____ are thought to be present before vertabrates

Answers

Answer 1

Answer:

Jawless fish was present before vertebrates.

Explanation:

Jawless fish has some characteristics of vertebrates and also considered as the ancestor of vertebrates on earth which is similar in appearance with the hagfish. It was present about 500 to 600 million years ago. They consist of cranium but vertebral column is absent. but with the passage of time, evolution occurs and many animals which was the descendant of this jawless fish having vertebral column or backbone in their body.


Related Questions

Assume that the allele for curly tail is completely dominant to the allele for straight tail for an X-linked maternal effect gene. Which of the following can be true?

a. In order for a female to be curly tailed, her father must be curly tailed.
b. A straight tailed male must have a straight tailed mother
c. mother with a straight tail cannot have progeny with curly tails
d. A male with a curly tail received a straight tail allele from his mother.

Answers

Answer:

A

Explanation:

In order for a female to be curly tailed, her father must be curly tailed.

Which statement best describes geothermal energy? Geothermal energy can be used to fuel vehicles. Geothermal energy increases the risk of a nuclear accident. Geothermal energy is the most abundant nonrenewable resource. Geothermal energy can be used as a source of electricity.

Answers

Answer:

Geothermal energy

Explanation:

can be used as a source of electricity. hope this helps you :)

Answer:

D

Explanation:

Bile is produced by which organ?
Select one:
a. Small intestine
O
b. Liver
c. Stomach
d. Gall bladder​

Answers

The answer is b liver

Which of the following would be most likely to increase erosion rates?
A. A coastline with a well defined beach.
B. Waves breaking at the foot of a cliff
C. Waves with a very long fetch (have traveled far).
D. All of these

Answers

Answer:

D

Explanation:

we all need that all of then helps to increase erosion rates

D

This is because all of these have a major effect on the erosion rates and over time you would see a major difference with all the factors in play

Match each part of Sammi's model to the bodily structure it represents. One bodily structure has already been labeled for you.

Answers

Answer:

corrugated cardboard tube - digestive tract

irregular surfaces on the corrugated tube - villi

pump - heart

Plastic tubing - blood vessels

Explanation:

The corrugated cardboard tube represents the digestive tract.  The give away was the presence of the irregular surfaces within the tubes. This is called the villi. The villi is responsible for the absorption of food after digestion into the body.

Irregular surfaces on the corrugated tube represent the villi. They are tiny hair-like structures that are in the small intestine, that are responsible for the absorption of food into the bloodstream.

The pump represents the heart. The heart is the only organ in the body that provides the pressure force that pushes the blood throughout the body. In this model, the pump will most likely be performing the same function.

The plastic tubings are meant to contain one form of fluid or the other. Judging from that, they can be said to represent the blood vessels. This is because they are connected to the heart and are meant to transport bodily fluids around the body

Answer:

corrugated cardboard tube - digestive tractirregular surfaces on the corrugated tube - villipump - heartPlastic tubing - blood vessels

Explanation:

Where does translation and transcription occur in prokaryotic cells? (1 point)
O nucleus
O cytoplasm
O ribosomes
ocell membrane

Answers

Answer:

Cytoplasm

Explanation:

Answer:

operon

Explanation:

Is lead renewable or not?

Answers

Answer:

it is not renewable.........

Answer:

Lead is not a renewable resource. It is a metal that forms naturally in the Earth, but it takes a very long time for metals to form.

Keeping in mind that a crayfish is saltier than the fresh water it occupies, and remembering the idea of osmosis, note that the antennal gland deals directly with the consequences of this issue. What do you suppose the function of the antennal gland is

Answers

In the antennal gland of the freshwater crayfish (Astacus), fluid is filtered from the blood into an end sac and passes through a tubular labyrinth, where ions are reabsorbed, to produce a hypotonic urine that passes via a renal tubule to the bladder.

Which of the following correctly describes the process of Translation? I. tRNA anticodon bonds to mRNA codon II. Ribosome bonds to mRNA strand III. Ribosome reaches a STOP codon and detaches from the mRNA IV. Each tRNA adds an Amino Acid to the chain as the Ribosome moves along the mRNA V. Complimentary mRNA strand is made from DNA template

Answers

Ribosome bonds to mRNA, a tRNA anticodon bonds to mRNA codon, tRNA add an Amino Acid and ribosome detaches from the mRNA describe translation (II, I, IV and III).

What is translation?

The translation is the cellular process by which cells can produce proteins by using the genetic code.

The translation involves the use of an mRNA sequence which contains codons that serve to add amino acids to the polypeptide chain in the ribosome.

In conclusion, the steps II, I, IV and III describe translation.

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Identify the effects of the vagus nerve on the following components of the digestive system Salivary glands Pyloric sphincter (gastric emptying) Smooth muscle in the gallbladder Smooth muscle in the duodenal papilla (sphincter of Oddi)

Answers

Answer:

Vagus nerve is the 10th cranial nerve. It is long start from brain and distributed over head, thorax and abdomen.

Explanation:

1.   In the salivary gland the secretory and vasodilator effect on afferent nerve is mediated mainly by parasympathetic reflex which is given by vagus nerve.

2.   Pyloric sphincter is the part present between the stomach and small intestine which regulate the flow of food particles from stomach to the intestine. Vagus nerve control the activities of pyloric sphincter. Vagus nerve help the pyloric sphincter to relax.

3.  Efferent nerves of vagus nerve help the gall bladder to contract. Vagus nerve is stimulating the gastric tract to contract. So the vagus nerve stimulation promotpromotprthe production of CCK hormone and it will lead to the contraction and secretion of hormones from the gallbladder. Those contractions will help the gallbladder to empty the hormones from gallbladder.

4.  The efferent nerves of vagus nerves act on the smooth muscles of duodenal papila. As above says it lead to the contraction of smooth muscles and also promote the production of CCK.

The bacteria Listeria monocytogenes is capable of doubling every 36 hours in the refrigerator at 4°C and can grow even when temperatures are less than 2°C. Therefore, L. monocytogenes is best classified as a psychrophile.
a. True
b. False

Answers

Answer:

True

Explanation:

Listeria monocytogenes is a psychrophilic food-borne pathogen that is problematic for the food industry. Structures of Csps from psychrophilic bacteria have not yet been studied.

Listeria is not killed by freezing. Growth is arrested altogether, but normal growth will be resumed after thawing.

Complete each sentence by putting the labels to the appropriate blanks. Then place each sentence in a logical order beginning with blood entering the right side of the heart.
a. Blood enters the right ventricle from the right atrium through the right atrioventricular valve which is also known as the_________.
b. From the left ventricle, the blood is pumped up to the___________ through the left semilunar valve which is sometimes referred to as the___________.
c. Beginning with the return from the systemic circulation, blood enters the________.
d. The right ventricle contracts next, which forces blood up through the right semilunar valve which is otherwise known as the__________.
e. After circulating through the blood returns to the_______.
f. From the left atrium, blood moves through the left________ which is also referred to as the________ or mitral valve.
1. bicuspid
2. tricuspid valve
3. right atrioventricular valve
4. right atrium
5. aortic valve
6. left atrioventricular valve
7. atrioventricular valve
8. pulmonary valve
9. left atrium
10. aorta
11. pulmonary capillaries
12. systemic capillaries

Answers

Answer:

c. Beginning with the return from the systemic circulation, blood enters the right atrium.

a. Blood enters the right ventricle from the right atrium through the right atrioventricular valve which is also known as the tricuspid valve

d. The right ventricle contracts next, which forces blood up through the right semilunar valve which is otherwise known as the pulmonary valve .

e. After circulating through the pulmonary capillaries, the blood returns to the left atrium.

f. From the left atrium, blood moves through the left atrioventricular valve which is also referred to as the bicuspid or mitral valve.

b. From the left ventricle, the blood is pumped up to aorta the through the left semilunar valve which is sometimes referred to as the aortic valve.

Explanation:

c. Beginning with the return from the systemic circulation, blood enters the right atrium.

a. Blood enters the right ventricle from the right atrium through the right atrioventricular valve which is also known as the tricuspid valve

d. The right ventricle contracts next, which forces blood up through the right semilunar valve which is otherwise known as the pulmonary valve .

e. After circulating through the pulmonary capillaries, the blood returns to the left atrium.

f. From the left atrium, blood moves through the left atrioventricular valve which is also referred to as the bicuspid or mitral valve.

b. From the left ventricle, the blood is pumped up to aorta the through the left semilunar valve which is sometimes referred to as the aortic valve.

Hãy mô tả các bước tạo thư viện cDNA từ tế bào máu heo.

Answers

Answer:

What you mean bro?

Explanation:

Which of the following does NOT describe telomerase? A. shortens the telomeres in cancer cells. B. present in embryonic cells. C. It stimulates cell division. D. It is an enzyme.

Answers

Answer:

option c is ur ANS mate .......

The role of the ___________ branch of the autonomic nervous system mediates control of organ processes when the body is essentially ______.

Answers

Answer: parasympathetic; at rest

Explanation: The parasympathetic nervous system branch of the autonomic nervous system is largely responsible for the relaxation of the body especially at rest where it undoes the activities of the sympathetic branch by decreasing respiration, heart rate and then increasing the body's digestion rate. As such, this branch is also responsible for digestion response in a relaxed, resting, or feeding states. The role therefore of the parasympathetic branch of the autonomic nervous system mediates control of organ processes when the body is essentially at rest.


The currently accepted model of the cell membrane was discovered by ________ in the year ______

A) Charles Overton, 1895
B) singer and Nicolson, 1972
C) Davison and Danielli, 1970
D) Irving Langmuir, 1917

Answers

Answer:   B

Explanation:  The currently accepted model of the membrane is the fluid mosaic model.  S. J. Singer and G. Nicolson proposed the fluid mosaic model in 1972.

The cell membrane model depicts the arrangement of the biological membrane and its component. The fluid mosaic model was given by Singer and Nicolson in 1972. Thus, option B is correct.

What is the fluid mosaic model?

The fluid mosaic model was discovered by Singer and Nicolson and is a widely accepted model for the structural organization of the plasma membrane and its components. It elucidates the mosaic of plasma components.

The proteins, lipids, and carbohydrates are the main components of the plasma membrane that are arranged and shows the fluid nature of the biological membrane.

Its arrangement and structure allow the semi-permeable nature and its role as the barrier. It shows the membrane is a lipid bilayer that includes the hydrophobic tail and the hydrophilic head.

Therefore, the fluid mosaic model was given by Singer and Nicolson.

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The dark bands seen under the microscope in a skeletal muscle fiber are concentrations of actin protein called l-bands . It is true or false.

Answers

Answer:

it is false

Explanation:

it appears as light bands under microscope

Answer:

false

Explanation:

because dark band seen under the microscope in a skeletal muscle fiber are concentration of actin protein  are known as A bands because they are anisotropic when viewed with polarized light

Why is it important to have a taxonomy or classification of types of collection and how does that help us understand the development of collection strategies, technologies, collection planning, and methods of collection

Answers

Answer:

Classifying and characterizing various types of collection helps us to identify and understand the capabilities and limitations of each type.

Explanation:

By understanding these factors, we are better able to request support, layer collections, and provide a complete collection plan that best addresses our intelligence gaps. Collection strategies ultimately start with these gaps. By understanding all of your available collection capabilities, you can more effectively manage these assets to accomplish the mission. In most cases, you will not be able to have every type of asset or collection medium under the sun, so it becomes even more critical to understand the strengths and weaknesses of those available. Doing so will help a collection manager most effectively utilize the assets available to them to accomplish the collective organizational mission or end state. Without characterization and classification, you cannot fully understand and thus employ the myriad of tools available effectively (Found on a site not mine)

Taxonomy allows us to organize and categorize collections based on their characteristics, which makes it easier to understand the various types of collections that exist and to compare them.

What is taxonomy?

All of the world's plants, animals, and microorganisms are included in taxonomy, which is the science of naming, describing, and classifying species.

For a number of reasons, taxonomy, or the classification of collection kinds, is crucial.

Secondly, taxonomy enables us to classify and organize collections based on their traits, which facilitates comprehension of the numerous sorts of collections that exist and allows for simpler comparison.

To ensure that collections are properly managed, preserved, and available for future generations, taxonomy is an essential tool for understanding the development of collection strategies, technologies, planning, and techniques of collecting.

Thus, it is important to have a taxonomy or classification of types of collection.

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Suppose you want to make a new connection to species in the concept map. Which of the terms below could fill in the blank in this new connection: "_____ is a mechanism that defines the separation between species." Select all that apply.

Answers

Answer:

Hello. You did not enter answer options, but some terms that can be used to fill in the blank are:

Hybrid infertility, Hybrid inviability, Behavioral isolation, Sympatric isolation, Habitat isolation, Hybrid breakdown, Allopatric isolation.

Explanation:

All of the above terms represent situations that cause separation between species. This separation can occur physically or molecularly, but it always results in genetic modifications that end up separating one species genetically from the other, causing evolution and generating different species, to the point that it is not possible to establish mating between its members.

During inhalation, the chest cavity _________ in volume, _________ the pressure in the lungs.

Answers

Answer:

1. reduce la presión interna

2. el aire se precipita hacia adentro y llena los pulmones.

Explanation:

The vector allows for protein expression in E. coli.

Briefly explain the role of the following elements in the context of gene expression and protein production:

1- LacP:

2- LacO:

3- LacZa:

4-Briefly explain and indicate what is required for high expression in E. coli in this context..

The vector also contains other important elements. Explain their role:

5- AmpR:

6- ori:

Answers

Answer:

1. Lac P or the promoter is the binding site for RNA polymerase, situated just upstream to the gene.  

2. Lac O or operator is a sequence situated just downstream to the sequence of the promoter at which binding of the repressor protein is done and ceases RNA polymerase enzyme from binding.  

3. Lac Z refers to the gene that encodes for protein beta-galactosidase, which further results in the formation of glucose and galactose from lactose.  

4. For high expression in E.coli IPTG is required. It attaches with the lac repressor and discharges the tetrameric repressor from the lac operator in an allosteric fashion, thus, permitting gene transcription in the lac operon.  

5. AmpR is also known as the ampicillin-resistant gene, which is utilized as a selective marker for selection against ampicillin antibiotic.  

6. Ori or the origin of replication refers to the sequence of the genome, which is accountable for the initiation of replication.  

Before using any chemical in the lab, why should one first read the Material Safety Data Sheet (MSDS)?
The MSDS provides information on safe handling of the chemical.
The MSDS explains where the chemical can be purchased.
The MSDS provides the chemical formula for the substance.
The MSDS describes how the chemical will react with other substances.​

Answers

Answer:

A

Explanation:

Took test on Edge.

Material Safety Data Sheet (MSDS) contains information related to occupational safety and health. The MSDS provides knowledge on the safe handling of chemicals. Thus, option A is correct.

What is MSDS?

Material Safety Data Sheet (MSDS) is the data safety sheet that states the rules and details of handling and using the laboratory chemicals that are related to health. It is of great importance as it allows the learning of chemical hazards.

Before entering the lab and using the chemicals one should read the MSDS book so to get aware of the handling and precautions that have to be taken while performing any experiments. To work safely one should know its danger and should be prepared for emergencies.

Therefore, the MSDS provides knowledge on the handling of hazardous chemicals.

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explain about Biogenetic theory?

Answers

Answer:

biogenetic theory mean the development and evolution processed by Ernst heackel in Germany in the 1860 s . it is one of the several recapitulation which posit that the stage of development for an animal embryo as the same as other animal or adults stage or forms.

What physical traits were favored in the peppered moth AFTER the Industrial Revolution?

Answers

Answer: Their skin color was dark which made the moths blend in. During the Industrial Revolution, the soot from factories caused the trees to become black. The light colored moths became easier to kill because they could not blend into their environment.

Explanation:

Based on the data table below, which number would be the BEST choice for the top number of the scale on the vertical axis of a scatter plot showing this data?

Answers

Answer:

D. 70

Explanation:

From the table given, we can easily tell that distance (m) is dependent on time (s). Distance is a dependent variable, while time is an independent variable.

If both variables were to be plotted to show the relationship between them on a scatter plot, the dependent variable is usually plotted on the vertical axis (y-axis), while the independent variable would be plotted on the horizontal axis (x-axis).

Distance would be in the vertical axis, while time would be in the horizontal axis.

Therefore, the BEST choice for the top number of the scale on the vertical axis would certainly be 70, because the highest value for distance (m) on the table of values is 69.

Based on your own investigation, what challenges do you think scientists face when classifying new organisms?

Answers

The main challenge that scientists face in classifying new organisms is that some organisms may show properties that are intermediate between the properties of known classes of organisms.

What is taxonomy?

Taxonomy is the hierarchical system whereby scientists classify organisms based on the characteristics of the organism. New organisms are studied and classified accordingly.

However, new organism may show properties that are intermediate between the properties of known classes of organisms thereby posing a problem for the classification of such organisms.

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1. Research 5 functions of the frontal lobe and explain them in detail with example.
2. Explain what you think might happen if someone damaged frontal lobe. You must mention the functions you have listed

Answers

Answer:

Solving a problem, memory, language, judgement,  social and sexual behavior.

Explanation:

5 functions of the frontal lobe are given below:

1) it control the expression of emotions.

2) it is responsible in solving a problem.

3) it also control the memory and language.

4) it helps in judgement.

5) it is responsible for social and sexual behavior.

If frontal lobe is damaged, the individual may lose its memory, judgement ability. the social and sexual behavior is also disturbed. It may lose the ability to solve a problem and also have language problem.


Please select the correct chorological order for the following events:
A. Treaty of New Echota, Black Hawk War Ends, Black Hawk War Ends
B. Black Hawk War Ends, Treaty of New Echota, Treaty of Fort Laramie
C. Treaty of Fort Laramie, Black Hawk War Ends, Treaty of New Echota
D. Treaty of New Echota, Treaty of Fort Laramie, Black Hawk War Ends
Reset Selection

Answers

Answer:

C treaty of fort laramie, black hawk war end, treaty of new echota

Drag the correct tiles to the box. Not all tiles will be used.
Identify the goods or animals that Europeans introduced to the Americas.
turkeys
wheat
corn
horses it is not horses because it said it was wrong

Answers

Answer:

the eupopeans introduced horse to the americans, as the native american living there already had turkeys,corn,and wheat.

Wall lizards are not seen during cold, Why?​

Answers

Wall lizard are not seen because blood becomes cold inside the body.

Answer:

Lizards are cold-blooded. They use their enviornment to control their body temperature. If a lizard is cold, it will go somewhere warmer. If a lizard is hot, it will go someone to cool off.

The lizard may find somewhere in direct sunlight, bury themselves in a hole, or bury themselves under leaves to keep warm.

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HELP ASAP The figure shows two parallel lines AB and DE cut by the transversals AE and BD. Which best explains the relationship between triangle ABC and triangle EDC? EHomework: PracticeExam 3Question 7Find the standard deviation for the group of data items.14, 15, 16, 16, 17, 18The standard deviation is(Simplify your answer. Round to two decimal places as needed.)9 This problem explores the behavior of charge on conductors. We take as an example a long conducting rod suspended by insulating strings. Assume that the rod is initially electrically neutral. For convenience we will refer to the left end of the rod as end A, and the right end of the rod as end B. In the answer options for this problem, "strongly attracted/repelled" means "attracted/repelled with a force of magnitude similar to that which would exist between two charged balls.A. A small metal ball is given a negative charge, then brought near (i.e., within about 1/10 the length of the rod) to end A of the rod. What happens to end A of the rod when the ball approaches it closely this first time?What happens to end A of the rod when the ball approaches it closely this first time?a. It is strongly repelled.b. It is strongly attracted.c. It is weakly attracted.d. It is weakly repelled.e. It is neither attracted nor repelled. evaluwate 5(14-2to the third power)+8/2 Which operation involving complex numbers requires the use of a conjugate to be carried out? What point is hurston trying to make in her first paragraph? Is she the only Negro in the United States whose grandfather on the mothers side was not an Indian chief? Net Present Value MethodThe following data are accumulated by Geddes Company in evaluating the purchase of $150,000 of equipment, having a four-year useful life:Net Income Net Cash FlowYear 1 $42,500 $80,000 Year 2 27,500 65,000 Year 3 12,500 50,000 Year 4 2,500 40,000 Present Value of $1 at Compound InterestYear 6% 10% 12% 15% 20%1 0.943 0.909 0.893 0.870 0.8332 0.890 0.826 0.797 0.756 0.6943 0.840 0.751 0.712 0.658 0.5794 0.792 0.683 0.636 0.572 0.4825 0.747 0.621 0.567 0.497 0.4026 0.705 0.564 0.507 0.432 0.3357 0.665 0.513 0.452 0.376 0.2798 0.627 0.467 0.404 0.327 0.2339 0.592 0.424 0.361 0.284 0.19410 0.558 0.386 0.322 0.247 0.162a. Assuming that the desired rate of return is 15%, determine the net present value for the proposal. If required, round to the nearest dollar. Use the table of the present value of $1 presented above.Present value of net cash flow $Amount to be invested Net present value $b. Would management be likely to look with favor on the proposal?Yes , because the net present value indicates that the return on the proposal is greater than the minimum desired rate of return of 15%. radio waves are electromagnetic waves that travel at the speed of light 300 000 kilometers per second what is the wave length of FM radio waves received 100 megahertz on your radio dial Comparing our modern society in the United States to that of ancient Mesopotamia, how have laws changed over time? At what rate must Uranium 235 undergo fission by neutron bombardment to generate energy at a rate of 100 W (1 W Ellie wants to double her savingsof $5000 by investing her moneyfor 20 years.What interest rate doesshe need to look for?Give your answer to 1 d.p. How long will it take a 6000W motor to lift a 5000kg load through a height of 2.5m? Who was appointed to write the Declaration of Independence? RADIOWAVES of constant amplitude can be generated with 1) FET2) filter 3)rectifier 4)oscillator How was the battle at Normandy a turning point in World War II? The Allied forces were defeated and retreated. The Axis forces succeeded in ambushing the Allied forces at Normandy. The Allied forces succeeded in pushing over one million Allied soldiers into France. The Axis forces had the advantage of the element of surprise. If you wanted to make your own lenses for a telescope, what features of a lens do you think would affect the images that you can see Which of these vegetables can erase pen marks?Cucumbers Mushrooms, garlic, onions A farmer sells 8.6 kilograms of apples and pears at the farmer's market. 4/5 of this weight is pears, and the rest is apples. How many kilograms of apples did she sell at the farmer's market? Which of the following statements best represents a Humanistic approach? a. He needs to discover it for himself. b. If we teach them the right way, they will follow it. c. She will never learn, shes not interested in learning. HELPP PLEASE Ill give a brainlist