High blood levels of the amino acid ________ have been linked to increased risks of cardiovascular disease.
A student wants to determine how his classmates feel about school. He does a survey away from school so all participants will be willing to answer freely. In several cases, younger siblings of his classmates are present, so he lets them take the survey too. He surveys a total of 50 students. Has he done a well-designed, controlled experiment?
Answer: No. His independent variable is not controlled.
Explanation:
What genetic describes a change of the sequence of a dna molecule?
DNA stands for deoxyribonucleic acid. It has a double strand that contains the genes (a hereditary material) of the organism. The DNA are composed of a nitrogenous base, phosphate and a sugar (deoxyribose). The bases are adenosine, tyrosine, uracil and guanine. And they are needed to be matched to carry the trait. The nitrogenous base are the traits that contains the genetic material and are mostly composed of nucleic acids. James D Watson and Francis Crick are the first scientist to formulate an accurate description of the DNA’s (deoxyribonucleic acid) complex , double-helical structure. They discovered that base pairing nucleotides must be; adenine and thymine; and cytosine and guanine. These base pairs are held together by a hydrogen bond, a type of chemical reaction that s easy to break and easy to reform. The statement is “DNA is a double helix made of two strands linked together with hydrogen bonds.”
Describe the process of speciation. include in your discussion the factors that may contribute to the maintenance of genetic isolation.
The process of speciation is the separation of a specific population into different species. The factors that may affect to maintain this genetic isolation are: allopatric, sympatric, prezygotic and postzygotic barriers. Allopatric barriers occurs when two species that are of the same family before cannot go back to the way they were before unless a contact between the two is established again. Sympatric are a group of species that shared the same family before but forced to evolve separately due to environmental factors. Prezygotic barriers are a group of species that are formed from the developing fertilized egg.
why do scientists believe that life first emerged from the ocean and onto land well after the ancestors of modern day cyanobacteria populated the earth
Answer:
Since the ancestors of modern day cyanobacteria added oxygen to the primitive reducing atmosphere of earth.
Explanation:
The primitive atmosphere of the earth did not have oxygen. So, life was not possible on land. The ancestors of modern-day cyanobacteria had the ability to carry out oxygenic photosynthesis which in turn releases oxygen as a by-product. Hence, these ancestors of modern-day cyanobacteria populated the land and added oxygen to the atmosphere of the earth.
Once enough oxygen was added to support the other life forms, aquatic life forms gradually started occupying the land habitats.
what element causes mars to appear red
Mars appears red due to the iron oxide in its soil, and its red hue is further accentuated by wind erosion dispersing fine dust particles.
The planet Mars appears red when viewed from Earth due to the presence of iron oxide, commonly known as rust, in its soil. Without the presence of liquid water, wind erosion plays a significant role in dispersing the fine dust particles that coat the Martian surface, contributing to its red hue. Mars is often associated with war and blood by ancient cultures, possibly influenced by its distinctive color. Mars's thin atmosphere is primarily composed of carbon dioxide, with a much lower atmospheric pressure compared to Earth, resulting in only a weak greenhouse effect and low temperatures.
The neck is a __________.
A. first class lever
B. second class lever
C. third class lever
D. fourth class lever
The neck is a fist class lever. Therefore, option (A) is correct.
What is a lever?Levers are formed by the coordinated action of skeletal muscles and cartilage. Levers are defined as rigid rods (often lengths of bone) that turn about a pivot point (usually a joint). It is possible to utilize levers so that a relatively weak force can move an extremely powerful force. This phenomenon is referred to as mechanical advantage.
People are able to accomplish more with less effort when they use levers. Objects can typically be moved or lifted with the use of a lever. It is sometimes used to push against items, however the objects are not truly moved by this action. One end of a lever can be used to apply a significant amount of force over a relatively short distance, while the other end of the lever can be used to provide a relatively modest amount of force over a significantly longer distance.
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Where does a bacterial cell store its dna?
A crossover in meiosis is an exchange of genetic material between
A crossover in meiosis is the exchange of genetic material between two homologous chromosomes during the prophase I of meiosis. This process adds to the genetic diversity of offspring.
Explanation:A crossover in meiosis is an exchange of genetic material between two homologous chromosomes. This process occurs during the prophase I stage of meiosis. Each chromosome aligns with its partner chromosome, and they exchange segments of their DNA in a process known as 'crossing over'. This results in chromosomes that have a mixture of both parent's genes and thereby adds to the genetic diversity of offspring.
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The myocardium receives oxygenated blood from the __________, which originate(s) from the __________.
The myocardium receives oxygenated blood from the coronary arteries, which originate from the aorta.
Explanation:The myocardium receives oxygenated blood from the coronary arteries, which originate from the aorta.
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______ causes diffusion of new water molecules out of the xylem and into the leaf.
1.Transpiration
2.Pollination
3.Photosynthesis
4.None Of The Above
Answer:
1. Transpiration
Explanation:
Transpiration is a physiological process by which plants lose water in the form of vapours through the aerial parts of a plant. Transpiration may be stomatal, cuticular or lenticular. But most of the transpiration is carried out through stomata. It is a wasteful process but it is necessary for the plants as it promotes water absorption and gives a cooling effect to the plants.
Juan believes that robins are a good example of a bird. sergei believes that penguins are a good example of a bird. juan and sergei are both correct according to the ________ model of organizing concepts.
Final answer:
Juan and Sergei are both correct according to the prototype model of organizing concepts, which suggests our minds organize concepts around prototypical examples, like robins for birds, but can still include less typical examples, like penguins.
Explanation:
Juan believes that robins are a good example of a bird, and Sergei believes that penguins are a good example of a bird. Both Juan and Sergei are correct according to the prototype model of organizing concepts. In psychology and cognitive science, the prototype model, first articulated by Eleanor Rosch, suggests that our minds organize concepts around prototypical examples. These prototypical examples embody the most common characteristics of a category but don't necessarily include all members of that category. Robins, for example, are seen as more prototypical birds because they exhibit characteristics commonly associated with birds, such as the ability to fly and build nests in trees. Penguins, while less prototypical, still fall within the bird category despite lacking these characteristics because they possess other defining bird traits, such as having feathers and laying eggs.
What is the difference between bactericidal and bacteriostatic agents?
The percentages of the daily values on food packages are given in terms of a person requiring _____ calories each day.
Answer:
27% I think, I'm not sure
Explanation:
The graph above shows the progress of an enzyme-catalyzed chemical reaction. Based on the graph, this enzyme
A. works optimally at 5°C
B. works optimally at 33°C
C. begins to denature above 25°C
D. begins to denature below 20°C
The right answer is C. begins to denature above 25°C
In biochemistry, denaturation is the process by which a biological macromolecule, nucleic acid or protein loses its normal three-dimensional conformation: the proteins lose their folding and unfold, the paired strands of the nucleic acid duplexes separate. This three-dimensional conformation is most often necessary so that the biological macromolecules can fulfill their function and thus the inactive denaturation in general these biological macromolecules.
Denaturation can be done by:
*Temperature: The increase in temperature causes thermal agitation of the atoms of the molecule. This causes a break in intermolecular interactions.
*PH change
*Radiation
*Chemical agents: chaotropic agents, bases, acids, reducing agents, detergents, heavy metal ions.
Ocean gyres can _________. Select all that apply. A. make hot climates cooler B. make hot climates warmer C. make cool climates cooler D. make cool climates warmer
Answer:
Option (A) and (D)
Explanation:
Ocean gyres are the system of oceanic water circulation that occurs due to the prevailing wind patterns and the forces that are initiated by the rotation of the earth. This continuous motion of ocean gyres forms a conveyor belt that circulates the water from the equatorial to the polar regions in both the hemisphere. It maintains the overall temperature, amount of nutrients, and the salinity of the ocean water.
These ocean currents are diverted towards the right by the Coriolis force that occurs due to the earth's rotation.
The ocean in the equatorial region is warmer than the water at the higher latitudes. It is because of the higher amount of sunlight that falls in this region. At higher latitudes, the temperature is relatively low and there the waters are much colder.
These ocean currents circulate in both the hemisphere, carrying the hot and warm water from the equator to the polar region and in return, carries the cold water from the polar to the equatorial region.
Thus, it can replace a hot climate by a colder one and a cold climate by a hotter one.
Hence, the correct answers are an option (A) and (D).
If a man's vas deferens is surgically cut and tied off how will it affect him?
Answer:
Vasectomy is a surgical procedure which is used for male sterilization. In this procedure vas deference of male is cut and tied so that the sperms cannot enter into the urethra.
This will not the process of fertilization and this is a very effective way of birth control. This is very economical method of birth control and less time taking process.
What theory suggests that our body's dna genetic code contains a built-in time limit for the reproduction of human cells?
What consequences of heavy drinking do men and women experience differently? select all that apply?
Which part of a nucleotide contains genetic information?
Answer:
nitrogenous base
Explanation:
the order of the bases in the structure determines genetic code. each base has an instruction. so, nitrogenous bases.
The Paleocene epoch left a thin layer of rock that is extremely rich in ______ fossils.
1.Fish
2.Mammal
3.Fern
4.None Of The Above
What causes a plant to wilt? the cells die. the cells lose turgor pressure. the cells run out of sugar. the cells lose salt?
The people in a location in Florida depend on groundwater for their supply of drinking water. The groundwater in the location has been tested recently and the nitrate and phosphate levels have been found to be very high in the groundwater. What are people in the location most likely to do?
start drinking bottled water
reduce their water consumption
start storing rain water for drinking purpose
install water filtering equipment in their houses
Answer:
D
Explanation:
When receiving delivery it is important to _______?
Final answer:
When receiving delivery, it is important to check the accuracy and quantity of the items, inspect their condition, properly store them, and label and track the inventory.
Explanation:
When receiving delivery, it is important to check the accuracy and quantity of the items before signing for them. This helps to ensure that you are receiving exactly what you ordered and that there are no errors or missing items. Additionally, it is crucial to inspect the condition of the items upon delivery. If there are any damages or defects, it is important to document them and notify the supplier or delivery company immediately.
Properly storing the delivered items is another important aspect of receiving delivery. This involves organizing the items in an appropriate location, taking into consideration factors such as temperature, humidity, and any specific storage requirements. It is also important to label and track the inventory to ensure efficient and accurate inventory management.
In summary, when receiving delivery, it is important to check the accuracy and quantity of the items, inspect their condition, properly store them, and label and track the inventory.
One function of the gallbladder is to ____.
The gallbladder's primary role is to store and concentrate bile, a digestive fluid which helps in the digestion of fats in the small intestine. It releases bile when we consume a high-fat meal.
Explanation:The primary function of the gallbladder is to store and concentrate bile, a digestive fluid produced by the liver. Bile aids in the digestion of fats in the small intestine. When we consume a meal, especially one that is high in fat, the gallbladder contracts and releases this stored bile into the small intestine through a series of ducts, facilitating the digestion process.
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Describe ONE example of poaching that is prevalent in your area.
In two or more complete sentences, explain the relationship between climate change and the greenhouse effect.
The relationship between climate change and the greenhouse effect is that when the rate of the greenhouse effect may increase, it directly impacts the phenomenon of climate change in negative aspects.
What is Climate change?Climate change may be defined as significant and major changes in global temperature, precipitation, wind patterns, and other measures of climate that remarkably takes place over several decades or longer.
Climate is the long-term pattern of weather in a particular area. It can typically provoke global weather patterns due to human activities. It consists of changes that typically result from different factors, like deforestation, and the combustion of fossil fuels that stimulate an increase in greenhouse gases.
Apart from this, Global warming is one type of climate change, and it refers to the gradual increase in temperature of the surface of the Earth.
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Euglenoid chloroplasts resemble those of what?
Answer:
The correct answer is green algae.
Explanation:
Euglena is unicellular flagellate protists found in the freshwater rich in organic material.
They show both modes of nutrition that is heterotrophic and phototropic. Their phototropic mode is due to the presence of chloroplasts with three membranes which produce energy through photosynthesis.
The chloroplasts of Euglena resembles the chloroplast of green algae and thought to have evolved from green algae and not directly from blue-green algae or cyanobacteria as the third membrane of Euglena is originated from the plasmalemma of the symbionts.
Thus, green algae are the correct answer.
describe one examples of poaching that is prevalent in south Africa
Illegal hunting or killing of animals is poaching. There are many animals which are poached in many countries of the world.
South Africa is seen as the primary guardian of rhinos. But now poaching of rhinos in South Africa is the most disturbing trend which is horrifically increasing. Since 2008, poaching of Rhinos in South Africa is increasing rapidly every year.
Your friend says the helium in your birthday helium balloon comes from radioactive decays. what is your response?
Final answer:
Yes, the helium in your birthday balloon originally comes from the decay of radioactive elements such as uranium. This helium is trapped in natural gas deposits, extracted, and compressed into cylinders for various uses, including filling balloons.
Explanation:
Your friend is correct. The helium gas in your birthday balloon does indeed come from the decay of radioactive elements like uranium. In the earth's crust, uranium-238 and other radioactive elements undergo radioactive decay, releasing alpha particles. Each alpha particle consists of two protons and two neutrons, which is essentially a helium nucleus. Once these alpha particles capture two electrons, they become helium atoms. This process happens over millions and billions of years, and the helium produced can get trapped in natural gas deposits, which are then extracted and eventually filled into your balloons.
The process of getting helium into a balloon involves extracting it from the earth, where it has been generated through radioactive decay, and then storing it in large metal cylinders under high pressure. When you buy a helium-filled balloon, the seller fills it from one of these cylinders. The ability of helium to leak through the balloon material over time is due to its small atomic size, leading to the balloon deflating.