temperature rises. The ratio at 10 °C is 4.4:1.
Explain the difference in the relative amounts of ammonia and uric acid at 10 °C and at 40 °C.
higher ammonia concentrations (more than 7.8) would be toxic;
more ammonia converted to uric acid at higher temperatures;
less water for urine production/more water used for cooling;
Hummingbirds use energy at a faster rate than any other bird or mammal.
Explain two reasons for the high rate of energy use in hummingbirds.
high energy cost of hovering;
high rate of loss of body heat due to high surface area to volume ratio;
Compare the acidity of rain in urban and rural areas.
both moderately acidic / rural slightly more acidic /
urban slightly less acidic
Compare the levels of atmospheric pollution in urban and rural areas.
urban areas have overall more atmospheric pollution (or converse);
levels of each pollutant are much higher concentrations in urban areas;
Outline the conclusions that can be drawn about the growth of Populus deltoides from the data in the bar chart.
overall growth was greater in urban areas;
greater growth in urban areas below ground;
greater growth above ground;
above ground growth always greater than below ground growth;
Discuss whether the differences in growth rates of Populus deltoides between urban and rural areas could be due to differences in the acidity of rain.
Unlikely to be cause because differences in pH are small
