Answer:
Hey There!!
You can say that...
Oxygen was added to early earth’s atmosphere through PHOTOSYNTHESIS!
Explanation:
The introduction of organisms which respired with the Sunlight and CO2 through PHOTOSYNTHESIS had brought a change in the Earth's early atmosphere...
PHOTOSYNTHESIS produces OXYGEN as a waste product (it's not needed by the organism)
This Oxygen is then released into the atmosphere where it was either converted into OZONE or left to move around the rest of he atmosphere...
I HOPE THIS HELPS WITH YOUR WORK!
:D
Which eukaryotic organelle was thought that have evolved from symbiotic bacteria? Describe how this event took place.
Answer:
The hypothesis that eukaryotic cells evolved from a symbiotic association of prokaryotes—endosymbiosis—is particularly well supported by studies of mitochondria and chloroplasts, which are thought to have evolved from bacteria living in large cells.
Several scientists from different countries are asked to examine the results of an experiment before a journal will print it.
Which term best describes this step of the investigative process?
question
communication of results
peer review
experiment control
Answer:
peer review
Explanation:
In science, results or findings from an experiment are usually published in journals. However, before they can be published, they have to undergo series of confirmation. One way to do this is to have several other scientists examine the results before finally publishing it. This is called PEER REVIEW.
PEER REVIEW is the process whereby an article that is about to be published in a scholarly journal is reviewed by researchers or scientists from the same field of study as the original scientist in order to ascertain the quality and validity of the result or findings. A peer-reviewed article is deemed to be of a very high quality.
Answer:
C. Peer review
Explanation:
I did the test
Indicate the type of testing each sentence describes. 1. Chromosomes from a sample of cells are stained and analyzed microscopically. Karyotyping 2. A DNA probe that hybridizes to a particular gene can be used to determine if a gene is present, absent or altered. (Click to select) 3. Antibodies are used to detect the presence or absence of a protein. (Click to select) 4. The enzymatic activity of a protein can be assayed in vitro. (Click to select)
Answer:
1. Karyotyping
2. In situ hybridization
3. Immunological (immunoblotting)
4. Biochemical (enzyme assay)
Explanation:
Karyotyping is the procedure in which pictures of the chromosomes are taken in order to identify and classify them according to their sizes, lengths, centromere positions, banding patterns, etc. In karyotiping, the chromosomes are stained to be clearly seen under a light microscope. In situ hybridization is a technique where complementary DNA oligonucleotides (either DNA or RNA) are used as probes to localize a specific segment of nucleic acid in a histologic section. Immunoblotting (western blotting) is a sensitive assay where antibodies are used to mark a protein, thereby enabling the identification of target proteins by exploiting the recognition specificity mechanism between antigens and antibodies. An enzyme assay is a technique used to measure the consumption rate of a given substrate or its production rate over time. Enzyme assays can be classified into four types: initial rate, transient kinetics, relaxation and progress curve assays.
If you have a loss of antigen what happen to your body
Answer:
you would get sick time and time again
The angle subtended by stars in the night sky is orders of magnitude smaller than the acuity threshold you calculated in 1). Why are we able to see objects that are much smaller than the angle subtended by the gap in the acuity threshold experiment? (50 word max)
Answer is given below
Explanation:
we consider here gap in character size is 0.75 mm
and distance is 300 mm
so minutes of arc is = 0.85944
and
visual acuity is express as
V = standard view distance D ÷ distance at which each letter D' ................1
There is visual acuity under the eyes, on which the object cannot be determined Factor factor mainly determines refractive error and contrast angle brightness or brightness and duration of contrast and exposure The target resolution threshold is expressed as a small angle, which can reduce the distinction between important elements of the stimulus pattern such as a pair of dots. Relaxation is specified in terms of its angular sizeWhat are the four major categories of micromolecules? Describe the basic structures and the primary functions of each.
Answer:
There are four major classes of biological macromolecules (carbohydrates, lipids, proteins, and nucleic acids); each is an important cell component and performs a wide array of functions.
Explanation:
Termites are unable to digest some plant materials (fiber). Termite stomachs contain bacteria that digest the fiber in wood for the termites. In turn, the bacteria are provided with a hospitable environment to carry out their life processes.
Answer: The question is not complete, the completed part is which type of relationship is it.
MUTUALISM
Explanation:
MUTUALISM is a symbiotic relationship that exist between organisms in which both the organism benefit from the relationship and there is not loss.
It is MUTUALISM because, the termite benefited from the relationship because the bacteria help it to digest and break cellulose for easy absorption and the bacteria benefited by obtaining accomodation and feeding on the left over of termites.
The two organisms actually benefited from each other.
Answer:
The question is not complete, the completed part is which type of relationship is it.
MUTUALISM
Explanation:
Two closely-related insect species are being discovered. Scientist are focusing on how long it takes each to develop limb buds following fertilization. What evidence of evil outlook is this an example of
o Explanation:
o gecromo e oo rat
If a claim is mainly supported by anecdotal evidence (stories or claims by people), It is
likely
Answer:
Biased.
Explanation:
Anecdotal evidence is described as the evidence that is based entirely upon an individual's personal experiences or observations.
As per the question, a claim based on such evidence is most likely to be biased as anecdotal evidence is based on a limited selection of examples that either support or refute the claim but not supported by any scientific or statistical analysis. Due to this undue bias, anecdotal evidence is not considered reliable as it displays the personal opinion, feeling, or experience of an individual. Thus, it may be used to negate the general statements but not to support r substantiate a claim or argument.
What do comets and astroids have in common
Answer:
Asteroids and comets have a few things in common. They are both celestial bodies orbiting our Sun, and they both can have unusual orbits, sometimes straying close to Earth or the other planets. They are both “leftovers” — made from materials from the formation of our Solar System 4.5 billion years ago.
Explanation:
Why do classification systems change over time?
Scientists find new evidence in their studies,
Scientists use old methods of classification.
Scientists repeat experiments and find no changes.
Scientists find similar evidence to previous work.
Answer:
Classification system changes because the scientists find new evidence in their studies.
Explanation: The world is always changing and growing and dying as well as developing, so over time things change. For example, as you grow up do you stay the same? No, you notice the physical changes happening, well thats sort of like how the earth and its ways are always changing as well.
Classification systems change over time - Scientists find new evidence in their studies
Millions of plants, animals, and microorganisms are present on the earth. They have been identified by scientists, however, There are many new species are still being discovered around the world.
Scientists find new evidence and species that may have to change classification systems in order to manage new systematics and taxa or ranks.to classify these newly discovered species, with new characters, new systems of classification have to be devised every now and then.Thus, Classification systems change over time - Scientists find new evidence in their studies
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Sensory cells for hearing are located in the:______.
Answer:
cochlea
Explanation:
How do plates move relative to each other at convergent plate boundaries?
Answer:
The movement of the plates creates three types of tectonic boundaries: convergent, where plates move into one another; divergent, where plates move apart and transform, where plates move sideways in relation to each other.
Explanation:
Some snakes produce a powerful poison that paralyzes their prey. This poison is an example of
Group of answer choices
an adaptation
resistance
an abiotic factor
a reptile
Answer:
This poisonis an example of an aboitic factor
The poison is an adaptation, as it is an advantage acquired through natural selection that allows the the snakes to bring down and capture their prey. Therefore, option (A) is correct.
What is adaptation?In biology, there are three related definitions of adaptation. First, natural selection, a dynamic evolutionary process, adapts organisms to their environments, improving their evolutionary fitness. Second, it is a condition that the populace has attained along that process. Thirdly, it is a phenotypic characteristic or adaptive trait that has been preserved and has developed via natural selection and has a functional purpose in each individual organism.
One example of physiological adaptation is the poison a cobra snake produces to defend itself against bigger creatures. They catch their victim using the poison as well.
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Which statement describes a scientific theory
Answer:
here
Explanation:
A scientific theory is an explanation of an aspect of the natural world that can be repeatedly tested and verified in accordance with the scientific method, using accepted protocols of observation, measurement, and evaluation of results. Where possible, theories are tested under controlled conditions in an experiment.
The body stores excess fat in nephrocytes.
a. True
b. False
Answer:
Verdadero
Explanation:
ALMACENA GRASA BLANCA
The statement "The body stores excess fat in nephrocytes." is false because excess fat is stored in the adipose tissue.
What is fat?Fat is a waxy substance that is made up of esters of fatty acids. It is necessary for body structural growth, but excess fat causes weight gain and many diseases.
Adipose tissues are found under the skin cell and under the cell of internal organs. They develop due to the accumulation of fats, they are also called fat cells. It is also called energy reservoirs.
Nephrocytes are present in the kidney, and they function as storage of excretory material. They do not store excess fats. Excess fat is stored by the adipose tissue in the form of triglycerides. The fat produces energy at the time of need.
Thus, the statement is false.
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1. The Devonian period is considered the Age of Fishes. Would you expect
to find a tetrapod (animal with four legs) fossil closer to the
Carboniferous period or the Silurian period? Why?
Answer:
You would find one closer to the Carboniferous period.
Explanation:
You would find them closer to there because all life started out in the ocean and it took several eras for the land creatures to develop legs and the first era to have them is the Permian era and towards the end of the Carboniferous period. While the Silurina era was much earlier then both and still heavily influenced by crustaceons and other such sea creatures.
Since the first tetrapods appeared at the end of the Devonian period, it is expected to find tetrapods fossils closer to the Carboniferous than to the Silurian period.
--------------------
The paleozoic era goes from 570 to 250 ma ago.
The era is composed of the following periods
CAMBRIC (570-490 ma)ORDOVICIC (490-443 ma)SILURIAN (440-400 ma)DEVONIAN (400-360 ma)CARBONIFEROUS (360-290 ma)PERMIC (290-250 ma)SILURIC (440-400 ma)
Gondwana was already formed. Laurasia was in its formation process
This is a recovery stage after the big massive Ordovician extinction.
Trilobites diversification and occurs bivalves' radiation.
The first gnathostomes appear.
First records of terrestrial vascular plants ⇒ small and with no supporting structures, inhabiting the water margins.
DEVONIAN (400-360 ma)
There are new adaptative strategies that separate even more the marine environment from the terrestrial one. Age of FishesDefinitive colonization and diversification of species in the terrestrial environment.During this period, among other events, emerged the lineage that would later originate tetrapods, by the end of the period. The first Ichthyostega emerges, which could be the ancestor of amphibians.Expansion and diversification of plantsFirsts terrestrial arthropods emerged. Coevolution with plants started. A big massive extinction occurred at the end of the period that severely affected the marine environment. Occurs a gradual replacement of terrestrial plants.
CARBONIFER (360-290 ma)
Begins Pangea formationThere is an ecological rechange in the ocean after the extinctionAmphibians emerge on the ground.The first reptiles appear as anapsids, synapsids, diapsids.Complete independence from water. There was a diversification of horsetails and tree ferns, pro-gymnosperms, and gymnosperms.Insects proliferation.
According to this information, by the end of Devonian period the firsts tetrapods appeared.
During the Carbonifeous period, after the devonian massive extinction amphibians and reptiles appeared.
These sequences indicate that tetrapod fossils are closer to the Carboniferous period than the Silurian period.
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Where are semilunar valves to be found in a mammalian heart?
Answer:
at the base of the aortic and Pulmonary trunk
Explanation:
Structurally the mammalian heart is made up of blood vessels for the empty of the blood from the heart chambers -the ventricles. Due to the forceful contraction of the blood against gravity into theses vessels,there are tendency for the back flow, from the vessels back into the ventricles.
These may lead to mixing of deoxyganted with oxygenated blood.
Aorta is the largest artery in the heart.It takes oxygenated blood from the heart into the systemic circulations.To prevent the back flow of the pumped blood after the L.ventricular systole,layers of valves shut up,and stop the flow of blood back into the ventricles.. These are the semilunar vlaves at the bases of the Aorta. The sound produced by this shutting up is called the dupp sound.
Likewise deoxygenated blood flow into the pulmonary circulation en-route the lungs is transported by the Pulmonary trunks.Therefore to prevent the back flow of the deoxygenated blood back into the pulmonary trunk, thes semilunars valves are closed,after R. ventricular systole
These two valves ensures that R and L Ventricular contraction for the ejection of oxygentated and deoxygented blood occurs without backlow and therefore no mixing of the two types occurs.
10. How do photosynthesis and cellular respiration differ?
O a. Photosynthesis uses food and cellular respiration produces food
О
b. Photosynthesis gives off oxygen and cellular respiration uses oxygen
c. Photosynthesis uses oxygen and cellular respiration uses carbon dioxide
d. Photosynthesis breaks down carbohydrates and cellular respiration produces them
Answer:
B
Explanation:
Photosynthesis involves the use of energy from sunlight, water and carbon dioxide to produce glucose and oxygen. Cellular respiration uses glucose and oxygen to produce carbon dioxide and water.
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SKILL:
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Why does surface tension occur?
How are rhizomes involved in asexual reproduction of ferns?
Answer:
The sporophytes of ferns grow through the rhizome
Explanation:
The gametophyte are responsible for sexual reproduction in plants while the sporophytes are usually responsible for asexual reproduction in plants.
Sporophytes are found in the rhizomes of plants and they help in the asexual reproduction.
This is how rhizomes are involved in asexual reproduction of ferns
The hormone oxytocin aids the birth process by stimulating:__________
Answer:
The hormone oxytocin aids the birth process by stimulating: uterine wall contractions.
Explanation:
Oxytocin is a hormone that is released naturally in the body of women and that intervenes in certain physiological processes, activating behaviors at a mechanical level in specific organs such as the uterus and the breasts. In the case of the uterus, oxytocin stimulates and maintains the contraction of the smooth muscle of the uterus during labor and delivery, that is, it is responsible for the existence of contractions, which occur during intercourse, due to the distension of the uterus that occurs produced during labor.
In order to prepare an optimal heat-fixed bacterial smear for staining, one must be aware of a couple of factors that may lead to poor results; briefly explain these. Why is it necessary to heat fix a smear for simple staining?
Answer:
The answer is below
Explanation:
Some of the factors that may lead to poor results in an optimal heat-fixed bacterial smear for staining are the following:
1. Thickness of the smear: In a situation whereby the smear is too thick, it would be impossible to perform adequate decolorization.
2. Quantity of Decolorizer: if the quantity of the decolorizer or reagent is concentrated, the quality of the stain will be affected
3. Age of the culture: Older cultures have multiple ruptured and dead cells, which result in staining Gram-negative.
4. Duration of Decolorization: Overheated smear during heat fixing, often leads to the rupture of cell walls.
The reason it is necessary to heat fix a smear for simple staining is that:
Heat fixing affects bacterial enzymes original state, which hinders their cell digestion parts, thereby leading to the breaking of the cell. The heat also improves the steadfastness of bacterial cells to the slide.
It is essential to heat and fix a smear for simple staining as it helps the bacteria to get attached with the slide. However, one must also be aware of the factors, which may lead to poor results.
What is heat fixation?It is a laboratory method used commonly in histology, cell biology, and pathology in which a slide with a specimen like bacteria is passed via the source of heat for many times.
It is an essential step in the procedure of staining as the heat fixation denatures the bacterial enzymes that can autolyze the cells of bacteria, therefore, to inhibit this there is a need to heat fix the smear. The heat fixation also enhance the attachment between the bacteria and the glass of slide so by which one can witness the smear clearly under the microscope.
Apart from these, there are some factors, which can result in poor results. Like when mixing bacteria with water, if one overmix, it can lead to inaccurate cell patterns. At the time of heat fixing, if one hold the slide over the flame for long duration, one would incinerate the cells.
Thus, heat fixing is important for the proper attachment of the bacterial cells with the slide and for proper visibility of the smear. One should also be careful about the factors, which may lead to poor results.
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Explain why a plant cell needs a cell wall but an animal cell does not. Feel free to add an image to support your explanation.
HCl is added to a solution containing barium and calcium ions. If a precipitate is formed, what is it? A. No precipitate is formed B. Barium chloride
Answer:
A. No precipitate is formed.
Explanation:
Hello,
In this case, considering that both calcium chloride and barium chloride are CaCl₂ and BaCl₂ respectively, due to their high polarity by cause of the ionic bond they have between calcium and chlorine and barium and chlorine we say they are highly soluble in water, therefore, A. No precipitate is formed.
Best regards.
4. Why are the results of the survey most likely unreliable?
Answer:
See the answer below
Explanation:
The results of surveys are most likely unreliable because surveys generally deal with questions that require value judgements or reporting beliefs. Consequently, there is no way to ascertain the objectiveness of responders and in most cases, responses are often biased.
Most survey questions are themselves inherently biased and only honest responses can make their results to be reliable. Unfortunately, there is no way to determine the veracity of responses. However, the unreliability of surveys reduces as the number of responders to the survey increases.
In an experiment, a scientist decides to study the effect of exercise on cholesterol levels in people. He studies two set of people—those who exercise every day for an hour and those who don’t exercise at all. In this case, the statement that people who exercise for an hour may have lower cholesterol levels is .........
. To test this statement, the scientist would measure cholesterol levels in exercisers and non-exercisers. The cholesterol levels would be ........
.
In the mentioned case, the statement that the people who has the exercise for an hour may have lower levels of the cholesterol has the hypothesis, and the cholesterol levels in the experiment would be the dependent variable.
What is hypothesis?A hypothesis has the suggested statement, that has been based upon the previous information, and has been used as an initiation point in the scientific investigation.
Any scientific experiments that comprise two variables, that it has dependent and the independent variables. The independent variable that refers to the variable, which has controlled or the modified in the scientific experiment in order to determine the influence on the dependent variable.
Scientific hypotheses, in the general, are the premises within the given theory, which can be the validated on the basis of the scientific method, contributing to the formulation of the new hypotheses.
Therefore, the cholesterol levels would be a dependent variable.
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all of the cell theory? (4 points)
Oa
Every living thing is composed of cells.
Ob
c
Cells come from pre-existing cells.
Cells are the basic unit and structure of all living things.
Od
Every cell has a nucleus that contains genetic material.
What are two ways bacteria and protists can be helpful to people?
