In Leonardo da Vinci’s time, nobody knew that the arteries were joined to the veins by tiny, invisible capillaries. This means that even though he studied the heart in detail, he thought that the arteries and veins were dead ends. Why did this make it difficult for him to understand how the heart worked?

Answers

Answer 1

Answer:

It was difficult for him to understand how the heart worked because he wasn't fully aware of the pumping mechanism of the heart and how the circulation of blood goes inside the body. Not seeing the capillaries meant that the heart pumped blood towards the vessels and into a dead end. He couldn't understand where the blood that was being pumped goes to.

Explanation:

Leonardo da Vinci is considered one of the earliest persons to study the heart. Although he made an exceptional observation of the different parts of the heart, he couldn't track the capillaries. He didn't know that these tiny structures connected the arteries and the veins. He believed that the heart was meant to transfer heat from the liver going to the muscles. He also believed that the lungs helped cool the blood.


Related Questions

What molecule promotes guanosine monophosphate synthesis to regulate the balance of nucleotide pools?
A) ATP
B) UTP
C) CTP
The structures of hypoxanthine and allopurinol are shown above. It is known that allopurinol is an inhibitor of the enzyme xanthine oxidase. What type of inhibitor is allopurinol likely to be?
A) Uncompetitive
B)Competitive
C)Allosteric

Answers

Answer:

Well the answer is A: ATP

Explanation:

A bird catches and tries to eat a caterpillar. The caterpillar has a bad taste, so the bird lets the caterpillar go. The next time it sees the same kind of caterpillar, the bird avoids eating it.

Which best describes this behavior?

Answers

The Monarch Butterflies contains chemicals in its body that make it taste bad to birds. The birds learn that if they eat these Butterflies that they will have a bad taste.

Answer:

The caterpillar has a bad taste, so the bird lets the caterpillar go.

Explanation:

Please help me I do not know how

Answers

Liquid 1 and 4, because they have the same melting point and density.

electrons are the electrons in the outer energy
level of an atom that can participate in interactions with other
atoms.
Check it

Answers

Answer:

Valence

Explanation:

In an atom, the electrons at the outermost energy level is called as valence electrons. It is the valence electrons which participates and interacts with the other atoms and form bonds. The valence electrons of an atoms are important as they depict the chemical properties of an element.

Thus the valence electrons resides the outermost shell and surrounds the atomic nucleus.

Transformation is the process by which a bacterium
O A. lies dormant in a cell for many weeks
B. adds DNA taken in from its environment
C. switches to the bacterial lytic cycle
D. injects its DNA into another bacterium
SUBMI

Answers

Answer:

adds DNA taken in form its environment.

Answer:

adds DNA taken in from its environment

Which two types of stars will enter the supernova phase?

Average and Massive Stars

Average and Supermassive stars

Massive and Supermassive Stars


Neutron and Red Stars

Answers

Answer: Massive and Supermassive stars

please help I need help!! I will mark brainliest if correct (if I can figure out how)

Answers

Answer:

it should be a) force = mass x acceleration

Explanation:

how does nature show emotion

Answers

Answer:Article

Authors

Metrics

Comments

Media Coverage

Abstract

Introduction

Study 1

Results

Discussion

Study 2

Results

Discussion

Study 3

Results

General discussion

Supporting information

Author Contributions

References

Reader Comments (0)

Media Coverage (0)

Figures

Abstract

Feeling connected to nature has been shown to be beneficial to wellbeing and pro-environmental behaviour. General nature contact and knowledge based activities are often used in an attempt to engage people with nature. However the specific routes to nature connectedness have not been examined systematically.

Explanation:

1. Provide two examples of why coral reefs are important ecosystems on Earth.
2. Some corals in the warm pools off Ofu Island can withstand temperatures of 32° to 34 °C without bleaching. So, the researchers set up a controlled laboratory experiment to try to determine why these corals survive in such excessive heat. With regard to the experimental design, provide two reasons why Dr. Palumbi devised a standardized test for the corals.

Answers

Answer:

It provides shelter and protection.

Explanation:

Coral reefs are very important to our ecosystems on Earth because it provides shelter to a large population of ocean life and also provide protection to coastlines from strong ocean currents and high waves from causing damage. Dr. Palumbi devised a standardized test for the corals in order to find out that why coral reef can withstand temperatures of 32° to 34 °C without bleaching.

Answer

Dr. Palumbi devised a standardized test for the corals in order to find out that why coral reef can withstand temperatures of 32° to 34 °C without bleaching.

Explanation:

In the answer

in chemical reactions, bonds blank in reactants.

Answers

in chemical reactions, bonds break in reactants

The movement of organisms from one place to another is called ___________. *

Answers

Answer:

Dispersal

Explanation:

Fishes excretory product?

Answers

The excreatory product of fishes is ammonia.

Help ASAP
thanks...............

Answers

1. Aurora
2. Ion
3. Thermosphere
4. Troposphere
5. Stratosphere
6. Ionosphere
7. Mesosphere
8. Ozone
9. Ozonosphere

Answer:

1. Ozone :- Form of oxygen having three atoms of oxygen to a molecule.

2. Mesosphere :- Later of the atmosphere just above the stratosphere.

3. Stratosphere :- The layer of atmosphere just above the troposphere where the temperature remains fairly constant.

4. Thermosphere :- The layer of atmosphere above the mesosphere where temperature are the highest in the atmosphere.

5. Ozonosphere :- Region in the upper stratosphere where the ozone is concentrated.

6. Aurora :- Streamers and band of light appearing in the sky at night , especially in polar region.

7. Ionosphere :- Layer of atmosphere containing ions; above the stratosphere.

8. Ion :- An electrically charged atoms.

9. Troposphere :- The layer of the atmosphere nearest the Earth in which most weather changes occur.

What is an allele frequency?

Answers

Answer:

the meaning of allele frequency is representing the incidence of a gene variant in a population

Explanation:

Each of the following about cells and the cell cycle is true except

A. Cells divide more often during growth
B. The cell cycle is regulated by both internal and external factors
C. Cells divide only when touching other cells
D. Different cells divide at different rates

Answers

Answer:

i think iam not sure it is C

C. Cells only divide when touching. in fact if the cell is surrounded on all sides by other cells it will not divide at all. hope this helps:)

What is the role of energy in living organisms? Is ti a mor or less important role than other characteristics of life?

Answers

Answer:

A huge number of chemical reactions take place continuously in a living cell. The whole of all chemical processes, that is, the total turnover of matter and energy is called metabolism.

Explanation:

All organisms need the energy to grow, reproduce, and respond to their surroundings. All these processes are achieved through metabolism that allows the energy available to them.

How are breathing and cellular respiration similar? Both involve using ATP to fuel other chemical reactions. Both use oxygen and produce carbon dioxide. Both involve breaking down glucose to produce ATP. Both require water in order to take place.

Answers

Answer:

A. Both involve using ATP to fuel other chemical reactions.

Explanation:

Answer:

Both involve using ATP to fuel other chemical reactions.

Explanation:

Megalodon left an awful lot of teeth behind, but don't worry. It is likely that it had plenty of extras. Like modern sharks, Megalodon had several rows of teeth. Scientists believe that Megalodon had six rows of 7-inch-wide, razor-sharp teeth, top and bottom, for a total of 276 teeth in its giant jaws! It's no wonder, then, that this ancient shark left so many of them behind. Without this trail of teeth, we would not know that these enormous creatures swam the ancient oceans as a top predator.Select two sentences from below that best show that the author wants the reader to be able to relate Megalodon's size to everyday life




A.What would you expect a creature whose name means “big tooth” to look like?
B.The Megalodon shark deserves this title.
C.As the Greek roots mega- (“big”) and don (“tooth”) suggest, this awesome prehistoric creature certainly did have huge teeth—as well as a massive and powerful body.
D.Scientists estimate that these gigantic sharks stretched as long as 60 feet.
E.If you're having trouble imagining that, just think of a school bus, typically about 45 feet in length.
F.Now, imagine a shark just a bit larger than that school bus—with 7-inch teeth.
G.Yes, this ancient fish certainly earned the prefix mega!
H.Since these sharks are extinct, how do we know exactly how huge and powerful the Megalodon shark was?

Answers

The answer is D and F. I did the test

Schizophrenia:
A. cannot be treated.
B. cannot be cured but can be treated.
C. can be cured with treatment.
D. is very common.
SUE

Answers

Answer:

B

Explanation:

cannot be cured but can be treated.

What might happen to your local hydrosphere and geosphere if conditions in the atmosphere caused rain for several weeks?

Answers

Answer:

the hydrosphere(bodies of water)would cause floods and other natural disasters while the geosphere will become infertile and landscape change (weathering).

Explanation:

Describe what are the roles of producers, Consumers, and decomposers in an ecosystem?

Answers

Answer:

"How might different types of organisms--producers, consumers, decomposers--be important to a healthy ecosystem?" (Producers change energy into matter with chemical energy that other organisms can use and then consumers pass the matter and energy on to other organisms by eating and being eaten; decomposers recycle some ...

Explanation:

Which organ is found in the digestive system?


heart


lungs


stomach


kidneys

Answers

Answer:

Stomach

Explanation:

Answer:

stomach.    :)

Explanation:

trust me this is the right anwser the one up is right and i also toke the quiz.    :)

The unit states that any animal that can be domesticated probably already has been. Explain the logic behind the statement and whether or not you find it convincing.

Answers

Answer:

Saying that if an animal can be domesticated that it probably already has been is saying that a lot of things are documented and if it has the capability to be domesticated or brought under human control then someone somewhere probably has. So I would personally find this convincing.

Explanation:

Hope that this helps and if so please mark me the brainliest. Peace and Love

Why do girls get more girls? (genetically, not because "their girls and normally get long hair")

Answers

Answer:

wdym? I'm confused

Explanation:

Answer: girls have the gene to get pregnant and give birth

Explanation: what are you even asking

Are you talking about how girls get more babies or?

If yes then girls have the gene to get pregnant and give birth

What is an organ system? Choose one of the organ systems and list the organs that belong to that system, as well as the system’s function.

Answers

Answer:

An organ system is a group of organs that work together as a biological system to perform one or more functions. Each organ does a particular job in the body, and is made up of distinct tissues.

1 circulatory system.

Circulates blood around the body via the heart, arteries and veins, delivering oxygen and nutrients to organs and cells and carrying their waste products away.

Keeps the body's temperature in a safe range.

Answer:

There are ten major systems in the organ system.

One Example:

renal system, in humans, organ system that includes the kidneys, where urine is produced, and the ureters, bladder, and urethra for the passage, storage, and voiding of urine.

Explanation:

A system is an organization of varying numbers and kinds of organs so arranged that together they can perform complex functions for the body. Ten major systems include the skeletal, muscular, nervous, endocrine, cardiovascular, lymphatic, respiratory, digestive, urinary, and the reproductive system.

Please give the answer for this!

Answers

for the first picture the stimuluis is light and the respons is phototropism(the plant is oriented towards the source of the light)

for the second picture the stimulus is the signt and smell of the food. the respons is salivary secretion

Answer:

1.

Stimulus: The light

Response: The plant gets light energy required to function

2.

Stimulus: The food in the bowl

Response: The dog digests the food absorbing nutrients needed to continue operating.

Hope this helps, feel free to give brainliest :)

Sponges, members of the phylum Porifera, are sessile filter feeders that lack tissues or organs. Instead, specialized cells have unique functions like ingesting food, support, and reproduction. Such specialization within a sponge body is a result of
A) cytokinesis.
B) cell cleavage.
C) cell differentiation.
D) gamete fertilization

Answers

Answer:

C) cell differentiation.

Explanation:

Cell differentiation is a process undergone by a cell in which it changes to a specialized form. During the process of cell differentiation, some genes in a single cell becomes turned off or on in a process called GENE EXPRESSION to give rise to cells with specialized functions.

This is the case of this sponge whose specialized cells perform unique functions like ingesting food, support, and reproduction. The specialization of the cells within the sponge is as a result of the process of CELL DIFFERENTIATION.

What is the percent by mass of a solution that contains 3g of salt in 12 g of solution?

Answers

Answer:

25% salt

Explanation:

(3÷12)×100

=25%

In a plant, leaf color and leaf shape are controlled by two linked genes. Leaves of the wild plant are red (R) while a recessive mutation in this gene causes leaves to be white (r). Wild-type leaves are pointed (P), while a recessive mutation in this gene causes them to be smooth (p). For a parent plant that is heterozygous for both traits with both recessive mutations on one chromosome, what genotypes will its gametes be

Answers

Answer:

The genotypes of the gametes are:

RP (parental), rp (parental), Rp (recombinant), rP (recombinant)

Explanation:

Available data:    

Leaf color and leaf shape are controlled by two linked genes.Leaves of the wild plant are red (R) while a recessive mutation in this gene causes leaves to be white (r).Wild-type leaves are pointed (P), while a recessive mutation in this gene causes them to be smooth (p). Parent plant heterozygous for both traits with both recessive mutations on one chromosome

Parent) RP/rp ---> RP are in one chromosome, while rp in another  

                             chromosome

Gametes) RP (parental)

                rp (parental)

                Rp (recombinant)

                rP (recombinant)


Explain how a motor neurone is specialised to allow it to carry out its function in the nervous system.

Answers

motor neurons need 4 u to eat appropriate lean proteins is what determines its function in the human body..The NS is an automatic system..If not eating right, ..m Neurons: carry messages away from the brain, spinal glands, they make muscles move.. The perifial Ns, made of nerves and carry messages 2 the brain..called neuromuscular junction. specialized, thru DNA from both parents...

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