Mock MCAT Exam - Biology Flashcards
High levels of carbon dioxide in the blood trigger what body responses?
Increase: Breathing rate, Breathing volume, BP, HR, & Kidney bicarbonate prod (to buffer effects of blood acidosis)
In July, a student tested the soil in two plots and calculated the concentration of nitrogen compounds present in each plot. The student then planted 20 seedlings in the first plot and allowed them to grow. Nothing was planted in the second plot. The student tested the soil in both plots again after one month. The concentration of nitrogen compounds had decreased in the first plot but had remained the same in the second plot. Which of the following best explains the decrease in nitrogen compounds in the first plot?
The nitrogen compounds were absorbed by the seedlings for their growth.
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Facts:
Nitrogen is removed from the soil by crops, gaseous loss, runoff, erosion and leaching. The magnitude and mechanism responsible for nitrogen losses depend upon the chemical and physical properties of a given soil.
In a population of moths, wing color became darker over time. Which of the following is the best evidence that the change in wing color was an evolutionary change?
The frequencies of the alleles for dark wing color in the moth population changed.
Leaves fall from deciduous trees in autumn. The carbon in these leaves is returned to the atmosphere through which of the following processes?
Decomposition
Which of the following statements best explains why geographic isolation can lead to speciation?
Physical separation of populations prevents interbreeding and mixing of gene pools.
Emphysema is a severe respiratory system disease. The disease causes damage that directly prevents the transfer of oxygen to the bloodstream.Which part of the respiratory system does emphysema damage?
Alveoli
Which of the following provides the most conclusive evidence that organisms of two different species share a common ancestor?
They have similar DNA sequences.
In a certain variety of chicken, some offspring have a feather pattern that is black-and-white checkered. Chickens with this checkered feather pattern result from the cross of a black chicken with a white chicken.Which of the following types of inheritance is most likely responsible for the checkered feather pattern?
Polygenic
Polygenic inheritance occurs when one characteristic is controlled by two or more genes. Often the genes are large in quantity but small in effect. Examples of human polygenic inheritance are height, skin color, eye color and weight. Polygenes exist in other organisms, as well.
Ovalbumin is a protein found in eggs. Which of the following best describes the molecular structure of ovalbumin?
A chain of amino acids folded and twisted into a molecule
Blue jays and kingbirds are both classified in the order Passeriformes. In the current taxonomic system, this means that the two types of birds must also belong to the same
Family
