bio
Which sequence lists the cell images in chronological order for mitosis?
4, 2, 3, 1
A scientist observes that, when the pH of the environment surrounding an enzyme is changed, the rate the enzyme catalyzes a reaction greatly decreases. Which statement best describes how a change in pH can affect an enzyme?
A pH change can cause the enzyme to change its shape.
Which statement best compares a protein and a carbohydrate?
A protein has a unique structure to assist chemical reactions, and a carbohydrate stores energy.
A protein in a cell membrane changed its shape to move sodium and potassium ions against their concentration gradients. Which molecule was most likely used by the protein as an energy source?
ATP
Which mutation would most likely affect the organism's phenotype?
AUG-GCU-UGA
Which statement correctly describes how a protein is formed?
Amino acids are bonded together in a long chain to form a new molecule
Which statement best describes the relationship between an allele and a gene?
An allele is a variation of a gene that can be expressed as a phenotype.
Which statement describes a cell process that is common to both eukaryotic and prokaryotic cells?
Both cell types use ribosomes to carry out translation.
Photosynthesis and cellular respiration are two major processes of carbon cycling in living organisms. Which statement correctly describes one similarity between photosynthesis and cellular respiration?
Both include reactions that transform energy.
Which statement is true for all prokaryotic and eukaryotic organisms?
Both types of organisms assemble proteins through transcription and translation.
Carbon can combine with many different elements but frequently combines with oxygen, hydrogen, and nitrogen to form organic molecules. Which statement best explains why carbon is able to form a large number of different molecules?
Carbon can form four covalent bonds
Which statement best describes the outcomes of both meiosis and mitosis?
Cell division results in daughter cells that contain DNA.
Before cellular division, the cell must duplicate its DNA so that daughter cells will contain complete copies of the DNA.
DNA is made of two strands of complementary nucleotides.
Which statement best describes how organisms use DNA and amino acids to synthesize a protein?
DNA is transcribed into mRNA, which is translated by the ribosome to produce an amino acid chain.
Which statement best describes how parents influence this trait?
Each parent contributes one allele for this trait.
A group of students measured a ten-square-meter section of a pond ecosystem and recorded observations. Which statement is a testable hypothesis?
If the frogs are startled, then they will jump into the water.
The endoplasmic reticulum is a network of membranes within the cell, and it is often classified as rough or smooth, depending on whether there are ribosomes on its surface. Which statement best describes the role of rough endoplasmic reticulum in the cell?
It aids in the production of membrane and secretory proteins.
Which statement correctly describes how carbon's ability to form four bonds makes it uniquely suited to form macromolecules?
It forms large, complex, diverse molecules.
The rough endoplasmic reticulum and Golgi apparatus work together in eukaryotic cells. What is one way that the rough endoplasmic reticulum assists the Golgi apparatus?
It packages new protein molecules into vesicles.
Substance A is converted to substance B in a metabolic reaction. Which statement best describes the role of an enzyme during this reaction?
It speeds up the reaction without being consumed.
A genetic mutation did not result in a change in the sequence of amino acids of a protein, and the function of the protein was not changed. Which statement best describes the genetic mutation?
It was a silent mutation that caused a change in the DNA of the organism.
A mutation occurred that caused a change in an mRNA sequence. The mRNA codon UAC was replaced by the codon UAA. Which statement describes the most likely outcome of the mutation?
It will result in an incomplete protein that does not function properly.
Mitosis and meiosis are processes by which animal and plant cells divide. Which statement best describes a difference between mitosis and meiosis?
Mitosis produces genetically identical daughter cells.
Mitosis and meiosis are processes by which animal and plant cells divide. Which statement best describes a difference between mitosis and meiosis?
Mitosis produces genetically identical daughter cells.
Which statement describes one difference between mitosis and meiosis in animal cells?
Mitosis produces two daughter cells, and meiosis produces four daughter cells.
A farmer observed that an increase in a field's soil nitrogen content was followed by an increase in producer productivity. What does this observation most likely indicate about the relationship between nitrogen and the producers in the fi eld?
Nitrogen was a limiting factor.
Which statement correctly describes how nitrogen in the atmopshere is converted into usable nitrogen for living things in the soil?
Nitrogen-fixing bacteria in plant roots convert nitrogen gas into ammonium.
Which statement best describes the process by which the millions of body cells that form a housefly can all contain the same genetic information?
Original DNA is duplicated during replication and then distributed into two new cells.
A sodium-potassium pump within a cell membrane requires energy to move sodium and potassium ions into or out of a cell. The movement of glucose into or out of a cell does not require energy. Which statement best describes the movement of these materials across a cell membrane? Selected:
Sodium and potassium ions move by active transport, and glucose moves by facilitated diffusion.
Which characteristic is shared by all organisms?
The ability to reproduce
Which statement best describes the phase of the cell cycle shown?
The cell is in telophase of mitosis because the cell is separating and each new cell contains two copies of each chromosome
Which event most likely occurs next in mitosis?
The cell membrane pinches inward to divide the cytoplasm.
A scientist tries to growth the microbes in her lab but is unable to keep a constant 200 degrees F in the incubation chamber and the microbes died. What is the most likely reason for this difficulty?
The enzymes in the microbe could not function outside of their optimum temperature because they changed shape.
An inversion occurs along part of a chromosome. How does the inversion most likely affect the region in which it occurs?
The information in the region is read differently during transcription.
Which statement best describes a difference between prokaryotic cells and eukaryotic cells?
The presence of membrane-bound organelles in eukaryotic cells indicates that they are more complex than prokaryotic cells.
Alveoli are microscopic air sacs in the lungs of mammals. Which statement best describes how the structure of the alveoli allows the lungs to function properly?
They increase the surface area of the lungs, allowing efficient gas exchange.
Which statement describes the genetic material scientists are most likely studying?
They study chromosomes that contain genes, which are DNA segments.
Which statement best describes an effect of the low density of frozen water in a lake?
When water in a lake freezes, it floats, providing insulation for organisms below.
In a flowering plant species, red flower color is dominant over white flower color. What is the best description of the genotype of any red-flowering plant resulting from this species?
a red allele present on at least one of two homologous chromosomes
Carbohydrates and proteins are two types of macromolecules. Which functional characteristic of proteins distinguishes them from carbohydrates?
ability to catalyze biochemical reactions
Which effect is most likely caused by nondisjunction during meiosis?
an extra chromosome
A mutation occurs in the genes that code for coat color in deer. Which change will most likely result from this mutation?
an increase in coat-color diversity in the population
At a point in the cell cycle, chromosomes have aligned near the middle of a cell. Which sequence of events will the cell need to complete to produce two identical daughter cells?
anaphase → telophase → cytokinesis
Which part of the apple flower produces cells by meiosis?
anther
Acetylcholinesterase is an enzyme that breaks down the neurotransmitter acetylcholine into acetic acid and choline in nerves and muscles so that muscles can relax after being stimulated. How does Acetylcholinesterase affect the degradation of acetylcholine into acetic acid and choline molecules?
by decreasing the amount of energy needed to complete the reaction
A scientist formed Chemical X in a laboratory. The material was then analyzed by other scientists. Analysis showed that the chemical was composed of repeating sugar molecules. Which type of organic molecule was most likely formed by the scientist in the laboratory?
carbohydrate
Life functions are performed at many levels of biological organization. Which level of biological organization is the simplest level at which a structure can support life functions?
cell
Carbon dioxide and oxygen are molecules that can move freely across a plasma membrane. What determines the direction that carbon dioxide and oxygen molecules move?
concentration gradient across the plasma membrane
Which characteristic is shared by both prokaryotes and eukaryotes? a. need oxygen gas to breathe
contain genetic material
The diagram shows a reaction that forms a polymer from two monomers. What is this type of reaction called?
dehydration synthesis
A mutation occurs at the midpoint of a gene, altering all amino acids encoded after the point of mutation. Which mutation could have produced this change?
deletion of two nucleotides
Which example is an activity that a fish most likely uses to maintain homeostasis within its body?
exchanging gases through its gills to regulate oxygen levels
A genetic mutation involving a single base causes an error that affects the sequence of the next 500 amino acids in a protein. Which type of mutation could have produced this type of error in the protein?
frame-shift
Which sequence correctly describes the flow of energy between organisms in the marine food web?
from small fish to penguins to seals
Lungs and capillaries both have porous linings that allow certain substances to move into or out of the structures. Which function do these porous linings most likely serve in living organisms?
gas exchange
The diagram below represents events that occur during sexual reproduction. The stages labeled A, B, and C are necessary to ensure that the offspring will inherit...
half of their chromosomes from each parent
Using a microscope, a student observes a small, green organelle in a plant cell. Which energy transformation most likely occurs first within the observed organelle?
light to chemical
Which structure and function are common to all eukaryotic organisms and distinguishes them from prokaryotic organisms?
mitochondria that perform cellular respiration
The graphs illustrate change in a lizard population over time. Which process most likely led to the change in the lizard population?
natural selection acting on a beneficial trait
Which process helps to preserve the genetic information stored in DNA during DNA replication?
nucleotides lining up along the template strand according to base pairing rules
Which activity would a cell be unable to perform if a mutation occurred that caused the Golgi apparatus to stop functioning?
packaging proteins for transport out of the cell
Blood type is inherited though multiple alleles, including IA, IB, and i. A child has type A blood. If the father has type AB blood, what are all the possible phenotypes of the mother?
phenotypes O, A, B, AB
A species of snapping turtles has a tongue that resembles a worm. The tongue is used to attract small fish. Which best describes the interaction between the fish and the snapping turtle?
predation
A student looking through a microscope records observations about a cell. Which stage of the cell cycle has the student described?
prophase
in North America, the eastern spotted skunk mates in late winter, and the western spotted skunk mates in late summer. Even though their geographic ranges overlap, the species do not mate with each other. What most likely prevents these two species from interbreeding?
reproductive isolation
Which characteristic for eye color would be the same for both individuals?
the location of the gene
The bacterium Acetobacter aceti is found in acidic environments and has an acidic cytoplasm. For this reason, most of its proteins are able to function in acidic conditions. This property distinguishes Acetobacter aceti proteins from those of most other organisms.
the process used to form proteins by transcription and translation
What must be transmitted to new DNA strands during replication to maintain genetic information?
the sequence of bases from existing DNA strands
Genetic engineering has led to genetically modified plants that resist insect pests and bacterial and fungal infections. Which outcome would most likely be a reason why some scientists recommend caution in planting genetically modified plants?
unplanned ecosystem interactions