In a population of birds, there is variation in beak size. Birds with small beaks are better at eating tiny seeds, while birds with large beaks are better at cracking hard, large seeds. Birds with medium-sized beaks, however, struggle to eat either type of seed effectively. Over time, the population begins to show an increase in the number of birds with either small or large beaks, while birds with medium-sized beaks become less common. Which type of selection is being displayed in this scenario?

What is the role of the ribosome in the cell?

Which of the following best describes prokaryotic cells?

What is the term used to describe a child who possesses an allele for a trait but does not express the trait?

What is a shared characteristic of both mitosis and meiosis?  

Which characteristic is unique to eukaryotic cells compared to prokaryotic cells?

Which organisms perform cellular respiration?  

A typical adult female is asked to increase her fundamental frequency from 220 Hz to 330 Hz, and she can easily accomplish this task. When comparing her vocal production at 330 Hz to 220 Hz, we will observe changes in her mean airflow rate and subglottal pressure (Psub). Which of the following statements are true? (Select up to two options; partial credit will be awarded for correct selections.)

Which of the following statements are true about a normal adult’s source? (Select up to two options; partial credit will be awarded for correct selections.)

What structure is the building block of proteins?