Why is the structure of dna called a double helix?
a.because each of the curved dna subunits appears twice whenever it appears
b.because dna is made of two strands of nucleotides wound together in a spiral.
c.because two copies of dna are inherited, one each from the mother and father
d.because the number of copies of dna doubles with each round of pcr submit for grading save and finish later?
A membrane that allows only some materials to move in and out of the cell is _____.
permeable
semipermeable
rigid
bilayered
A biologist studying alpine wildflowers notices that two populations of similar species are able to occupy the same niches. However, species A is mostly found at lower altitudes, while species B is mostly found at higher altitudes. What has most likely caused the realized niches of these two wildflower populations to be smaller than their fundamental niches?
Species A and B have different altitudinal preferences due to competitive exclusion and resource partitioning, which leads to their realized niches being smaller than their fundamental niches. This minimizes competition, allows coexistence, and can drive speciation.
Explanation:In understanding why species A and species B, while having similar ecological niches, tend to occupy different altitudinal ranges, we must look to the concept of competitive exclusion and resource partitioning. The competitive exclusion principle states that two species that contest for the exact same resources cannot coexist at constant population values if other ecological factors remain constant. One of the species will either be pushed into another niche or become extinct. In this case, while species A and B could potentially have the same fundamental niche, the differences in altitudinal preference indicate a realized niche that has been shaped by competition and environmental pressures.
Over time, these pressures, including competition for resources and differing environmental conditions, have caused species A and species B to evolve adaptations suited to their respective ranges. This can lead to speciation, the emergence of new species as populations diverge genetically. Species A, adapted to lower altitudes, and species B, adapted to higher altitudes, thus minimize competition by occupying slightly different niches—which allows them both to survive without direct competition.
How does each snp affect the amino acid sequence of the insulin protein?
"receptors for polar molecules are found ____ while receptors for nonpolar molecules are located ____."
What conditions created the numerous fossils that make up the Burgess Shale?
The answer is : Mudslides instantly buried marine organisms in sediment.
( I got this right on a quiz ) (^○^)
Which two organisms are most closely related?
A. Euryarchaeotes and diplomonads
B. Brown algae and dinoflagellates
C. Brown algae and red algae
D. Euglena and brown algae
Which is the end result of cytokinesis?
Answer:
The end result of cytokinesis is one cell physically divides into two cells.
Explanation:
The process of the M- phase of cell division, by which 1 cell divides into 2 cells is the cytokinesis. Cytokinesis takes place after the karyokinesis. It normally follows nuclear doubling. It occurs in both mitosis or in meiosis.
Plant cell cytokinesis is different from the animal cytokinesis because of cell wall rigidity. Plant cells forming cleavage furrow, cell plate arises a double cell wall for both daughter cells. Cytokinesis is the final stage of the cell division or cell cycle.
Thus, the end result of cytokinesis is one cell physically divides into two cells.
which type of wetland is constantly submerged in water and contains trees ?
A wetland refers to a different ecosystem, which is flooded by water, either seasonally or permanently, where the oxygen-free procedures exist. The main element, which separates wetlands from the other water bodies or landforms is the characteristic vegetation of aquatic plants, amended with the specific hydric soil.
Swamp refers to a wetland ecosystem featured by mineral soils with poor drainage and by plant species dominated by trees. The swamps are found all through the world, most usually in low-lying regions with poor drainage adjacent to rivers that supply the swamp with water. Some of the swamps develop from marshes, which gradually fill in, permitting woody shrubs and trees to develop.
... Swamp ... (Apex)
Which is not a temperature control?
Answer:
nitrogen
Explanation:
any factor that causes temperature to vary from time to time and place to place. how do the heating of the land and water differ? land heats much faster and to a higher temperature, and cools much faster and to a lower temperature.
What is the main result of photosynthesis
Answer: glucose
Explanation:
Animals that have their body parts arranged around a central point are A. spherically symmetrical. B. bilaterally symmetrical. C. radially symmetrical. D. asymmetrical.
Animals with body parts arranged around a central point are radially symmetrical. This structure is common in species like starfish and jellies, where any slice through the central axis produces mirrored halves.
Explanation:Animals that have their body parts arranged around a central point are C. radially symmetrical. This form of symmetry is common in several species, particularly those from the cnidaria and echinoderm group, which includes jellies and starfish, respectively. In radially symmetrical animals, any slice passing through the central axis will divide the organism into mirrored halves. Unlike bilateral symmetry (seen in humans, for instance), where only one plane can divide an organism into two virtually identical halves, radial symmetry allows for multiple planes of division.
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about two-thirds of a cell is composed of water what is the name of the process in which water moves into or out of the cell membrane to maintain homeostasis
I think it is Osmosis
Explanation:
Answer:
Osmosis
osmosis is the movement of water across a membrane from higher to lower concentration.
How many different genotypes are possible in any single mature spermatocyte of a man who is heterozygous at a single gene locus for a specific trait?
The law of similarity can account for grouping of stimuli that are similar in
The answer is orientation, shape, and pitch audition. The transition of two closely proximate stimuli through a neuron is often interspersed by delays. This is because the neuron has to repolarize before it can carry another impulse. This also leads to the belief that the human operator also processes information intermittently (in a discontinuous servo). Therefore, according to the law of grouping, stimuli that happen so closely together of simultaneously are often merged into a single decision response by the central nervous system based on the principles of Proximity, Similarity, Continuity, Closure, and Connectedness.
What is the distinction between interphase mitosis and cytokinesis?
During self pollination in seed plants pollen grains
Self-pollination takes place when the pollen from the same plant arrives at the stigma of a flower or at the ovule. There are two kinds of self-pollination, that is, autogamy and geitonogamy.
In autogamy, pollen is moved towards the stigma of the similar flower. While in geitonogamy, pollen is moved from the anther of one flower to the stigma of another flower on the similar flowering plant, or from microsporangium to ovule within a monoecious gymnosperm.
Which of the following are characteristics of K-selected species? More than one answer
A. Early maturing
B. Large size
C. Long life expectancy
D. Few offspring
Large size, long life expectancy and few offspring are all characteristics of K-selected species.
What are K-selected species?K-selected species are those species of organisms which possess stable populations fluctuating near the carrying capacity of the environment.
These species are also characterized by
Long gestation periodLong lifespanShowing high parental care.Some examples of K-selected species are:
HumansElephantsBirdsHorsesBisonsLearn more about living organisms:
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Roles of rna in protein synthesis in eukaryotes rna plays important roles in many cellular processes, particularly those associated with protein synthesis: transcription, rna processing, and translation. drag the labels to the appropriate bins to identify the step in protein synthesis where each type of rna first plays a role. if an rna does not play a role in protein synthesis, drag it to the "not used in protein synthesis" bin.
A nurse on an inpatient medical-surgical unit is taking care of a patient with acute gastritis. the patient has a nasogastric tube (ngt) to low-intermittent suction with bilious aspirate. upon reassessment, the nurse finds the aspirate to have become blood-tinged. what should the nurse do next?
Sadie was prescribed betaxolol ophthalmic drops by her ophthalmologist to treat her glaucoma. oral beta blockers should be avoided in patients who use ophthalmic beta blockers because:
I believe the correct answer is that ophthalmic beta receptors are addictive and have drastic effects on the cardiac cells.
Explanation:Both ophthalmic beta blockers and oral beta blockers target the beta receptors that can be found in the heart. They do not act antagonistic to one another and use of ophthalmic beta blockers concurrently with the oral beta blockers will multiply the effect of the drugs and the person will experience heart failure.
Further Explanation:The human central nervous system is divided into the Central Nervous System which involves the brain and spinal cord and the Peripheral Nervous System that involves the rest of the body. The Peripheral Nervous System is further divided into the Somatic Nervous System and the Autonomous Nervous System (ANS). The ANS is controlled involuntarily by the brain and involves functions such as respiration and the cardiac rhythm including contraction and relaxation of blood vessels. The ANS has specific receptors that the CNS uses to produce the response and they include the α (alpha), β (beta) and D receptors. The beta receptors are usually divided into the beta 1 and 2. Beta 1 receptors are found exclusively on the heart and Beta 2 receptors are found on blood vessels and the bronchioles. Beta blockers bind to the two β1 and β2 blockers to produce an effect such as Betaxolol which is a cardioselective β1 blocker that lowers blood pressure by acting on the heart and slows the cardiac rhythm. Oral beta blockers will bind antagonistically to both β1 and β2 and binds to both heart receptors, blood vessels and the bronchioles. Using both oral and ophthalmic beta blockers will result in excessive antagonism and the heart will slow until it stops and the blood pressure will go down excessively and the lungs will also not function properly leading to hypoxia. The results will then prove to be fatal.
Level: College
Subject: Pharmacology
Topic: The Autonomous Nervous System
What is the role of ATP synthase in photosynthesis?
Answer:
It uses the potential energy of flowing hydrogen ions to make ATP
Explanation:
Answer: it uses potential energy of flowing hydrogen ions to make atp
Explanation:
In northern Canada, a population of rabbits was predominantly white in color. The allele for white color is recessive (g), while the allele for gray color is dominant (G). Over the last several decades, the average annual temperature of this area has increased, and the long-term deposits of ice and snow have become scarce. We see the result of this change in the graph above. How would Hardy-Weinberg explain this change in terms of allelic frequency? A) No population can maintain equilibrium indefinitely. B) Random mating occurred among the rabbits and the allelic frequency was altered. C) Genetic variation existed. Natural selection occurred. Allelic frequencies changed. D) In a large population, mating is random, without mutations and the allelic frequency changes over time.
Answer:
The correct answer would be C) Genetic variation existed. Natural selection occurred. Allelic frequencies changed.
Hardy-Weinberg law states that the allelic frequency of a population remains constant generations over generations in absence of evolutionary factors such as selective breeding, natural selection, genetic drift et cetera.
In the given scenario, natural selection has taken place due to the which the allelic frequency of a population changes over time.
In the original population, the allele frequency of g would be higher as it would have given the survival advantage when long-term ice deposits were used to present.
However, in absence of ice, the white fur would not be beneficial as it would be easily detected by predators.
Thus, the allele frequency of g would decrease in a population and with the help of natural selection the allele frequency of G would increase in the population.
Thus, the allele frequency of a population changes as a result of natural selection.
1, Explain the endosymbiotic theory of the origin of eukaryotic cells in your own words.
2, Compare at least two characteristics of mitochondria to prokaryotic cells and explain how this relates to the endosymbiotic theory.
3. Describe an example of endosymbiosis that has been observed and documented.
1. The endosymbiotic theory proposes that eukaryotic cells, which are more complex than prokaryotic cells, originated through a mutually beneficial relationship between different types of simpler prokaryotic cells.
2. Characteristics of mitochondria that support the endosymbiotic theory include their similar size and shape to free-living prokaryotic cells, the presence of their own DNA (circular, like prokaryotic DNA), and the fact that mitochondria divide independently of the host cell.
3. An example of endosymbiosis that has been observed and documented is the relationship between certain corals and photosynthetic dinoflagellates called zooxanthellae. These dinoflagellates live inside the coral cells.
1. According to this theory, an ancestral eukaryotic cell engulfed smaller prokaryotic cells (likely a bacterium) and instead of digesting them, formed a symbiotic relationship. Over time, these engulfed cells became specialized organelles within the host cell, such as mitochondria and chloroplasts, responsible for energy production and photosynthesis. This theory suggests that eukaryotic cells with their membrane-bound organelles, like the nucleus, evolved from this cooperative relationship between host and endosymbiont.
2. These characteristics suggest that mitochondria were once free-living aerobic bacteria that were engulfed by an ancestral host cell. Over time, they evolved into specialized organelles for energy production within the eukaryotic host cell, much like their bacterial ancestors.
3.The coral provides protection and a stable environment for the zooxanthellae, while the zooxanthellae carry out photosynthesis, providing the coral with nutrients. This mutualistic relationship enhances the coral's ability to survive in nutrient-poor waters and helps create the vibrant colors seen in coral reefs. This real-life example illustrates how endosymbiosis can lead to a mutually beneficial partnership between two different organisms, similar to the concept proposed in the endosymbiotic theory of eukaryotic cell origin.
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What is the function of the aronium?
a.to produce eggs
b.to carry out asexual reproduction
c.to produce sperm
d.to absorb minerals and water
e.to anchor the roots?
In rails, what is the primary function of activerecord? (choose the best answer)
ActiveRecord in Rails is responsible for providing an ORM that allows developers to interact with the database using Ruby code. It simplifies database operations and eliminates the need to write SQL queries directly.
Explanation:The primary function of ActiveRecord in Rails is to provide an Object-Relational Mapping (ORM) between the application code in Rails and the underlying relational database. It allows developers to interact with the database using Ruby code, without having to write SQL queries directly. ActiveRecord provides methods and conventions for creating, querying, updating, and deleting database records, making it easier to work with databases in Rails applications.
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The growth of plants in some Arctic lakes has increased significantly in the past 150 years. Scientists attribute this increase in plant growth to the increase in surface air temperatures on Earth, also known as global warming. Which of the following best explains how global warming can cause an increase in plant growth in Arctic lakes?
Increasing air temperatures can cause an increase in the growing season of Arctic plants.
Which two of these processes remove airborne CO2 from Earth’s atmosphere?
1. photosynthesis
2. respiration
3. carbon sequestration
4. burning fossil fuels
Answer:
Photosynthesis and carbon sequestration
Explanation:
Photosynthesis is a natural way of fixing carbon into the organic molecules and carbon sequestration is an active artificial method of removing the CO2 gas from the atmosphere and store it in the reservoirs.
A
describes something in nature and predicts how it will behave without explaining why.
Answer:
Law
Explanation:
That is the answer just law or you will get it wrong
Through a process of _____, ADP is converted into ATP. dephosphorylation phosphorylation oxidation
Answer:
Phosphorylation
Explanation:
Phosphorylation is one of the metabolic stages of cellular respiration. It happens only in the presence of oxygen (aerobic beings), which is necessary to oxidize intermediate molecules and participate in reactions to form the ATP molecule and produce energy.
In the early stages of cellular respiration (glycolysis and Krebs cycle), some of the energy produced in the breakdown of compounds is stored in intermediate molecules, coenzymes such as NAD + and FAD +.
This oxidation energy of coenzymes is used for ATP synthesis. For this occurs phosphorylation of ADP, ie it receives phosphate groups. This is why this process is called Oxidative Phosphorylation.