Answer:
Key points
Humans—and other complex multicellular organisms—have systems of organs that work together, carrying out processes that keep us alive.
The body has levels of organization that build on each other. Cells make up tissues, tissues make up organs, and organs make up organ systems.
The function of an organ system depends on the integrated activity of its organs. For instance, digestive system organs cooperate to process food.
The survival of the organism depends on the integrated activity of all the organ systems, often coordinated by the endocrine and nervous systems.
Introduction
If you were a single-celled organism and you lived in a nutrient-rich place, staying alive would be pretty straightforward. For instance, if you were an amoeba living in a pond, you could absorb nutrients straight from your environment. The oxygen you would need for metabolism could diffuse in across your cell membrane, and carbon dioxide and other wastes could diffuse out. When the time came to reproduce, you could just divide yourself in two!
However, odds are you are not an amoeba—given that you're using Khan Academy right now—and things aren’t quite so simple for big, many-celled organisms like human beings. Your complex body has over 30 trillion cells, and most of those cells aren’t in direct contact with the external environment.^1
1
start superscript, 1, end superscript A cell deep inside your body—in one of your bones, say, or in your liver—can’t get the nutrients or oxygen it needs directly from the environment.
How, then, does the body nourish its cells and keep itself running? Let's take a closer look at how the organization of your amazing body makes this possible.
Multicellular organisms need specialized systems
Most cells in large multicellular organisms don't directly exchange substances like nutrients and wastes with the external environment, instead, they are surrounded by an internal environment of extracellular fluid—literally, fluid outside of cells. The cells get oxygen and nutrients from this extracellular fluid and release waste products into it. Humans and other complex organisms have specialized systems that maintain the internal environment, keeping it steady and able to provide for the needs of the cells.
Different systems of the body carry out different functions. For example, your digestive system is responsible for taking in and processing food, while your respiratory system—working with your circulatory system—is responsible for taking up oxygen and getting rid of carbon dioxide. The muscular and skeletal systems are crucial for movement; the reproductive system handles reproduction; and the excretory system gets rid of metabolic waste.
Because of their specialization, these different systems are dependent on each other. The cells that make up the digestive, muscular, skeletal, reproductive, and excretory systems all need oxygen from the respiratory system to function, and the cells of the respiratory system—as well as all the other systems—need nutrients and must get rid of metabolic wastes. All the systems of the body work together to keep an organism up and running.
4. Which statement best expresses a basic scientific
assumption?
A Interpretation of experimental results has
provided explanations for all natural phenomena.
B) Ifa conclusion is valid, similar investigations by
other scientists should result in the same
conclusion.
C) For any conclusion to be valid, the design of the
experiment requires that only two groups be
compared
D) After a scientist formulates a conclusion based
on an experiment, no further investigation is
necessary
3
Answer:
Choose B) B) If conclusion is valid, similar investigations by
other scientists should result in the same
conclusion.
Explanation:
List the features of the gaseous exchange surface in humans.
Answer:
they give the lungs a really big surface area.
they have moist, thin walls (just one cell thick)
they have a lot of tiny blood vessels called capillaries.
Hopes this helps :D
Cell walls are only found in animal cells.
Answer:
False
Explanation:
Animal cells do not have a cell wall
Answer:
i think so yes beacuse i remember it that i read in in science
A closed system:
A. exchanges matter
and energy with other
systems.
B. exchanges
information and energy
with other systems.
C. is the most common
type in nature.
D. exchanges no matter
with other systems.
Answer:
D. exchanges no matter with other systems.
Explanation:
When you think of closed, think of something like a closed circuit. Nothing is effecting it from the outside and is not that common in nature. Most biological organisms are open systems such as us humans.
questions.
Questions
1 a Name the microorganism which causes the disease smallpox.
Answer: Variola Virus
Explanation:
Hair samples can provide information on all of the following EXCEPT.....
a
Age
b
Gender (sex)
c
Race
d
Hair samples can provide information on all of these.
Answer:
the answer should be A) Age
What is the best definition of excretion?
The elimination of undigested food.
Crying
The process of eliminating metabolic wastes.
Drooling
C) The process of eliminating metabolic wastes
15 POINTS!!!! At a molecular level, does plasma have more or less energy than other states of matter?
Answer: Hello!
Plasma is more energetic than other states of matter.
Explaination:
Mark me brainest please Hope I helped! Hope you make an 100%
-Anna♥
in what situation can a harmful deletion in a chromosome persist in a population?
Answer:
If the homologous chromosome lacks the deletionHow do you think caffeine will affect the heart rate of humans
Answer:
Caffeine stimulates the heart's contractions via acting on enzymes in the heart. Caffeine can help natural hormones operate on the heart to release norepinephrine, which has a stimulating impact comparable to adrenaline.
8. I contain pigments to capture light energy.
O Chloroplast
O Mitochondria
O I Both chloroplasts and mitochondria
Answer:
a/1 chloroplast
Explanation:
chloroplasts hold green pigment
identify the small facial bones found in the medial wall of the orbit.
Answer:
Lacrimal
Explanation:
I WILL GIVE 50 BRAINLY POINTS AND BRAINLIEST TO BEST ANSWER!!!
Choose a scientist to research and write about from this list:
John Dalton J. J. Thomson
Marie Curie Ernest
Rutherford Henry Moseley
Niels Bohr Werner
Heisenberg Erwin Schrödinger
James Chadwick
Which scientist will you write about? Explain why you made that choice.
pt 2
When writing a scientific paper, look for the most credible sources. Science doesn’t show bias, but we humans tend to show bias. There are sites and articles that provide facts without proper scientific evidence. Avoid using information from such sites. You must be able to identify reliable sites so the data in your paper is credible.
Use sources that end in .gov (government sites), such as OSTI.gov. They are reliable sources. You can also use sites ending in .edu. They can be deemed trustworthy, but som
Answer:
I'm going to write about John Dalton because it seems interesting that he observed that water evaporates and becomes a gas that mixes with air.
Explanation:
hope this helps :)
Demonstration 4: Universal Solvent
Materials needed:
-1 cup of water
-1 tsp of Salt, sugar or kool aid
Most of us have mixed water with salt, sugar or kool aid before. If you have not, give it
a try.
Questions:
1. What is the solute(s) in this experiment?
What is the solvent in this experiment?
This picture of a water molecule is drawn incorrectly. How could it be corrected?
Answer:
Solutes in this experiment are salt, sugar, or kool-aid
The solvent in this experiment is the water.
What is the most venomous snake in the world? Please help ASAP! Help would be appreciated. I will give Brainliest!
Note: it's my homework! :)
The most venomous snake in the world is Inland Taipan.
Answer: Oxyuranus microlepidotus, also called the fierce snake
Explanation: The snake with the most deadly venom.
NOT MY WORK I FOUND IT ON https://www.britannica.com/list/9-of-the-worlds-deadliest-snakes
Which fact from "Solar Conjunction: When the Sun Gets in the Way" would be LEAST important to include in a summary of the blog post?
- The Solar Conjunction period starts around April 4, 2013, and lasts until May 1, 2013.
- During this time, science observations are suspended.
- Without accurate measurements, the Mars Reconnaissance spacecraft cannot perform precise targeted science observations.
✅One Mars year is about 1.9 Earth years.
Answer: One Mars year is about 1.9 Earth years
Explanation: One Mars year will take around 687 Earth days.
Answer:
d
Explanation:
got it right on the test
identify the general location of the zygomatic arch.
Answer:
Identify the general location of the zygomatic arch. cheek. The zygomatic arch is a bony bridge formed between the zygomatic and temporal bones. ... The temporal process of the zygomatic bone and the zygomatic process of the temporal bone fuse to form the zygomatic arch.
Explanation:
possible
answer
importance of agriculture to the nation
The importance of agriculture is that if there will be no national resources in a country than the people of the country will migrate because lack of agriculture
I hope this will help you
Give an example of a 1) solid, 2) liquid and 3 gas.
1) Rock
2.) Acid
3.) Helium
I hope this is what you wanted
1. Brick
2. Water
3. Lava
Cereal crops - eg simple question free
Answer:
Important cereals are wheat, rice, maize, oat, barley, rye, millet and sorghum.
Answer:
Explanation:
some cereals are wheat, rice, maize, oat, barley, rye, millet and sorghum.
help help help help help
Answer:
D. There is a warm front coming from the south.
What has very thin walls to allow the nutrients and gasses to be exchanged between the blood and cells?
ОООО
Arterioles
Venules
Veins
Capillaries
Answer:
Arterioles
Explanation:
Arterioles are considered as the primary resistance vessels as they distribute blood flow into capillary beds. Arterioles provide approximately 80% of the total resistance to blood flow through the body.
when storing fruits and vegetables in her apartment, what steps can julie take to minimize nutrient losses? check all that apply.
Nutrient loss is the reduction or elimination of the nutrients in food. Nutrients are very important in the development of cells in the body and also giving energy and vitality to the bones.
Please note that your question is incomplete, so i am giving you a general overview.
Some of the factors that leads to nutrient loss in food includes:
Overcooking (exposure to high level of heat)FreezingDrying, etc.Therefore, to minimise nutrient loss, it is vital that food is well preserved and is finished immediately, to reduce or totally eliminate the need to freeze, overcook or reheat food.
Read more here:
https://brainly.com/question/19596918
Describe how the structure of an atom determines it's function. How is the structure of
an atom related to the properties A displays when bonding or reacting with other
atomslelements. Provide a simple example,
Answer:
Atoms consist of three basic particles: protons, electrons, and neutrons. The nucleus (center) of the atom contains the protons (positively charged) and the neutrons (no charge). The outermost regions of the atom are called electron shells and contain electrons (negatively charged).
Explanation:
Hope This Helps!
In spring, sugar solution rises quickly up through the phloem in plant stems . Give a reason for this
Answer:
Because phloem transports minerals and other solute. particles from lower parts to the stem in bidirectional manner. That is why in spring sugar solution rises quickly through phloem in plant stem
nombre de el tejido conjuntivo que se encarga de recibir el oxígeno
English mo Po Kase Hindi ko maintindihan
where are muscle cells found?
are short explanation please.
Muscle cells are found on the wall of the heart and blood vessels, visceral organs and remains attached to bone of the skeleton by tendons.
1. describe the stages of the cell cycle
2. use a model to illustrate the role of cellular division in the formation of new cells
3. describe the structure of a chromosome
4. follow chromosomes through the processes of mitosis and cytokinesis
Answer:
1.The cell cycle, or cell-division cycle, is the series of events that take place in a cell that cause it to divide into two daughter cells.
2. In the Picture Linked.
3. Chromosome help ensure that DNA is replicated and distributed appropriately during cell division. Each chromosome has a centromere, which divides the chromosome into two sections – the p (short) arm and the q (long) arm.
4. Mitosis occurs at the sites of growth and development of new tissues. Here are the stage of mitosis Below:
Prophase
This is the initial phase. The chromosomes in the nucleus become visible as thin coiled threads. In animals, the centrosome found in the cytoplasm divides to form two centrioles. The chromosomes become tightly coiled and shorter. From each centriole, fine fibers develop and elongate to form spindle apparatus. The nucleolus becomes dispersed in the nucleus and disappears. The nuclear membrane also break and disappears.
Metaphase
The pairs of chromatids align along the equator of the spindle apparatus and are attached to it at their centromeres.
Anaphase
The centromere of each chromosome splits and the chromatids separate. Each chromatid moves to the opposite poles of the cell. The chromatids appear as V--shaped.
Telophase
The spindle fibers disintegrate and disappear. New nuclear membrane forma around each set of chromatids. A nucleolus develops in the nucleus of each daughter cell. The cytoplasm now divides in a process called cytokinesis. In animals, an invagination develops at the plasmalemma near the equator of the cell.
Relationship between mitosis and cytokinesis:
Mitosis is the division of a nucleus. Cytokinesis is the division of the cytoplasm. If mitosis occurred without cytokinesis, the cell would contain two nuclei and twice the DNA. If cytokinesis occurred without mitosis , one of the new cells would lack DNA and a nucleus altogether.
What are things that sound waves can travel through?
Answer:
Sound waves are longitudinal waves. They need a medium to travel through. They cause particles of the medium to vibrate parallel to the direction of wave travel. The vibrations can travel through Solids, Liquids or Gases.
Explanation:
Hope it helps
please please help me i will give brainliest
What are the products of the light reactions used for during in the dark reactions of photosynthesis?