Blood oxygen levels are most likely low when blood _____.
A. leaves the aorta
B. fills the right atrium
C. reaches body tissues
D. flows through arteries
Blood continually flows in one direction, beginning in the heart and proceeding to the arteries, arterioles, and capillaries. When blood reaches the capillaries, exchanges occur between blood and tissues. After this exchange happens, blood is collected into venules, which feed into veins and eventually flow back to the heart’s atrium. The heart must relax between two heartbeats for blood circulation to begin.
Two types of circulatory processes occur in the body:
Systemic circulation
- The pulmonary vein pushes oxygenated blood into the left atrium.
- As the atrium relaxes, oxygenated blood drains into the left ventricle through the mitral valve. 3. The left ventricle pumps oxygenated blood to the aorta.
- Blood travels through the arteries and arterioles before reaching the capillaries that surround the tissues.
Pulmonary circulation
- Two major veins, the Superior Vena Cava and the Inferior Vena Cava, brings deoxygenated blood from the upper and lower half of the body.
- Deoxygenated blood is pooled into the right atrium and then sent into the right ventricle through the tricuspid valve, which prevents blood from flowing backward.
- The right ventricle contracts, causing the blood to be pushed through the pulmonary valve into the pulmonary artery.
- Deoxygenated blood becomes oxygenated in the lungs.
- Oxygenated blood returns from the lungs to the left atrium through the pulmonary veins.
Therefore, the Correct Answer is B.
More Questions on TEAS 7 Science
-
Q #1: Which is true regarding the Urinary system?
A. Kidneys makes urine, Kidney help regulate water balance.
B. As a person ages, kidney tissue and filtration capacity increase, Regulates levels of electrolytes such as sodium and potassium.
C. Eliminates metabolic wastes., Kidneys makes urine., Kidney help regulate water balance.
D. Kidney help regulate water balance, Regulates levels of electrolytes such as sodium and potassium, Eliminates metabolic wastes
Answer Explanation
Kidneys makes urine is incorrect. Kidneys do not make urine. They help regulate water balance, regulate levels of electrolytes such as sodium and potassium, and eliminate metabolic wastes. Urine is a byproduct of these functions.
As a person ages, kidney tissue and filtration capacity increase is incorrect. As a person ages, the kidneys and bladder change. This can affect functions such as bladder control and how well the kidneys filter blood. Kidney changes range from a decrease in kidney tissue to decreased filtration capacity.
Kidneys help regulate water balance is correct. Kidneys help regulate water balance, regulate levels of electrolytes such as sodium and potassium, and eliminate metabolic wastes. Urine is a byproduct of these functions.
Regulates levels of electrolytes such as sodium and potassium is correct. There must be a continual balance of water and salt in the blood. The urinary system, specifically the kidneys, help maintain this balance. It also balances levels of metabolites or electrolytes such as sodium, potassium, and calcium.
Eliminates metabolic wastes is correct. Urea, creatinine, uric acid, and ammonium are the primary types of nitrogenous wastes excreted from the body. The urinary system also detects and excretes excess water from the blood and out of the body.
-
Q #2: Which of the following determines the strength of an acidic solution?
A. Litmus paper that turns red
B. Litmus paper that turns blue
C. Measured pH value equal to 7
D. Measured pH value less than 7
Answer Explanation
Both litmus paper and a pH scale can be used to indicate whether a solution is acidic. However, a pH scale can also determine the strength of an acid.
Researchers can determine the strength of an acid or a base by measuring the pH of a solution. The pH value describes how acidic or basic a solution is. On pH scale, shown below, if the number is less than 7 the solution is acidic. A pH greater than 7 means the solution is basic. When the pH is exactly 7, the solution is neutral.
-
Q #3: The sequence of amino acids in a gene determines
A. the primary structure of a codon
B. the primary structure of a protein
C. the primary structure of a nucleotide
D. the primary structure of a nucleic acid.
Answer Explanation
The sequence of amino acids in a gene determines the primary structure of a protein. The components necessary for translation are located in the cytoplasm. Translation is the making of proteins by mRNA binding to a ribosome with the start codon that initiates the production of amino acids. A peptide bond forms and connects the amino acids together. The sequence of amino acids determines the protein’s structure, which determines its function.
-
Q #4: An atom has 28 protons, 32 neutrons, and 28 electrons. What is the name of this isotope?
A. Nickel-32
B. Nickel-60
C. Germanium-56
D. Germanium-60
Answer Explanation
The number of protons, 28, gives the atomic number, which identifies this atom as nickel. The mass is the number after the dash in the isotope name, which is determined by adding the numbers of protons and neutrons (28 + 32 = 60).
-
Q #5: As soon as an invader, known as a(n) _____, enters the body, the body begins to fight.
A. antibody
B. pathogen
C. trigger
D. vaccination
Answer Explanation
Pathogen is an infectious foreign body that enters the body and causes disease or illness to the person. There are five types of pathogens: viruses, bacteria, fungi, protozoa, and worms. Pathogens have antigen proteins found on their surface and are unique to each pathogen.
Antibody is a protein produced by the body’s immune system when it detects harmful substances (antigens). There are many different antibodies found in the body. Each one is unique and protects the body against the specific antigen that it detects at any given time. If there are no antibodies for a specific antigen, the more likely you are to develop an illness.
Vaccinations are the introduction of a dead or disabled pathogen or of a harmless microbe with the protein of a pathogen on its surface into the body. Often administered through needle injection, to stimulate the immune system to produce immunity to a specific disease Immunity protects the body from a disease when exposed to it.
There are four types of immunity: natural/passive, natural/active, artificial/passive, and artificial/ active.
- Natural/passive – Babies receive immunities from breastmilk.
- Natural/active – The body produces antibodies to combat an illness when a person becomes sick.
- Artificial/passive – This immunity is temporary and requires doses of serum to maintain the immunity.
- Artificial/active – A vaccination provides artificial/active immunity.
-
Q #6: The diffusion of nutrients through the walls of the digestive system is critical to homeostasis in the body. Where does the majority of this diffusion take place in the digestive system?
A. Stomach
B. Esophagus
C. Oral cavity
D. Small intestine
Answer Explanation
The duodenum is the first part of the small intestines, located between the stomach and the middle part of the small intestines (jejunum). Once food has mixed with acid in the stomach, it moves into the duodenum, where it then mixes with bile from the gallbladder and digestive juices secreted from the pancreas. In the duodenum, absorption of vitamins, minerals, and nutrients begins.
-
Q #7: Mendel discovered the pattern associated with _____after developing a series of rules in genetics.
A. epigenetics
B. heredity
C. heterogeneity
D. taxonomy
Answer Explanation
Mendel was accurately able to predict the patterns of heredity by studying rules related to genetics. These rules helped shape his theory of heredity. Heredity is the characteristics offspring inherit from their parents.
From experiments with garden peas, Mendel developed a simple set of rules that accurately predicted patterns of heredity. He discovered that plants either self-pollinate or cross-pollinate, when the pollen from one plant fertilizes the pistil of another plant. He also discovered that traits are either dominant or recessive. Dominant traits are expressed, and recessive traits are hidden.
Mendel’s Theory of Heredity
To explain his results, Mendel proposed a theory that has become the foundation of the science of genetics. The theory has five elements:
- Parents do not transmit traits directly to their offspring. Rather, they pass on units of information called genes.
- For each trait, an individual has two factors: one from each parent. If the two factors have the same information, the individual is homozygous for that trait. If the two factors are different, the individual is heterozygous for that trait. Each copy of a factor, or gene, is called an allele.
- The alleles determine the physical appearance, or phenotype. The set of alleles an individual has is its genotype.
- An individual receives one allele from each parent.
- The presence of an allele does not guarantee that the trait will be expressed.
-
Q #8: Fertilization (the fusing of one sperm and an ovum) results in a(n) _____.
A. embryo
B. fetus
C. infant
D. zygote
Answer Explanation
Human intercourse consists of the male introducing sperm into the female’s reproductive system. Sperm may then pass through the female’s reproductive system to the Fallopian tubes where one sperm fertilizes an ovum, creating a zygote. The zygote passes out of the Fallopian tube and implants into the uterine wall to begin gestation. Over nine months, the zygote develops and grows into an embryo and then a fetus. An infant is the baby that is born.
-
Q #9: A student notices a pattern of stripes on five tigers. Each of the five tigers has the same stripe pattern. Using his inductive reasoning, what does he logically assume based on this information?
A. The pattern continues to change over time.
B. Natural adaptations cause this pattern to occur
C. Each offspring will have the same stripe pattern
D. Ancestors of the tigers have different stripe patterns
Answer Explanation
Inductive reasoning involves making specific observations and using them to make broad statements. The student observes that all of the tigers have the same stripe pattern. He can use this observation to make the broad statement that all the tigers’ offspring will have the same stripe pattern.
Inductive reasoning involves drawing a general conclusion from specific observations. This form of reasoning is referred to as the “from the bottom up” approach. Information gathered from specific observations can be used to make a general conclusion about the topic under investigation. In other words, conclusions are based on observed patterns in data.
-
Q #10: Where is skeletal muscle found?
A. Inside the heart
B. Attached to bone
C. Lining the walls of the bladder
D. Within the gastrointestinal tract
Answer Explanation
Skeletal muscle: This muscle cell is striated, long, and cylindrical. There are many nuclei in a skeletal muscle cell. Attached to bones in the body, skeletal muscle contracts voluntarily, meaning that it is under conscious control.
Smooth muscle: This muscle consists of nonstriated muscle cells that are spindle-shaped. Like cardiac muscle cells, smooth muscle cells contain one nucleus. This muscle type is found in the walls of internal organs like the bladder and stomach. Smooth muscle contraction is involuntary and controlled by the autonomic nervous system.
Cardiac muscle: This muscle consists of muscle cells that are striated, short, and branched. These cells contain one nucleus, are branched, and are rectangular. Cardiac muscle contraction is an involuntary process, which is why it is under the control of the autonomic nervous system. This muscle is found in the walls of the heart.
