Organisms adapt according to their environment and needs through the process of natural selection. Beaks of birds are especially adapted to a specific diet and lifestyle. The following images are beaks belonging to birds that are found in the Philippines. Which beak belongs to a grain-eating bird?
Specific types of hormones are produced and released by the different organs of the body. Which of the following hormones is therefore incorrectly paired to its organ of production?
The electrocardiogram shows the electrical impulses from the heart following depolarization of the sinoatrial node and conduction of the impulse through the Purkinje fibers. Which of the following ECG readings describe an arrhythmia or abnormal heart rhythms?
Reference: Ribeiro AH, Ribeiro MH, Paixão GM, Oliveira DM, Gomes PR, Canazart JA, Ferreira MP, Andersson CR, Macfarlane PW, Meira Jr W, Schön TB. Automatic diagnosis of the 12-lead ECG using a deep neural network. Nature Communications. 2020 Apr 9;11(1):1–9. https://doi.org/10.1038/s41467-020-15432-4
Editorial review: compare the patterns and explain the limits of interpreting these source images.
SARS-CoV-2 vaccines train the adaptive immune response of the body against the viral infection. Which of the following blood cells functions in the adaptive immune response?
Biofuels are sources of energy from renewable sources. One example is bioethanol, which is ethanol sourced from fermentation of plant products. In one experiment, 1.00 g of liquid ethanol was found to burn with 2.08 g of gaseous oxygen. Like most hydrocarbons, this combustion process produces water and gaseous carbon dioxide. What is the expected total mass of the products from this reaction?
The table below shows the properties of some objects.
I. cork; Solid wood; 0.15 g/mL; Flammable at high temperatures
II. pea; Solid seed; 0.6 g/mL; Edible
III. Key chain; Solid metal; 5.3 g/mL; Melts at high temperatures
IV. Credit card; Solid plastic; 0.9 g/mL; Melts at high temperatures
Which of them would float on isopropyl alcohol, which has a density of 0.79 g/mL?
Rice is a staple not only in the Philippines but in most south-east Asian countries as well. It is typically washed well before cooking. Rice is typically added with the same volume of water. Once the water starts to boil at 100 °C, it is advised to lower the heat, while maintaining the boiling, until the rice cooks. What happens to the temperature while the water is boiling?
Image: gran, own work, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=10216705
A container ship left Manila Bay at 5:00 am. The following graph shows the distance it traveled over time. When is the acceleration of the ship LOWEST?
Editorial convention: use the quantity actually labeled on the vertical axis and assume straight-line motion.
Aside from the capital Manila, two other major cities in the Philippines are Cebu and Davao. It is possible to travel between these two cities by a combination of land and sea travel. One may take a 6-hour bus running at 50 km/hr from Davao city to Agora, Cagayan de Oro. Then, a ferry boat running at 27.8 km/hr from this port to Cebu would take 9 hours. What is the average speed of this trip from Davao to Cebu?
Editorial convention: neglect transfer time and round to the nearest whole km/h.
This area, which is considered to be in the driest place on earth in general, has portions that have not seen flowing water for millions of years. Where is it located?
