WGU Introduction to Biology
Which characteristic describes both meiosis and mitosis?
Sister chromatids separate
A biological polymer consists of 358 amino acids linked together covalently.What is this polymer?
A protein
What is the charge of a proton?
+1 (positive)
Consider the results of a dihybrid cross, where Y refers to black fur, y refers to white fur, S refers to short fur, and s refers to long fur. Capitalized letters refer to dominant traits, and lowercase letters refer to recessive traits. The following are the results: YYSS, YYSs, YySS, YySs, YYSs, YYss, YySs, Yyss, YySS, YySs, yySS, yySs, YySs, Yyss, yySs, yyss How many offspring have white fur?
4
A fly is heterozygous for wing length, carrying one allele for the dominant long-winged appearance and one allele for the recessive short-winged appearance.Which percentage of the fly's gametes will carry the short-winged allele?
50%
Which of these is an output of the light-dependent reaction of photosynthesis?
ATP
Some cells need to maintain a set concentration of Na + and K + ions. These cells are able to do this with the help of the Na/K pump, which transports these ions from areas of low concentration to areas of high concentration (against their concentration gradient). Na + is pumped out, and K + is pumped in.Which type of membrane transport is involved in this action?
Active transport
Which situation describes covalent bonding?
An atom shares an electron with another atom.
A subatomic particle has a negative charge and is found in a shell of the atom.What is this particle?
An electron
A cutting is taken from a mature hydrangea plant with blue flowers. The cutting is planted in acidic soil and produces red flowers.What caused the flower color in this hydrangea cutting to change?
An interaction between the genes and the soil
Sister chromatids are being separated and moving towards opposite poles of the cell. Which stage of mitosis is this?
Anaphase
Which of the following statements about macromolecules are true?
Carbohydrates provide structural support to cell walls. ipids speed up chemical reactions.
Which molecule is an input to the Calvin-Benson cycle?
Carbon dioxide
Which of the following has the correct order of biological organization from smallest to largest?
Cell -> Organ System -> Population -> Biome
he two major components of chromosomes are _____ and _____ . *
DNA ; histone proteins
After a rainy day, a leaf has small droplets of water on its surface.Which property of water is this an example of?
Cohesion
Prairie ecosystems are common within continental interiors in the Northern Hemisphere. These ecosystems have a thick, nutrient-rich topsoil and are dominated by grasslands and shrubs.Which activity would have a negative impact on biodiversity in a prairie ecosystem?
Collecting the rich topsoil to sell in surrounding cities
A remora (suckerfish) eating food left over by a shark is an example of which interaction between species?
Commensalism
Biologists estimate that there are 1000 species of bacteria living in the average human stomach. Biologists are studying how these species interact with each other.Which level of ecological organization is being studied?
Community
There are four species of woodpeckers that inhabit the pine forests in the southeastern area of the United States. Individuals of these species utilize many of the same resources for food and nesting.Which level of ecological organization describes the relationship among these four species of woodpecker?
Community
Two species of woodpecker inhabit the same loblolly pine woodland throughout the southeastern United States. Each species requires recently deceased (but still standing) pine trees for reproduction. The woodpeckers excavate their nest cavities in the dead pine trees. In most healthy forests there are generally not enough dead pine trees to provide nests for all the woodpeckers that want to build them.What is the relationship between these two species of woodpecker an example of?
Competition
A cell has divided its chromosomes into two new nuclei. The cytoskeleton of the cell is currently pinching the cell in the middle to form two new cells. In which stage of the cell cycle is this cell?
Cytokinesis
Chromosomes are structures that contain hereditary material that will be passed from one generation to the next.According to this information, which organic molecule must be present in chromosomes?
DNA
Place the steps of DNA replication in the order of occurrence.Select your answers from the pull-down list.
DNA molecule separates into two template strands.2 Two DNA molecules, each with a template strand and a new strand, are formed.4 Complementary nucleotides are added to each template strand.3 DNA molecule unwinds.1
A plastic water bottle is filled with water and placed in the freezer. The next day the frozen water has expanded, causing the plastic bottle to rupture.Which characteristic of water is this an example of?
Density
Which stage of cellular respiration releases the most energy and, therefore, produces the most ATP molecules?
Electron transport chain
In which eukaryotic organelle does protein synthesis occur?
Endoplasmic reticulum
The initial biochemical transformation of glucose during cellular respiration occurs within the cytoplasm of the cell. Glucose is transformed into glucose-6-phosphate as ATP is converted into ADP and a free phosphate group. What is happening to energy in this initial step of glycolysis?
Energy is being released from ATP to power the conversion of glucose.
In the human body, muscle fibers metabolize sugars to produce energy. Fast-twitch muscle fibers, like those used during short-term, vigorous exercise, carry out an anaerobic process that produces less energy per sugar molecule processed.Which metabolic process do fast-twitch muscle fibers carry out?
Fermentation
Which of the following shows the overall reaction for cellular respiration?
Glucose + Oxygen --> Carbon dioxide + Water + ATP
A diploid cell is in G1 phase of the cell cycle. Which of the following would you observe in this cell?
Homologous chromosomes Chromosomes composed of a single chromatid
As winter progresses, ice will form and stay at the surface of a pond as it thickens throughout the season. Which property of water allows this to happen? * 1/1
Hydrogen bonds between water molecules become more stable, and molecules spread out as the temperature decreases causing water to become less dense.
A molecular bond results from an electron being transferred from one atom to another.Which type of bond holds these atoms together?
Ionic
What is true of a eukaryotic cell?
It contains a mitochondrion.
Which of the following could be used to identify an organism as prokaryotic or eukaryotic?
It contains endoplasmic reticulum
Which of the following statements about ATP are true?
It is chemical potential energy. t is generated by phosphorylation of ADP.
What is a characteristic of DNA but not RNA?
It is intertwined with histone proteins
Which of the following statements about fermentation is true?
It occurs in the cytoplasm. It generates less ATP than cellular respiration.
Which stage of cellular respiration releases carbon dioxide as a product?
Krebs cycle
Choose the two substances that are the main components in most eukaryotic cell membranes.
Lipids and proteins
What is the function of the flagellum?
Locomotion and sensing
Which type of cell division results in sex cells?
Meiosis
Which of the following carries the information that determines which amino acids are used to make a protein?
Messenger RNA
Scientists like to know not simply that one variable causes a change in another, but exactly how this occurs, step by step. How does noise damage hair cells? To figure this out, at which levels will scientists probably need to seek answers?
Molecules and organelles
In the harsh arctic tundra, the survival of one species is often dependent on the actions of another. For example, the arctic bumblebee pollinates the arctic poppy flower and receives energy rich nectar in return.Which interaction is occurring between these species?
Mutualism
Which substance is found in ATP?
Nitrogenous base
Fermentation uses sugar in the absence of which molecule?
O 2
A recessive mutation in the DFN3 gene causes deafness. A mother with DFN3 deafness will have sons who all have deafness.How did the sons inherit the gene for deafness?
On the X chromosome from the mother
What is the function of the histones during S phase?
Organizing and helping to unwind the DNA so the replication enzymes can access it
While abroad, a traveler drinks unclean water containing tapeworm cysts. The tapeworm attaches to the intestinal walls of the traveler, absorbing nutrients from the partially digested food. Over the next few months, the traveler experiences ongoing nausea, loss of appetite, and weight loss due to the presence of the tapeworm in his intestines.What is the interaction between the tapeworm and the traveler an example of?
Parasitism
A dog breeder mates two black Labrador retriever dogs. The breeder is surprised by the offspring produced by this crossing. In addition to offspring with beautiful black coats, there are dogs with brown, gray, and tan coats.Which form of inheritance is this an example of?
Polygenic
Which pattern of inheritance is described when a phenotype results from the interaction of many genes?
Polygenic inheritance
Which stage of mitosis is observed in the image? * 0/1
Prophase
Homologous pairs of chromosomes have separated into two cells. Sister chromatids in each cell have not yet lined up in the middle of the cell. Which stage of the cell cycle is this?
Prophase II
If an atom is neutral, which particles are present in equal numbers?
Protons and electrons
Black (B) is the dominant color, and red (b) is the recessive color in a species of beetle. Two beetles that are both Bb are crossed. What percentage of the offspring will be red?
R l r l R Lr L
Which of the following is a difference between RNA and DNA? *
RNA contains uracil, and DNA contains thymine.
What is true regarding the transition from metaphase to anaphase during mitosis?
Sister chromatids are aligned along the center of the cell and then pulled apart into separate chromatids.
Which of the following occurs during anaphase of mitosis?
Sister chromatids are pulled apart at the centromere.
Aquatic habitats (e.g., lakes and streams) throughout the northeastern United States have been damaged by acidic rainfall. Airborne pollutants released by coal-fired power plants acidify the rain that falls in these regions, which has led to wide-scale disruptions to ecosystems and a decrease in diversity in these habitats.Which activity would continue to increase the acidity of the rain and negatively impact biodiversity in these aquatic habitats?
Removing native species
Which of the following statements describing photosynthesis are true?
Solar energy is converted to chemical potential energy. CO2 and glucose are inputs.
A cell undergoing meiosis is currently dividing. The two new daughter cells will be haploid, but the DNA they contain is still replicated. The homologous chromosomes have separated and are ready to start the second division, but they have not yet begun the second round of division. Which stage of the cell cycle is this cell in?
Telophase I
1. _____ is an example of an abiotic factor while _____ is an example of a biotic factor.
Temperature ... bacteria
How is DNA structured during the metaphase stage of mitosis?
The centromere at the center keeps DNA lined up at the cell's equator.
A gene contains the sequence CGCATACGGTAC that results in the amino acid sequence arg-ile-arg-tyr. A mutated version of this gene has an A in place of the second C and produces the amino acid sequence arg-ile-arg-tyr.What is true regarding this mutation?
The mutated gene results in the same amino acid sequence and will result in the same phenotype.
Which of the following statements about hydrogen bonds is true?
They form between an electronegative atom and a hydrogen atom.
A molecule consists of a chain of glucose monomers linked together.What is the function of this molecule within the cell?
To store energy