Question 1

A phylogenetic tree

Accepted Answer

A phylogenetic tree is a diagram that shows the evolutionary relationships among different species or groups of organisms. It illustrates the sequence of events in which populations split and evolved into new species, allowing us to trace the history of life on Earth.

Question 2

Refer to the figure below.  Which is demonstrated in this diagram of the tree of life?

Accepted Answer

The figure demonstrates that plants, fungi, and animals share a common eukaryotic ancestor, which indicates that they are all descendants of that ancestor. This is the best choice based on the information provided in the figure. The other choices are not supported by the figure.

Question 3

Refer to the table below.  The table shows a list of symptoms observed in an older domestic cat.The veterinarian observing these symptoms suspects a problem involving the thyroid gland.This gland produces and secretes thyroid hormone.Thyroid hormone is involved in controlling cell metabolism and its use of energy.It also is involved in controlling heart rate, breathing rate, and other organ functions.Should this be a concern to the cat's owner?

Accepted Answer

The observed symptoms suggest a problem with the thyroid gland, which plays a critical role in maintaining the balance of the cat's internal body systems. Without proper thyroid hormone production and secretion, these systems will continue to be out of balance, leading to potentially serious health consequences. Therefore, the cat's owner should be concerned and take the cat to a veterinarian for further evaluation and treatment.

Question 4

Gaucher disease is a genetic disorder in which the cells do not produce an enzyme necessary for breaking down fatty substances.Persons afflicted with Gaucher disease experience severe problems, including swelling, bruising, anemia, neurological problems, and bone abnormalities.Some patients die of the disease.Which statement explains why the lack of an enzyme leads to the problems observed in patients with Gaucher disease?

Accepted Answer

The lack of an enzyme necessary for breaking down fatty substances results in the accumulation of these substances in cells, which can interfere with normal cell functions and cause the observed symptoms in patients with Gaucher disease.

Question 5

Darwin referred to the differential reproductive success of individuals with particular variations as

Accepted Answer

Darwin referred to the differential reproductive success of individuals with particular variations as natural selection. This is the key mechanism behind how evolution occurs, where organisms with advantageous traits are more likely to survive and reproduce, passing on those traits to their offspring.

Question 6

Refer to the figure below.  The figure shows a simple sponge that lives attached to the ocean floor.The sponge consists of an outer layer of epidermal cells, an inner layer of collar cells and amebocytes, and pore cells that allow water to move from the outside to the inside.The water is propelled by the beating of flagella attached to the collar cells on the inside cavity.Collar cells trap food particles that are digested by the amebocytes.A student claims that a simple sponge could be a model organism used to study how multicellular organisms evolved.Which statement best evaluates this student's claim?

Accepted Answer

The student's statement is correct because the sponge demonstrates a simple structure made up of cells that have specialized to serve different functions. Multicellularity is a complex trait that has evolved many times independently in different lineages. Scientists study simple organisms, such as sponges, to understand how multicellularity evolved and how different cell types and functions arose. Sponges have simple body plans and lack organs and other complex structures found in more derived animals, making them a suitable model organism to study multicellularity evolution.

Question 7

Which represents a correct ordering of the levels of complexity at which life is studied, from most simple to most complex?

Accepted Answer

This ordering starts with the most basic unit of life, the cell, and progresses to tissues made up of cells, then organs made up of tissues, organisms made up of organs, populations made up of organisms, and finally communities made up of populations.

Question 8

Homeostasis involves the maintenance of a

Accepted Answer

Homeostasis involves the maintenance of a constant internal environment, including body temperature, pH balance, and nutrient levels. It does not necessarily involve maintaining a constant external environment, as the environment around an organism may fluctuate. The rate of natural selection is not directly related to homeostasis.

Question 9

Refer to the figure below showing the steps carried out in a laboratory using cells obtained from a mouse embryo.  What statement is true based on the experiment depicted in the figure?

Accepted Answer

The figure depicts the process of cells from a mouse embryo going through development into specialized cells that perform different functions. This supports option D, which states that a multicellular organism develops from a group of identical cells into non-identical specialized cells that perform different functions. Options A, B, and C are not supported by the experiment depicted in the figure. Option E is partially true, as cells can be reprogrammed to a certain extent, but the end result is still a specialized cell with a specific function.

Question 10

Which statement is true?

Accepted Answer

Sexual selection and genetic drift are two important mechanisms of evolution that can lead to the diversification of life. These mechanisms can cause genetic differences to accumulate within populations, which can eventually result in the formation of new species.

Answer: None of the other answer choices are true. 
 A is incorrect because the diversity of life has also depended on unique historical events, such as mass extinctions and geographic isolation. C is incorrect because Earth is estimated to be around 4.5 billion years old, and has gone through numerous changes over that time. D is incorrect because the ancestral forms of life were vastly different from modern organisms, and have evolved over billions of years. E is incorrect because while all life shares a common ancestor, there is significant genetic variation between different groups of organisms.

Question 11

Relationships between living organisms can best be gleaned by comparing

Accepted Answer

Comparing the genomes of living organisms can reveal their evolutionary relationships because organisms with more similar DNA sequences are more closely related. This is because these similarities likely arose due to a common ancestor. Comparing anatomical features or embryological development can also be used to infer evolutionary relationships, but these characteristics can be more variable and subjective. The fossil record can provide information about the past history of organisms, but it may not give insight into their current relationships.

Question 12

Sea squirts are marine organisms that have a simple bag-like body structure.The sea squirt draws water through slits in its body into the body interior.It filters food from the moving water and squirts the water along with waste materials through an opening in its body.What is likely true about the sea squirt's body cells?

Accepted Answer

Sea squirts have specialized cells that perform different functions depending on their location, with internal cells often specialized for filtering and processing food, and external cells likely involved in protection and intake, demonstrating a division of labor within the organism.

Question 13

A key point in Darwin's explanation of evolution is that

Accepted Answer

Darwin's theory of natural selection asserts that any trait that provides even a slight advantage in survival and reproduction will be favored and passed on to future generations. This process leads to the gradual accumulation of favorable traits within a population, eventually resulting in evolution.

Question 14

Suppose that multicellular life had never evolved on Earth.Which characteristic would be absent in the life forms observed today in that case?

Accepted Answer

The absence of multicellular life means that there would be no complex organisms with specialized cells and tissues. Therefore, nervous systems, which require specialized cells and tissues to function properly, would be absent in the life forms observed today. Options A, B, C, and D are all possible in unicellular organisms or simple multicellular organisms.

Question 15

The Eukarya include all of the following except

Accepted Answer

The Eukarya domain includes plants, fungi, animals, and protists. Archaea are a separate domain from Eukarya.

Question 16

Suppose that you are working in a research lab investigating the nature of multicellularity.Which evidence could you gather from two different types of cells obtained from an adult multicellular animal to show that they are specialized?

Accepted Answer

Differences in genes being expressed would indicate that the two types of cells have specialized functions. Different genes being expressed would correspond to different proteins being produced, allowing each cell type to perform its specific role.

Therefore, options A, B, D, and E are incorrect as they do not directly relate to the specialization of cells. While cells with different functions may exhibit differences in nutrient uptake, protein synthesis, DNA content, and waste buildup, these traits are not unique to specialized cells.

Question 17

Evolution is

Accepted Answer

Evolution refers to the change in the genetic makeup of a population through time, which can be driven by various factors including natural selection, genetic drift, and migration. It is not limited to the study of biology and can also be observed in other fields such as geology and anthropology. Evolution does not always result in improvements or progress towards a certain goal, as some adaptations may be more advantageous in certain environments but not in others.

Question 18

A group of differentiated cells that work together to carry out a similar function is known as a(n)

Accepted Answer

A group of differentiated cells that work together to carry out a similar function is known as a tissue. This is the basic unit of organization in multicellular organisms.

B) Organ system is made up of different organs that work together to perform a specific function. 
C) Unicellular organism is a single-celled organism. 
D) Protein is a biomolecule made up of amino acids. 
E) Gene is a unit of heredity that is transferred from a parent to their offspring and determines some characteristic of the offspring.

Question 19

In terms of increasing complexity, the order of parts of a multicellular animal is

Accepted Answer

This is the correct order of increasing complexity in a multicellular organism, starting from the smallest unit of molecules, to cells, then tissues, organs, and finally organ systems.

Question 20

Which is evidence that an organ system provides a level of function not possible with individual organs operating independently?

Accepted Answer

Blood circulation is a function of the cardiovascular system, which involves the heart, blood vessels, and blood. This system provides the essential function of oxygen and nutrient delivery to different organs and tissues of the body. It is not possible for individual organs to function independently and provide oxygen and nutrient delivery to all body tissues without the cardiovascular system's collective function.

Answer: C
 The immune system is a network of organs, tissues, and cells that work together to protect the body from invading pathogens, such as viruses and bacteria. The production of antibodies by B-cells is a crucial process in the immune system's defense against these pathogens. This process cannot take place with individual organs acting independently.

Option A is incorrect as thick fur on bear's body is not a function of an organ system.

Option D is incorrect as the fact that bones are made up of living cells does prove the point that organ systems provide a level of function not possible in individual organs operating independently.

Option E is incorrect as the production of digestive enzymes by the dog's stomach does not involve the collective function of organ systems.

Quiz 1: Studying Life