An atom with an equal number of electrons and protons has no charge.
A fish maintains its depth in fresh water by adjusting the air content of porous bone or air sacs to make its average density the same as that of the water. Suppose that with its air sacs collapsed, a fish has a density of 1.18 g/cm3. To what fraction of its expanded body volume must the fish inflate the air sacs to reduce its density to that of water?
Answer:
0.153
Explanation:
We know the up-thrust on the fish, U = weight of water displaced = weight of fish + weight of air in air sacs.
So ρVg = ρ'V'g + ρ'V"g where ρ = density of water = 1 g/cm³, V = volume of water displaced, g = acceleration due to gravity, ρ'= density of fish = 1.18 g/cm³, V' = initial volume of fish, ρ"= density of air = 0.0012 g/cm³ and V" = volume of expanded air sac.
ρVg = ρ'V'g + ρ"V"g
ρV = ρ'V'g + ρ"V"
Its new body volume = volume of water displaced, V = V' + V"
ρ(V' + V") = ρ'V' + ρ"V"
ρV' + ρV" = ρ'V' + ρ"V"
ρV' - ρ"V' = ρ'V" - ρV"
(ρ - ρ")V' = (ρ' - ρ)V"
V'/V" = (ρ - ρ")/(ρ' - ρ)
= (1 g/cm³ - 0.0012 g/cm³)/(1.18 g/cm³ - 1 g/cm³)
= (0.9988 g/cm³ ÷ 0.18 g/cm³)
V'/V" = 5.55
Since V = V' + V"
V' = V - V"
(V - V")/V" = 5.55
V/V" - V"/V" = 5.55
V/V" - 1 = 5.55
V/V" = 5.55 + 1
V/V" = 6.55
V"/V = 1/6.55
V"/V = 0.153
So, the fish must inflate its air sacs to 0.153 of its expanded body volume
From fossil evidence, you know two species shared a common ancestor approximately 50 million years ago. In comparing a known neutral sequence between rats and mouse, you found 92 base differences in 1000bp. From this information, which of the following values is closest to what you would predict the mutation rate to be?
a. 1 x 10-9
b. 4 x 10-9
c. 2 x 10-9
d. 5 x 10-9
e. 5 x 10-8
f. 8 x 10-9
Answer:
Option c ([tex]2\times 10^{-9}[/tex]) is the correct alternative.
Explanation:
Given:
Common ancestor,
= 50 million years ago
Base differences,
= 92
Now,
The predicted mutation rate will be:
= [tex]\frac{92}{50\times 10^6\times 1000}[/tex]
= [tex]\frac{1.84}{10^9}[/tex]
= [tex]1.84\times 10^{-9}[/tex]
or,
= [tex]2\times 10^{-9}[/tex]
Thus the above solution is the right one.
1.La energía es la capacidad de un cuerpo para producir trabajo.
2.La energía se clasifica solamente en renovables.
3.Las ondas se pueden propagar en un medio o un espacio vacío.
4. Las ondas se pueden clasificar en longitudinales y transversales.
5. La energía cinética es aquella que se encuentra en movimiento.
6. El núcleo de la Tierra está formado
por metales, principalmente hierro y níquel, y en menor
cantidad por azufre y oxígeno.
7. La corteza terrestre está compuesta por rocas
8. La contaminación se puede
definir como la presencia o acumulación de sustancias en el medio ambiente
que afectan negativamente el entorno.
9. Los elementos de la tabla periódica se clasifican de acuerdo con sus propiedades y características
similares.
II. Escoge
1. Son fuentes de energías renovables:
2. Son fuentes de energías no renovables:
3. Partes de las ondas:
15. La ciencia que estudia los seres vivos es:
16. En la biotecnología se incluyen las áreas de:
17. Consiste en la liberación de sustancias químicas a la atmósfera que alteran su composición.
18. Se debe a la presencia de desechos en el agua. La contaminación de mares, ríos y lagos se produce por
las actividades del ser humano.
19. Se debe a la acción humana (los residuos y la basura arrojada en cualquier superficie terrestre).
20. Cuando el contaminante es una sustancia química que procede normalmente de los usos industriales.
21. Surge con la emisión de fluidos a elevadascontaminación.
22. La actividad humana produce mucho ruido, y los altos decibelios en un determinado lugar por encima de sus niveles naturales marcan la contaminacion.
Answer:
La actividad humana produce mucho ruido, y los altos decibelios en un determinó do lugar por encima de sus niveles naturales marcan la contaminación.
Explanation:
Creo que es la respuesta
A person infected with the Ebola virus will experience symptoms within 2 to 21 days of being exposed to the virus. During this time, the virus uses cell machinery to make copies of itself. Ebola symptoms include fever, severe headaches, vomiting, and unexplained bleeding or bruising The reproductive cycle of the Ebola virus that most likely causes symptoms within 2 days is - A lysogenic because the onset of the symptoms is delayed Blytic because the individual experiences symptoms very quickly after infection C lysogenic because the onset of symptoms occurs in individuals over 60 years of age Dlytic because the virus affects the circulatory system
Where would you be likely to find the alpine tundra biome?
a. the Russian north woods
b. central plains of the United States
c. the southern most tip of Australia
d. a mountain range in Europe
Answer:
The answer is D.
Explanation:
D- A mountain range in Europe
Alpine tundra is found on high-latitude landmasses, above the Arctic Circle like Russia, Greenland, Iceland, and Scandinavia. Thus option A is correct
What is alpine tundra?Alpine tundra is a type of ecosystem that occurs at high elevations characterized by colder temperatures, long winters, and growing seasons are shorter with no trees.
The Russian north woods have Treeless tundra and distinctive vegetation known as Beringian woodland, high mountain range, and long winter. so option A is correct.
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2. What is the main function of the a Reproductive System
to give birth to youg one
Freshwater ecosystems can be grouped as those that are still, those that are flowing, and those that contain salt.
Answer:
true
Explanation:
Compare and contrast the methods used by bacteria and protozoa to stay alive. Even when conditions within the environment are
unfavorable for the growth and survival of the organism.
Answer:
Protozoa formed cysts and bacteria produces endospores.
Explanation:
Protozoa can survive in dry and unfavourable environments, by producing resting cysts that enable them to remain dormant until conditions are favourable while on the other hand, bacteria produce special dehydrated cells called Endospore which helps the bacteria to survive unfavourable environmental conditions. These endospores help bacteria to resist high temperature, radiation, drying, and other environmental extremes.
What is the primary purpose of special-interest groups?
O A. To determine a person's social status
O B. To control the means of production
C. To teach people how to take care of themselves
D. To influence political decisions
Answer:
The answer is D. To influence political decisions
Explanation:
Which is an example of heterozygous genotype?
[A] AA
[B] Aa
[C] aa
Answer:
[B] Aa
Explanation:
Heterozygous genotype means "having two different alleles of a particular gene or genes." That would mean that the letters are different, so Aa.
Answer:
b because one is dominate and other is a hybrid
Explanation:
Can somebody help me out
Answer: HALF
Explanation:
CONTEXT CLUES AND I TOOK IT BEFORE
What is the distinctive feature of entrepreneurship?
A.
An entrepreneur gets funds from the government.
B.
An entrepreneur raises capital from the market.
C.
An entrepreneur only invests capital in the venture and has no decision-making power.
D.
An entrepreneur enjoys all the profits and absorbs the losses.
Answer: Option D.
An entrepreneur enjoys all the profits and absorbs the losses
Explanation:
An entrepreneur is someone who set up a business and also enjoy all the profits and bear its lose. An entrepreneur is an initiator of new things and procedures. He creates a new business using his on creative ideas, innovations and the proceedings to the involved. He is the sole contributor of ideas and capital involved.
which organ is responsible for helping to keep the water concentration equal on each side of the cell membrane?
(please help I've been stuck on this for 2 days)
Answer:
solute membrane
Explanation:
Kidney is the main organ which is responsible for helping to keep the water concentration equal on each side of the cell membrane.
What is Kidney?The kidneys are the main organs in the body which remove waste products and extra water from the blood in the form of urine and also help to keep the chemicals such as sodium, potassium, and calcium balanced in the body. The kidneys also secrete hormones which help control blood pressure and stimulate bone marrow to make red blood cells.
Kidneys maintain water concentration in the body. Kidneys maintain homeostasis through osmosis. Osmosis is the phenomenon of movement of water or fluid particles from a region of higher concentration to a region of lower concentration through a semi-permeable membrane.
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Which will form an ionic bond?
A. Two oxygen atoms
B. Two oppositely-charged ions
Ο Ο Ο
C. Any two neutral atoms
D. Two negative ions
Option B- Two Oppositely-Charged Ions
Hope This Helps You ❤️Elements in the same column of the periodic table of the elements all
A. have the same number of protons.
B. share the same atomic structure.
C. have similar physical characteristics.
D. share the same number of neutrons
Answer:
C
Explanation:
elements in the same column have different number of protons and different number of neutrons.
Elements in the same column of the periodic table of elements all share the same atomic structure. Thus, the correct option for this question is B.
What is the similarity in the elements that belong to the same column?Each column is called a group. The elements in each group have the same number of electrons in the outer orbital. Those outer electrons are also called valence electrons. They are the electrons involved in chemical bonds with other elements.
The number of protons governs the atomic number of an element. So, elements never have the same number of protons. The number of neutrons along with protons governs the atomic mass of an element which also never remains the same.
The physical characteristics of any element depend on the majority of the attributes. So, it may also vary from element to element.
Therefore, elements in the same column of the periodic table of elements all share the same atomic structure. Thus, the correct option for this question is B.
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at least seven ways fungi can be beneficial
Answer:
- Fungi are an important source of food.
- Yeast, a unicellular fungus,is important in bakeries as it is used in the making of bread.
- Yeast also produces vitamin B.
- Fungi, like bacteria,are also good decomposers.
- Penicillin an important antibiotic is obtained from a fungus called Pencillium notatum.
- fungi are responsible for breaking down organic matter and releasing carbon, oxygen, nitrogen, and phosphorus into the soil and the atmosphere.
- Fungi are essential to many household and industrial processes, notably the making of bread, wine, beer, and certain cheeses.
Explanation:
hope this helps ^_^
The human body is made up of several organ systems that work as a unit to allow the body to function properly. When the body is invaded by the E. coli bacteria from ingesting undercooked meat, a person will likely experience diarrhea, nausea, and vomiting. Which of the following system failed to do its job?
(I’ll give brainliest)
A. Digestive System
B. Excretory System
C. Nervous System
D. Immune System
cuál es el límite entre la cavidad torácica y abdominal?
Answer:
El diafragma es un músculo en forma de cúpula que separa la cavidad torácica (pulmones y corazón) de la cavidad abdominal (intestinos, estómago, hígado, etc.).
Explanation:
question on picture for biology
Answer:
water enteringthrough the lungs
Explanation:
hope it's correct
Answer:
water entering through the lungs
Explanation:
PLS HELP IM TIMED
Which human activity causes an immediate increase in the amount of greenhouse gases in the atmosphere?
A.
biological magnification
B.
burning fossil fuels
C.
deforestation
Answer:
b
Explanation:
On Earth, human activities are changing the natural greenhouse. Over the last century the burning of fossil fuels like coal and oil has increased the concentration of atmospheric carbon dioxide (CO2). This happens because the coal or oil burning process combines carbon with oxygen in the air to make CO2.
The increase in fossil fuel burning since mid-19th century is increasing the amount of CO2 in the atmosphere true or false
Answer:
true
Explanation:
this is a true statement.
Which factor is a major cause of global warming?
Answer: increased burning of fuels
Explanation:
could i perhaps get brainliest
Answer:A
Explanation:
PLEASE HELP! I WILL GIVE BRAINLIEST. Explain the process of succession.
Answer: Succession is a series of changes in the composition of an ecological community over time.
Explanation:
i hoped this helped
Please answer as many as you can this is just a study guide
Answer:
01. the continued existence of organisms that are best adapted to their environment, with the extinction of others, as a concept in the Darwinian theory of evolution.
02. It shrinks as species begin fighting for resources.
03. The animal will experience a lack of growth.
04. Level 1: Plants and algae make their own food and are called producers. Level 2: Herbivores eat plants and are called primary consumers. Level 3: Carnivores that eat herbivores are called secondary consumers. Level 4: Carnivores that eat other carnivores are called tertiary consumers.
Explanation:
How much time does it take to use 300 W of power to do 1800 J of work? Round your answer to the near
number.
SERE
The time is
S.
Answer:
the answer is 6 secs rounded to nearest ten is 10
Explanation:
hope it helps
Which model shows a way that large molecules can enter a cell without using
the cell's energy?
Answer:
C
Explanation:
There was no C and D on yours but here is a picture of my son's exam.
what is the long term impact on the environment from agriculture
Answer:
agriculture help the environment
Explanation:
Like in making of money and to prevent famine over a period of time
The characteristic of light waves that makes objects appear bent when placed in water is called
A.Reflection
B.interference
C.bending
D.refraction
Answer:
D: Refraction
Explanation:
A: Reflection is not when light goes through water. C: Bending is not the correct term used.
Earthquakes occur when:
A.the earth's plates rub against each other
B.magma squeezes through cracks in the crust
C.eroded sediment is carried away
D.heat and pressure build up under the surface
Answer:
B: magma squeezes through crcks in the crust
Explanation:
Lava (magma that has erupted onto the Earth's surface) is visually mesmerizing – as the molten rock flows downhill, lava exposed to the air cools to a deep black color, while the molten rock beneath glows bright orange.
im not sure ha but ok nadin yan
Match each immune cell with the method it uses to neutralize a pathogenic microbe that has infected a human - Cytotoxic T cell - Helper T cell - B cell - Natural Killer Cell - Macrophage - Mast Cell A. kills infected human cells after recognizing antigens displayed on MHC class 1 B. does not directly kill microbes; after recognition of a specific antigen displayed on MHC Class 2, it secretes molecules that help other cells to do so. C. phagocytoses microbes after recognizing specific antigens; secretes antibodies D. kills virus-infected human cells by releasing perforin and granzymes. E. Phagocytoses microbes after recognizing PAMPs; acts as an Antigen Presenting Cell to activate another type of immune cell F. Does not directly kill microbes; secretes histamine to initiate an inflammatory response.
Answer:
Cytotoxic T cell - kills infected human cells after recognizing antigens displayed on MHC class 1 B.
Helper T cell - does not directly kill microbes; after recognition of a specific antigen displayed on MHC Class 2, it secretes molecules that help other cells to do so.
B cell - phagocytoses microbes after recognizing specific antigens; secretes antibodies
Natural Killer Cell - kills virus-infected human cells by releasing perforin and granzymes.
Macrophage - Phagocytoses microbes after recognizing PAMPs; acts as an Antigen Presenting Cell to activate another type of immune cell
Mast Cell - Does not directly kill microbes; secretes histamine to initiate an inflammatory response.
Explanation:
T cell are immune-response cells that originate in the bone marrow but migrate and develop in the thymus gland. They are of two classes; Cytotoxic T cells and Helper T cells.
Cytotoxic T cell - kills infected human cells after recognizing antigens displayed on MHC (Major histocompatibility complex) class 1 B.
Helper T cell - does not directly kill microbes; after recognition of a specific antigen displayed on MHC Class 2, it secretes molecules that help other cells to do so.
B cells are formed and develop in the bone marrow. They make antibodies against antigens, and phagocytoses microbes after recognizing specific antigen.
Natural Killer Cells are cytotoxic lymphocytes of the innate immune system. They kill virus-infected human cells by releasing perforin and granzymes.
Macrophages are a type of white blood cells that detects and phagocytoses microbes after recognizing PAMPs (Pathogen-associated molecular pattern) They also act as Antigen Presenting Cell (APCs) to activate another type of immune cell
Mast Cells are cells found in the connctive and they function as part of the immune system of the body. They do not directly kill microbes. They secrete histamine to initiate an inflammatory response.