Biology (DOST JLSS Reviewer)

This Biology Practice Test is comprised of 50 random questions from General Biology. It is comprised of questions from topics such as Cell/Cell Cycle/Cell Transport System; Energy Transformation; Organismal Biology; Genetics; and Evolution. Please read the questions carefully and choose the correct answer from the choices below. The correct answer will be marked green; otherwise, it will be marked red. Good luck!

The following table indicates the presence or absence of selected traits for a set of animal species. The data about which trait provides the strongest evidence that all of the animal species in the table share a common ancestor?

rotating shoulder

four limbs

epidermal scales

mammary glands

A pigeon zygote contains 80 chromosomes. How many chromosomes did the zygote receive from its mother?

Which of the following molecules crosses through a semipermeable membrane during the process of osmosis?

Glucose

Water

Sodium

Proteins

Which of the following statements is true regarding the energy source used in primary vs. secondary active transport?

Primary active transport uses chemical energy such as ATP, while secondary active transport uses an electrochemical gradient.

Both primary and secondary active transport use chemical energy like ATP.

Both primary and secondary active transport use an electrochemical gradient.

Primary active transport uses an electrochemical gradient, while secondary active transport uses chemical energy such as ATP.

The living material comprising the bulk of a cell is called the:

Protoplasm

Chloroplast

Genes

Cytochrome

A genetic mutation causes a snake to have brown skin. After many generations, most of the snake population has the brown skin mutation. Which of the following most likely caused this change?

Snakes with the brown skin mutation are able to survive and reproduce more successfully than snakes without it.

The same mutation occurred in other snakes in response to environmental conditions.

All the snakes in the area were infected with the mutation.

The other snakes changed their colors to mimic the brown snake.

Pepstatin binds to the enzyme pepsin. The substrate is still able to bind to the active site, but the reaction is blocked. What is this an example of?

Allosteric activation

Competitive inhibition

Noncompetitive inhibition

Compartmentalization

During the cell-mediated immune response, killer T-cells target and kill infected cells. This process is shown in the image below. During an experiment, researchers introduced a substance that caused the Class I MHC molecule to break down. Which of the following best describes how the cell-mediated immune response will be affected?

The killer T-cell will still bind to the infected cell, but the infected cell will instead be killed by a helper T-cell.

The killer T-cell will no longer bind to the infected cell, and as a result, the infected cell will not be killed.

The killer T-cell will still bind to the infected cell, but the infected cell will not be killed.

The killer T-cell will no longer bind to the infected cell, and the infected cell will instead be killed by killer T-cells releasing long-distance signals.

Tahira placed a collection of red blood cells into a container filled with an unknown solution. Once in the container, Tahira noticed that the red blood cells swelled and some of them burst. What type of solution were the red blood cells placed in?

An isotonic solution

A hypertonic solution

A hypotonic solution

Which answer choice best describes the hind leg bones seen in the modern-day whale?

Analogous structures to the fins of living sharks

Fossils from extinct predecessors

Homologous structures to the bird wings

Vestigial structures that were formerly functional

The following is an excerpt from a scientific paper written by Levy et al.

The plant cell wall is a barrier to virus exit from and entry into cells. Thus, successful infection requires that plant viruses encode movement proteins to transport the viral genome locally cell-to-cell within a leaf and on into the vascular system, through which the virus will systematically invade the plant.

Which of the following best predicts how movement proteins help plant viruses travel from one plant cell to another?

Movement proteins increase the movement of vacuoles between plant cells.

Movement proteins increase the surface area of plasma membranes between plant cells.

Movement proteins increase the permeability of the plasmodesmata between plant cells.

Movement proteins increase the movement of transport vesicles between plant cells.

Which of the following are roles of amino acids at an enzyme's active site?

Converting the enzyme to receive a different substrate

Binding the substrate to the enzyme

Changing the enzyme itself

Preventing the substrate from entering the chemical reaction

What is true of a competitive inhibitor?

It has a structure similar to the substrate.

It has the same mass as the substrate.

It forms the same products as the substrate.

It binds with the enzyme in a place other than the active site.

A group of students are studying flower color inheritance in the garden pea plant (Pisum sativum). They obtain a purple-flowered pea plant of unknown ancestry, allow it to self-pollinate, and collect 60 6060 of its seeds. After planting the seeds, they observe the growth of 42 4242 purple-flowered plants and 18 1818 white-flowered plants.

Which of the following best explains the flower colors seen in the offspring?

Purple flowers and white flowers are codominant.

White flower color is a trait recessive to purple flower color.

A somatic mutation in the flower color gene produced the white flower color.

The flower color changes as the plants mature.

What is meant by the term "genetic variation?"

Some individuals have different genes than others

Some individuals have the same genes as others

Some genes are multiplied in tetraploid organisms

Some chromosomes are longer than others

During cell communication in the nervous system, chemical messengers called neurotransmitters travel between neurons. As they travel, neurotransmitters send messages from one neuron to another. Which of the following best describes the role of neurotransmitters in neuron-to-neuron communication?

Neurotransmitters are local regulators that allow neurons to communicate over long distances.

Neurotransmitters are local regulators that allow neurons to communicate over short distances.

Neurotransmitters are long-distance signaling molecules that allow neurons to communicate over short distances.

Neurotransmitters are long-distance signaling molecules that allow neurons to communicate over long distances.

The flower of a plant is involved in reproduction. Which parts are male and which are female?

Male: ovary; female: stamen

Male: style; female: filament

Male: stamen; female: pistil

Male: xylem; female: anther

Which of the following is true regarding the proteins involved in facilitated diffusion?

Ions such as sodium, potassium, and calcium can move across the membrane through the use of channel proteins.

Channel and carrier proteins transport materials at different rates.

Channel and carrier proteins allow molecules to diffuse passively against their concentration gradients.

Aquaporins are a type of carrier protein.

Fill in the blanks: Proteins are made of different ____________ which are arranged in different orders, or _________________.

ribosomes, tRNAs

mRNA, bases

polymers, monomers

amino acids, sequences

A scientist hydrolyzes ATP in a laboratory test tube. He finds that about 3 times as much heat is released than when the same amount of ATP is hydrolyzed in a cell. What best explains the scientist's observation?

Cells are less efficient at producing heat.

Enzymes in cells use heat energy to catalyze reactions.

Cells often convert some of the energy from ATP hydrolysis into other usable forms.

ATP hydrolysis in a cell makes different products than in a test tube.

Ptyalin is an enzyme produced in the:

Pancreas

Salivary glands

Thyroid glands

Pituitary glands

Which of the following describes the function of the sodium-potassium pump?

The sodium-potassium pump process begins when potassium attaches to the pump, which hydrolyzes ATP.

Sodium and potassium ions bind to the pump at the same time, and then sodium is released.

Potassium cannot attach to the pump until the sodium ions detach from the pump.

After ATP hydrolysis occurs, the phosphate group attaches to the pump before the sodium ions.

Which correctly places the stages of mitosis in order?

metaphase, prophase, interphase, telophase

prophase, metaphase, anaphase, telophase

metaphase, prophase, interphase, telophase

prophase, metaphase, anaphase, cytokinesis

How does an enzyme affect the rate of a reaction?

It raises the activation energy of the reaction, decreasing the reaction rate.

It lowers the activation energy of the reaction, decreasing the reaction rate.

It raises the activation energy of the reaction, increasing the reaction rate.

It lowers the activation energy of the reaction, increasing the reaction rate.

Which of the following is an example of active transport?

Oxygen exchanging between red blood cells and liver cells

Water moving out of the small intestine

Sodium being reabsorbed in the kidney

Carbon dioxide exchanging between muscle cells and red blood cells

Which statement is true of enzymes?

Changes in temperature do not affect enzymes.

The activity of an enzyme might change as pH changes.

Enzymes are non-specific.

Enzymes work independent of substrate concentration.

Which of the following correctly describes meiosis?

Meiosis begins with a diploid parent cell and ends with two diploid daughter cells.

Meiosis begins with a haploid parent cell and ends with four haploid daughter cells.

Meiosis begins with a diploid parent cell and ends with four haploid daughter cells.

Meiosis begins with a haploid parent cell and ends with two haploid daughter cells.

A gray wolf's sperm contains 39 chromosomes. He mates with a female gray wolf. How many chromosomes will there be in the resulting zygote?

156

19.5

The data above represent the results of three different crosses in which a single gene determines whether a certain organism is blue or yellow.

Which of the following best describes how this gene is inherited from parents to offspring?

The allele for yellow is an autosomal dominant allele because no blue offspring are produced in cross 1.

The allele for blue is an autosomal recessive allele because no blue offspring are produced in cross 1.

Color is an inherited as an incompletely dominant trait because a 1:1 phenotypic ratio of blue-to-yellow is observed in cross 3.

The allele for yellow is an autosomal recessive allele because a 3 : 1 phenotypic ratio of blue-to-yellow is observed in cross 2.

The existence of microorganisms in the human gastric system is an example of:

Meiosis

Parasitism

Phylesis

Mutualism

The U shaped pipe shown in the figure below is divided with a membrane that is only permeable to water. Which of the following best describes how water will flow through the membrane?

The water levels are already equal so water will not flow through the semipermeable membrane.

Water will flow from side A into side B.

Water will flow from side B into side A.

What level does the mice primarily eat in?

3rd trophic level

1st trophic level

2nd trophic level

4th trophic level

A scientist views a unicellular organism called a euglena under a microscope. Based on the diagram, what type of organism is the euglena and why?

The euglena is eukaryotic, because it has a flagellum.

The euglena is prokaryotic, because it has a chloroplast.

The euglena is eukaryotic, because it has a nucleus.

The euglena is prokaryotic, because it has mitochondria.

How is ATP hydrolysis used to power other cellular reactions?

It acts as an enzymatic catalyst.

It produces water which is used to fuel other reactions.

It adds a phosphate to ADP.

It is coupled with endergonic reactions.

What organelle is the site of photosynthesis in plants?

Chloroplasts

Ribosomes

Cytoplasm

Mitochondria

The Calvin cycle is considered light-independent because it can occur in darkness. However, most often the Calvin cycle takes place in sunlight. Which of the following likely explains why?

RuBP regeneration requires sunlight in order to occur and continue the Calvin cycle.

The enzymes involved in the Calvin cycle are unable to bind substrates in the dark.

Sunlight is important in activating carbon fixation in the Calvin cycle.

The Calvin cycle requires ATP and NADPH, which require sunlight to be produced.

The enzyme ptyalin helps digest carbohydrates, while the enzyme pepsin helps digest proteins. What prevents ptyalin and pepsin from digesting the same type of food?

One is a protein and the other is a carbohydrate.

They have different shapes.

They require a different number of molecules to react.

They have the same amino acids chain.

Which of the following is true regarding the cell theory?

All living organisms are made of one or more cells.

Cells can be formed from living or non-living things.

Cells are non-living entities.

Cells are the basic units of life.

Emma believes viruses are not living organisms while Kayla believes viruses are living organisms. Who is correct and why?

Emma, because viruses cannot reproduce on their own.

Kayla, because viruses grow and replicate

Kayla, because viruses are considered a type of living cell

Emma, because viruses contain nucleic acid and proteins

Which of the following is true regarding receptor-mediated endocytosis (RME)?

RME is used to transport materials into the cell using pores in the cell membrane.

RME is used to transport material out of the cell.

RME is non-specific.

RME involves the use of coat proteins such as clathrin.

Which of the following best explains how an individual's evolutionary fitness is measured?

By its fighting abilities

By its hunting strategies

By the ease of its survival

By its ability to reproduce

Which of the following correctly describes how mitosis and meiosis are different?

DNA replication occurs prior to mitosis but not meiosis.

Sister chromatids separate during meiosis but not mitosis.

The number of chromosomes is doubled after mitosis, while the number of chromosomes remains the same after meiosis.

Mitosis produces genetically identical daughter cells, while meiosis produces genetically unique daughter cells.

The graph below shows a metabolic pathway. Which of the following does the graph most likely represent?

An endergonic reaction

A dehydration synthesis reaction

A catabolic pathway

An anabolic pathway

The human body has 23 homologous pairs of chromosomes. How many chromosomes does a somatic cell have?

What type of microscope would be most effective for studying a living cell?

Transmission electron microscope

Scanning electron microscope

Magnifying glass

Light microscope

Which of the following statements is true regarding anabolism?

In anabolism, larger molecules are made from smaller molecules.

Energy is released during anabolic reactions.

Anabolism is the sum of all the chemical reactions in a cell.

Anabolism uses the process of hydrolysis to join molecules together.

What is the main function of cytoplasm in a cell?

Regulating the transport of molecules into and out of the cell

Synthesizing proteins in the cell

Packaging and sending out proteins and lipids

Suspending cellular structures and providing a place for cellular functions to take place

Which of the following molecules is used as "energy currency" for the cell?

Phosphate group

Water

ATP

ADP

In animals, sexual reproduction depends on the production of gametes. Which of the following processes produces gametes in animals?

Meiosis

Binary fission

Mitosis

Fragmentation

Photosynthesis can be divided into two steps: the light-dependent reactions and the Calvin cycle. Which of the following is true regarding these two steps?

The light-dependent reactions use ATP from the Calvin cycle, and the Calvin cycle uses energy from absorbed sunlight.

During the light-dependent reactions, carbon dioxide is fixed to produce sugars that form glucose.

The Calvin cycle converts water molecules into oxygen gas as a byproduct of its reactions.

The light-dependent reactions take place in the thylakoid membrane, and the Calvin cycle takes place in the stroma.