according to the fossil record, how long ago do scientists believe life on earth first appeared?

Answers

Answer 1

Answer:

The earliest life forms we know of were microscopic organisms (microbes) that left signals of their presence in rocks about 3.7 billion years old.

Explanation:


Related Questions

materials are cycled out by the chloroplast and mitochondrion​

Answers

Carbon dioxide, Water, Sugar And Oxygen.

Create a new way to purify water

Answers

Answer:

boil

Explanation:

answer: boil it
explainition:make hot water

Where does fertilization of an ovum occur?

Answers

Answer:

a. In the fallopian tubes

Explanation:is correct. post protected

Which vocabulary word could explain an increase in population growth?

A)biodiversity B)island biogeography C)emigration D)immigration

needed asap

Answers

D. ) immigration i think don’t quote me

which specialized structures are unique to the cnidarians?

Answers

Explanation:

Cnidarians contain specialized cells known as cnidocytes (“stinging cells”) containing organelles called nematocysts (stingers).

Cnidarians have stinging cells which are known as cnidocytes. This is the unique feature of cnidarians.

What are cnidarians and their characteristics?

The class Soft-bodied stinging creatures like corals, sea anemones, and jellyfish are categorized as Cnidaria. Nearly every ocean ecosystem contains cnidarians. They may survive in warm or cold, shallow or deep water. Freshwater is home to a few species. Cnidarians can either live alone or in colonies.

Cnidarians share a number of fundamental traits. Cnidaria is all aquatic organisms, primarily marine ones. All of them have stinging tentacles called nematocysts that they utilize to capture prey. Cnidarians have just two body layers: the ectoderm and endoderm, which are divided by a layer that resembles jelly and is known as the mesoglea.

Thus, cnidocytes are unique features of cnidarians.

Learn more about cnidarians, here:

https://brainly.com/question/3606056

#SPJ6

Select the correct pair of classes that are categorized under superclass Pisces.
a) Cyclostomata and Osteichthyes
b) Osteichthyes and Chondrichthyes
c) Agnatha and Gnathostomata
d) Cyclostomata and Chondrichthyes​

Answers

Answer:

d

Explanation:

because it is the answer

8
1 point
If an element is radioactive
0 It will react with other elements to form compounds
It will not react with other elements
It will spontaneously decay into other stable elements
It will spontaneously explode
Previous

Answers

It will spontaneously decay into other stable elements

1. How does Air move in Earth's Atmosphere?

Answers

Answer:

Air in the atmosphere moves around the world in a pattern called global atmospheric circulation. ... When the air cools, it drops back to the ground, flows back towards the Equator, and warm again. The, now, warmed air rises again, and the pattern repeats. This pattern, known as convection, happens on a global scale.

Which of the following is NOT a cause for siblings to look differently?


sexual reproduction


independent assortment


crossing over


mutations

Answers

Answer:

mutations is the answer

What particular organ or component of the body that is involved in regulating PH.

Answers

Answer:kidneys

Explanation:

it filters all liquad

Which items are TRUE about minerals? Select the three correct answers. (2 points)
Observing one property is often the best way to identify minerals,
Rocks are the components that make up minerals.
Minerals can only be identified by their color and hardness.
Minerals are the components that make up rocks.
O Minerals are naturally occurring substances
Minerals are made of one element or one compound of elements

Answers

Answer:

The correct answers are 1) minerals are the components that make up rocks. 2) Minerals can only be identified that make up minerals. 3) Minerals are made of one element or one compound of elements.

Explanation:

I took the test. I got this question wrong but after submitting it, the lesson should me the correct answer.

The items that are true about minerals are:

Minerals are naturally occurring substances.

Minerals are inorganic and homogeneous substances, which can be found on the surface of the Earth, formed in it naturally / spontaneously.

Minerals are made of one element or one compound of elements.

Minerals are found in various forms in nature since they can be of a single element, such as gold, silver, copper, or a combination of elements, such is the case of some chemical compounds such as quartz, which is formed by silicon and oxygen.

Minerals are the components that make up rocks.

A rock is a material that can be made up of a mineral or a combination of them, but its chemical composition is variable.

Therefore, we can conclude that a mineral is a substance produced by processes of inorganic nature which are made of one element or one compound of elements.

Learn more here: https://brainly.com/question/25602434

When protons are actively transported across the cristae membrane in mitochondria to set up a proton gradient between the inter-membrane space and the mitochondrial matrix, this is referred to as___________________

Answers

Answer:

Explanation:

Heres where to get your answer

https://www.info.com/serp?q=website%20medical&segment=info.0546&s1aid=3788024678&s1cid=11804561937&s1agid=114484240723&s1kid=kwd-944088888&utm_source=adwords&gclid=CjwKCAiAm7OMBhAQEiwArvGi3IMQUyr3aRG07nCggQt-8rAAgyPT3rJedCcJxTAl1ve9LJwgIxq21RoC4yQQAvD_BwE

Natural selection, mutation, genetic drift, nonrandom mating, and gene flow are all mechanisms of ______ and can change allele frequencies in populations.

Answers

They are all mechanisms of Evolution and can change allele frequencies in populations

Natural selection, mutation, genetic drift and gene flow are all capable of causing varying changes in allele frequencies in a population. and these changes leads to the violation of Hardy-Weinberg assumptions

Hardy-Weinberg assumption states that; for a population to experience an unchanged allele frequencies, certain conditions must be met by the population such as ; absence of natural, random mating , absence of migration and absence of mutation.

Hence we can conclude that Natural selection , mutation, genetic drift and gene flow are all mechanisms of Evolution and can change allele frequencies in populations

Learn more : https://brainly.com/question/20938537

identify the explanations researchers suggested to explain differences in health and mortality by gender.

Answers

The differences in health and mortality by gender is a phenomenon for which researchers have many possible explanations.

There have been studies that have indicated that there is enough variation in the average health of males and females to conclude that there are factors at play that are affecting health.

Amongst the many possibilities, scientists have mentioned:

Gender-reliant genetic vulnerability Hormonal factorsDifferences in physiology

as the main possible reasons.

Hormones play a big part in the health of each individual and are vastly different between genders, along with the endless differences in physiology at a molecular level. These factors together may explain why some members of a gender are more vulnerable to genetic illness.

To learn more visit:

https://brainly.com/question/5245375?referrer=searchResults

Explain how hydrogen fuel cells work, and why they provide a healthy, clean way to produce heat and electricity. (Site 1).

Answers

Answer:

As there are no moving parts, fuel cells operate silently and with extremely high reliability. Due to their chemistry, fuel cells are very clean. Fuel cells that use pure hydrogen fuel are completely carbon-free, with their only byproducts being electricity, heat, and water.

Answer:

As there are no moving parts, fuel cells operate silently and with extremely high reliability. Due to their chemistry, fuel cells are very clean. Fuel cells that use pure hydrogen fuel are completely carbon-free, with their only byproducts being electricity, heat, and water.

Raul is learning about fetal development, but is confused about the role mitosis plays in the fetus growing. In 3-5 sentences explain what mitosis does in fetal development. Include how the same DNA is in every cell, and how the fetus grows in size.

Answers

Answer:

Most of the fetus will be born in the 40 weeks of pregnancy, but really can accurately only about 5% of babies born in due two weeks in advance or delay two weeks are normal.

Explanation:

the who, the animals, the kinks, and the yardbirds were all part of the __________.

Answers

The Who, The Animals, The Kinks, and The Yardbirds were all part of the BRITISH INVASION. This term is used to indicate the emergence of British (UK) music in the USA.

The British Invasion refers to the cultural phenomenon in which rock and pop music from the UK became popular in the USA.

The British Invasion was not only a musical movement of the mid-1960s, but also included other aspects of British culture.

The Beatles group was a pioneer rock music band that arrived in the USA and was massively popularized.

Learn more in:

https://brainly.com/question/15937878

The functions of which cell structure are described in this list?

Answers

Answer:

Hey!

Wait... which list?

What characteristics do Prokaryotic and Eukaryotic cells share? (Select all that apply)

A. Have DNA
B. Ribosomes
C. Cell Membrane
D. Chloroplasts

Answers

Answer:

Both have:-

A) Have DNA

B) Ribosomes

C) Cell membrane

A decrease in metabolism without a similar, compensatory decrease in alveolar ventilation will have what effect on the systemic pH

Answers

Answer:

The PH will increase

Explanation:

A student is given four components of evolution, shown in the four boxes here. Which statements can be formed using the terminology shown here to accurately describe the evolution within a species? Select ALL that apply.

Answers

Answer:

C and E

Explanation:

The key feature here is that individuals cannot evolve. Individuals are either adapted in their movement. This is how evolution by means of natural selection occurs.

The statements which can be formed using the given terminology are: Individuals have different genetics, leading to the evolution of populations. Individuals with adaptations are based on genetics, allowing for populations to undergo evolution. Thus, the correct options are C and E.

What is Evolution?

Evolution can be referred to as the change in heritable characteristics of biological populations over the period of successive generations. These characteristics are the expressions of genes, which are passed on from the parents to their offspring during the process of reproduction.

The statements which can be formed using the given terminology include: 1. Individuals have different genetics, leading to the evolution of populations. 2. Individuals with adaptations are based on genetics, allowing for populations to undergo evolution

Therefore, the correct options are C and E.

Learn more about Evolution here:

https://brainly.com/question/13492988

#SPJ3

which hormone signals the breakdown of glycogen in the liver increasing glucose in the blood?

Answers

Answer:

The answer is glucagon

Explanation:

When the blood sugar level drops down, the glucagon hormone converts the glycogen into glucose and raises its level in the bloodstream.

Glycogen is a main source of energy for the body. Glycogen is stored in the liver. When the body needs more energy, certain proteins called enzymes break down glycogen into glucose. They send the glucose out into the body.

Which hormone stimulates the breakdown of glycogen in the liver into glucose?

Glucagon's role in the body is to prevent blood glucose levels from dropping too low. To do this, it acts on the liver in several ways: It stimulates the conversion of stored glycogen (stored in the liver) to glucose, which can be released into the bloodstream.

How does glucagon increase blood glucose?

When your blood glucose levels trend lower or fall too low (hypoglycemia), your pancreas releases more glucagon. Glucagon helps blood glucose levels rise back up in multiple ways, including Glucagon triggers your liver to convert stored glucose (glycogen) into a usable form and then release it into your bloodstream.

Learn more about glucose here: https://brainly.com/question/25658352

#SPJ2

are genes for green seeds similar to yellow genes? Explain your answer.

Answers

Answer:

Explanation:

There is no “yellow” gene in the peas found on farms. ... Mendel's experiments showed that green is the recessive seed color in pea plants.

Since yellow is dominant to green, all of the offspring were yellow.


I’ll give brain

Drag the tiles to the correct boxes to complete the pairs.


What is the function of each lymph organ?

The last drop-down box is spleen which you can’t see in the picture.

Answers

Answer: The primary lymphoid organs are the red bone marrow, in which blood and immune cells are produced, and the thymus, where T-lymphocytes mature. The lymph nodes and spleen are the major secondary lymphoid organs; they filter out pathogens and maintain the population of mature lymphocytes

Explanation: hope this helps bye :)

if a cell is in a state in which it no longer divides then the cell is probably arrested at which stage of the cell cycle?

Answers

Answer:

Interphase

I

Explanation:

Interphase is the period of the cell cycle during which the cell is not dividing. The majority of cells are in interphase most of the time. Mitosis is the division of genetic material, during which the cell nucleus breaks down and two new, fully functional, nuclei are formed.

Black fur(B) in guinea pigs is dominant over white fur(b). Find the probability of a white offspring in a cross: Bb x bb. ​

Answers

Answer:

50%

Explanation:

the probability of white offspring is fifty percent

what other type of cell besides plant has a cell wall

Answers

bacteria , fungi and algea

Javier is going to construct a physical model of Earth. What is the correct order, from inside to outside, of earths layer?

A. Crust,mantle,outer core, inner core

D. Lithosphere, asthenosphere, mesosphere, outer core, and inner core

( those are the two choices I ended up with and don’t know which one it is)

Answers

Answer:

Its c

Explanation:

its defo c

why is Ten dollars and Ice not a kinetic energy ?

Answers

Answer: They aren't kinetic energy

Explanation: They are not because it is either motionless or at rest.

In an experiment that compares a combination mental-physical practice condition to an all-mental practice condition, an all-physical practice condition, and a no practice condition, the typical results show that participants in the combination mental-physical practice condition would learn the skill

a. as well as or better than those in the all-physical practice condition.
b. about as well as those in the all-mental practice condition.
c. about as well as those in the no practice condition.
d. The results would depend on the combination of the amount of mental and physical practice.

Answers

The combination mental-physical practice condition is effective to learn the skill as well as or better than those in the all-physical practice condition. Mental-physical practice enhances both cognitive and physical skills.

Mental practice, also known as mental/skill rehearsal, refers to the cognitive (i.e., thinking) rehearsal of a given skill prior to its execution.

It has been shown that mental practice can be effective for enhancing the performance of both cognitive and physical skills.

The mental-physical practice has been shown to be helpful to enhance self-motivation, confidence, and reduce feelings of anxiety.

Mental practices always must be employed to supplement physical practices instead of replacing such physical exercises.

Learn more in:

https://brainly.com/question/14279736

Other Questions
Reescribe cada oracin utilizando los signos de puntuacin necesarios. Recuerda escribir letra mayscula donde corresponda. tengo que comprar presillas grapas sobres y cartulinas A __________-__________ bond is a straight fixed-rate bond issued in one currency that pays coupon interest in that same currency, then at maturity, the principal is repaid in another currency. Multiple Choice warrant-convertible bonds with equity warrants dual-currency exchange-convertible Traditional Chinese culture is the general term for national civilization, customs and spirit. The definition of "culture" is often "the benevolent see benevolence, and the wise see wisdom". Simply put, traditional Chinese culture is based on the three schools of Confucianism, Buddhism and Taoism. The three are interdependent, infiltrate and influence each other, and build the whole of Chinese traditional culture. The ideas of these three traditional cultures are collectively called the "Three Religions" in China. Who is the enemy Oglethorpe is fighting? help please i need help Please Help!!!!!How is the position of the full moon in relation to Earth and the sun different from the position of the full Venus in relation to Earth and the sun? Does the apparent size of the moon change with its phases? Please explain!!!! 100 point giveaway feel free to have some garlic bread aswell Meanwhile, impatient to mount and ride,Booted and spurred, with a heavy strideOn the opposite shore walked Paul Revere.Now he patted his horses side,Now gazed at the landscape far and near,Then, impetuous, stamped the earth,And turned and tightened his saddlegirth;But mostly he watched with eager searchThe belfrytower of the Old North Church,As it rose above the graves on the hill,Lonely and spectral and sombre and still.And lo! as he looks, on the belfrys heightA glimmer, and then a gleam of light!He springs to the saddle, the bridle he turns,But lingers and gazes, till full on his sightA second lamp in the belfry burns! Based on the information marked in the diagram, AMNP and AQRS must becongruent.NRPA. TrueB. False Tianna's Urbanwear advertises the following sale: Shirts are 1/2 off the original price; pants are 1/3 off theoriginal price; and shoes are 1/4 off the original price.A pair of pants usually sells for $33.00. What is the sale price of a pair of pants?Show Your WorkYou have responded to 5 of 8 questions. 1 response is missing a drawingSubmit When carbon dioxide enters the blood, some of it combines with ____________ to form carbaminohemoglobin, but most of it becomes ____________ ions that diffuse into the blood plasma. Why the constitution is bad (X-1)squared Expand and simplify Which of the following describes the Japanese position just prior to the bombing of Hiroshima?A. Japan had steadfastly refused to surrender and continued to expand its territory in Asia.B. Japan had steadfastly refused to surrender and prepared for a direct invasion by the United States.C. Japan had offered to surrender on the condition that it retain various colonies overseas.D. Japan had offered to surrender on the condition that the emperor remains head of state. please help struggling a lot! What is the slope-intercept form and slope and y-intercept of the problem: -4x+2y=10? a tv was sold at 9% profit with cost price rs 18000 calculate the sale price of tv What is a object that produces heat by producing light please? Please help. Thank you! a major advantage of the corporate form of ownership is ______.