Question 1

What is the primary function of the large intestine?

Accepted Answer

The primary function of the large intestine is to remove water from undigested waste, helping to form solid stool.

Question 2

Which of the following best describes the result of a mutation in an organism's DNA?

Accepted Answer

Mutations in an organism's DNA can lead to changes in the phenotype, which are the observable characteristics. This can happen because mutations can alter the function of genes, potentially affecting the production of proteins and thus influencing the organism's traits.

Question 3

Starting in 1954, commercial fishers in the northwest Pacific were paid by weight, rather than by the individual fish, for pink salmon. The fishers increased the use of a type of net that selectively catches larger fish. Which of the following effects did this change in fishing techniques most likely have on the salmon population over the next 20 years?

Accepted Answer

The use of nets that selectively catch larger fish would remove those larger fish from the gene pool, leading to a decrease in the average body size of the salmon population over time, as smaller fish would have a higher survival and reproduction rate.

Question 4

A hurricane sweeps across a small Caribbean island, killing 50 percent of the herbivore species on the island. Which of the following is the most immediate result?

Accepted Answer

A reduction in biodiversity is the most immediate result of losing 50 percent of the herbivore species, as it directly decreases the variety of life in that ecosystem.

Question 5

Caytonia is an extinct plant that existed between 200 and 140 million years ago. It had reproductive structures that resemblestructures in modern flowering plants. How do scientists know about the structures of this ancient extinct plant?

Accepted Answer

Scientists study extinct plants like Caytonia by examining their fossilized remains. This allows them to understand the plant's structure, including its reproductive organs, and how it might relate to modern plants. DNA sequencing and genetic engineering are not applicable to extinct plants for which no living tissue exists, and observing modern plants in similar habitats can provide ecological insights but not direct information about the extinct plant's structures.

Question 6

Many land plants store energy in starch. When energy is needed, the starch molecules can be broken down quickly. This chemical reaction produces which of the following?

Accepted Answer

Starch is a polysaccharide made up of glucose units. When it is broken down, it releases glucose, a monosaccharide, which is a type of simple sugar that plants use for energy.

Question 7

Which of the following best describes the formation of a zygote?

Accepted Answer

A zygote is formed through the fusion of a sperm cell nucleus and an egg cell nucleus, combining their genetic material to create a new cell with a complete set of chromosomes.

Question 8

Which of the following functions does active transport perform in a cell?

Accepted Answer

Active transport is a cellular process that moves substances against their concentration gradient, requiring energy in the form of ATP. This is essential for maintaining concentration differences of ions and other substances across cell membranes.

Question 9

European rabbits were introduced to Australia in 1859. The rabbits reproduced rapidly in their new habitat, displaced other animals, and overgrazed vegetation. In an attempt to reduce the rabbit population, a virus was introduced in 1951. This virus is usually deadly to European rabbits.When the virus was first introduced, the rabbits died in large numbers, but the death rate decreased over time. Which of the following best explains the decrease in the rabbit death rate?

Accepted Answer

Natural selection favored rabbits that are resistant to this virus, leading to a decrease in the death rate as these resistant individuals survived and reproduced, passing on their resistance to their offspring.

Question 10

Which of the following is a main function of the cell wall?

Accepted Answer

The main function of the cell wall is to give the cell a rigid structure, which helps protect the cell and maintain its shape.

Question 11

The mold Aspergillus flavus grows on grain. A. flavus produces a toxin that binds to DNA in the bodies of animals that eat the grain. The binding of the toxin to DNA blocks transcription, so it directly interferes with the ability of an animal cell to do which of the following?

Accepted Answer

The toxin produced by Aspergillus flavus interferes with transcription, a process that occurs in the nucleus where DNA is used as a template to make RNA. This RNA then carries the genetic information needed for protein synthesis from the nucleus to the cytoplasm and ribosomes, where proteins are made. Blocking transcription directly affects the cell's ability to send these protein-building instructions.

Question 12

In a mouse population inhabiting a grassland area, a mutation occurs that results in a new coat color allele.Which of the following factors has the greatest effect on whether the new coat color will become more common in the mouse population?

Accepted Answer

The new coat color allele's impact on the survival of mice in their environment is the most significant factor in determining whether it will become more common. If the mutation confers a survival advantage, such as better camouflage or resistance to disease, it is more likely to be passed on to future generations, increasing its frequency in the population.

Question 13

Capillaries are part of which body system?

Accepted Answer

Capillaries are small blood vessels that are part of the circulatory system, where they facilitate the exchange of water, oxygen, carbon dioxide, and many other nutrients and waste substances between blood and the tissues of the body.

Question 14

Similar structures are present in the embryos of fish, chickens, and rabbits. In fish, these structures develop into gills, but in chickens and rabbits, they either disappear or develop into other body parts later in embryonic development.Which of the statements below best explains the presence of these structures in the embryos of all three species?

Accepted Answer

The presence of similar structures in the embryos of fish, chickens, and rabbits suggests a common evolutionary ancestor. These structures may serve different functions or no function in the adult forms, but their presence during embryonic development indicates a shared evolutionary history.

Question 15

Which process do the animals in the food web use to convert energy from food into ATP?

Accepted Answer

Animals convert energy from food into ATP through the process of cellular respiration. This process involves breaking down glucose (or other nutrients) in the presence of oxygen to produce ATP, carbon dioxide, and water.

Question 16

Which organism in the food web is classified into kingdom Fungi?

Accepted Answer

King bolete is classified into kingdom Fungi, as it is a type of mushroom, and all mushrooms belong to the Fungi kingdom.

Question 17

Which of the following organisms is a secondary consumer in this food web?

Accepted Answer

A secondary consumer is an organism that eats primary consumers. The least chipmunk is a secondary consumer because it feeds on primary consumers like insects.

Question 18

Which of the following releases oxygen into this food web ecosystem?

Accepted Answer

Idaho fescue, like other plants, releases oxygen as a byproduct of photosynthesis, a process where carbon dioxide and water are converted into glucose and oxygen using sunlight.

Question 19

In phenylketonuria (PKU), an enzyme that converts one amino acid into another does not work properly. Which of the following is the most likely cause of this genetic condition?

Accepted Answer

A mutation in the DNA sequence that codes for the enzyme is the most likely cause of phenylketonuria (PKU). This genetic condition occurs when there is a mutation in the gene responsible for producing the enzyme phenylalanine hydroxylase, which is necessary for converting the amino acid phenylalanine into tyrosine.

Question 20

The water cycle would not occur if which of the following were missing?

Accepted Answer

Solar energy is essential for the water cycle as it powers the evaporation of water from surfaces, leading to condensation and precipitation. Without solar energy, the cycle would not occur. Animals, bacteria, and ice caps, while part of the broader ecological system, are not essential for the basic process of the water cycle.

Quiz 1: Biology