Biology Midterm 2025

Front

What happens to the proportion of organisms with an advantageous heritable trait over time?

Back

It tends to increase

Answer explanation

According to SCI.9-12.HS-LS4-3, advantageous heritable traits increase an organism's fitness, leading to a higher proportion of these traits in the population over time. Thus, the correct answer is that it tends to increase.

Front

Suppose a population of beetles has a heritable trait that makes some beetles less visible to predators. Using concepts of statistics and probability, explain what is likely to happen to the proportion of beetles with this trait over several generations.

Back

The proportion will likely increase as these beetles survive and reproduce more.

Answer explanation

The proportion of beetles with the heritable trait will likely increase over generations, as these less visible beetles are more likely to survive predation and reproduce, passing on the trait to their offspring.

Front

If a scientist is studying an organism that cannot reproduce on its own and must infect another living cell to multiply, which term should they use to describe it?

Back

Virus

Answer explanation

A virus is an organism that cannot reproduce independently and requires a host cell to multiply. Bacteria can reproduce on their own, while 'trait' and 'coronary artery disease' are not relevant to this context.

Front

A doctor explains to a patient that their heart disease is caused by plaque buildup, restricting blood flow. Based on evidence, what specific disease is the doctor referring to?

Back

Coronary Artery Disease

Answer explanation

The doctor refers to Coronary Artery Disease, which is characterized by plaque buildup in the coronary arteries, leading to restricted blood flow to the heart. This condition is a common cause of heart disease.

Front

What is a specific, observable characteristic of an organism called?

Back

Trait

Answer explanation

A specific, observable characteristic of an organism is called a 'trait'. Traits can include physical features, behaviors, and other attributes that can be measured or observed.

Front

Which type of organism requires a host to reproduce?

Back

Virus

Answer explanation

Living organisms, such as plants and animals, can reproduce independently without a host. In contrast, viruses and parasites require a host to reproduce, while bacteria can reproduce on their own but are not classified as living organisms in the same way.

Front

What is the process used to maintain homeostasis in which a change in the body causes more of that action to occur in a feedback loop?

Back

Positive feedback

Answer explanation

Positive feedback is a process where a change in the body triggers further changes in the same direction, enhancing the action. This is different from negative feedback, which counteracts changes to maintain stability.

Front

What is the term for the number of organisms an environment can support?

Back

Carrying capacity

Answer explanation

The term 'carrying capacity' refers to the maximum number of organisms an environment can sustainably support. It is a key concept in ecology that helps understand population dynamics.

Front

Which heart condition is primarily caused by the narrowing of arteries due to fatty deposits, leading to reduced oxygen supply to the heart muscle?

Back

Coronary artery disease

Answer explanation

Coronary artery disease is caused by the narrowing of arteries due to fatty deposits, which reduces oxygen supply to the heart muscle. This condition directly affects heart function, making it the correct choice.

Front

Grace starts with one bacteria cell in a petri dish. After some time, the cell divides, producing two new bacteria cells. Later, those two bacteria cells divide into four. This type of growth is called

Back

exponential growth

Answer explanation

The growth of bacteria from one cell to two, then four, demonstrates exponential growth, where the population doubles at regular intervals. This is characteristic of exponential growth, not limited, logarithmic, or extrapolated growth.