*Question*
Q: Where do carrier proteins carry ions or molecules? Read this paragraph and choose the correct option from the provided answers: A carrier protein is a transport protein that is specific for an ion, molecule, or group of substances. Carrier proteins "carry" the ion or molecule across the membrane by changing shape after the binding of the ion or molecule. Carrier proteins are involved in passive and active transport. A model of a channel protein and carrier proteins is shown in Figure below . Choices: - between nuclei - across isotopes - back to nucleus - across the membrane A:
**Answer**
across the membrane

*Question*
Q: What regulates the cell cycle only when they are tightly bound to cdks? Read this paragraph and choose the correct option from the provided answers: Cyclins regulate the cell cycle only when they are tightly bound to Cdks. To be fully active, the Cdk/cyclin complex must also be phosphorylated in specific locations. Like all kinases, Cdks are enzymes (kinases) that phosphorylate other proteins. Phosphorylation activates the protein by changing its shape. The proteins phosphorylated by Cdks are involved in advancing the cell to the next phase. (Figure 10.12). The levels of Cdk proteins are relatively stable throughout the cell cycle; however, the concentrations of cyclin fluctuate and determine when Cdk/cyclin complexes form. The different cyclins and Cdks bind at specific points in the cell cycle and thus regulate different checkpoints. Choices: - kinases - subclades - hormones - cyclins A:
**Answer**
cyclins

*Question*
Q: The structure of the human tail bone is called what? Read this paragraph and choose the correct option from the provided answers: The majority of human genes have two or more possible alleles , which are alternative forms of a gene. Differences in alleles account for the considerable genetic variation among people. In fact, most human genetic variation is the result of differences in individual DNA bases within alleles. Choices: - a abnormal structure - a vital structure - an artifact - a vestigial structure A:
**Answer**
a vestigial structure

*Question*
Q: What external feature in human beings is responsible for balance? Read this paragraph and choose the correct option from the provided answers: The ears are also responsible for the sense of balance. Balance is the ability to sense and maintain body position. The semicircular canals inside the ear (see Figure above ) contain fluid that moves when the head changes position. Tiny hairs lining the semicircular canals sense movement of the fluid. In response, they send nerve impulses to the vestibular nerve, which carries the impulses to the brain. The brain interprets the impulses and sends messages to the peripheral nervous system. This system maintains the body's balance by triggering contractions of skeletal muscles as needed. Choices: - tails - brain - hands - ears A:
**Answer**
ears