about how long ago did the first single-celled life form appear on Earth?

A. 130 million years ago
B. 1.5 billion years ago
C. 2.5 billion years ago
D. 4.1 billion years ago

Answers

Answer 1

Answer:

Around 4.1 billion years ago, the first single celled life form appeared on Earth


Related Questions

Why would a normally aquatic or marine species adapt to the supralittoral fringe where they have to deal with desiccation and temperature stress?​

Answers

Answer:

In order to survive.

Explanation:

A normally aquatic species adapt to the supralittoral fringe in order to survive in that environment. Supralittoral zone also referred to the area on coastlines and estuaries, that is regularly splashed, but not submerged by ocean water. This environment is different for the marine organisms that causes adverse effect on the marine organisms but these marine animals has the ability to adapt that environment by using certain mechanism in order to survive and easily reproduce in that environment.

Explain the three principles of the cell theory​

Answers

Answer:

The three tenets to the cell theory are as described below: All living organisms are composed of one or more cells. The cell is the basic unit of structure and organization in organisms. Cells arise from pre-existing cells.

Explanation:

Can I have brainliest?

Answer:

Answer: 1) All the living organims are compound by one or more cells . 2) The cell is the structural and functional basic unit of life. 3) All cells are originated from other cells.

Explanation: Cell theory describes the characteristics of living organisms and was proposed and refined by many scientists like Schwann and Schleiden. The first principle describes the constitution of living organisms, all of them, unicellular or multicellular are compund by cells. The second principle says that cell is the unit of life in fuctions as metabolism and structural as in tissues. The third principle says that cells can only be generated by division of preexisting cells.

Explanation:

What is the purpose of the part of the male reproductive system that is
highlighted below?
A. Creates the fluid in semen
B. Transfers sperm cells to the urethra
C. Manufactures sperm cells
0
D. Stores sperm cells until they mature

Answers

Answer:

A creates the fluid in semen

please use your own words thank you!

Answers

Answer:

There is a relationship between latitude and temperature around the world, as temperatures are typically warmer approaching the Equator and cooler approaching the Poles.

Explanation:

Latitude and longitude make up the grid system that helps humans identify absolute, or exact, locations on the Earth's surface.

Characteristics of codon

Answers

Yo buddy bro I got a hold for wanna I don’t know how much
Most codons specify an amino acid.

The start codon AUG marks the beginning of a protein.

The stop codon marks the end of a protein.

Which explanation justifies why the theory of evolution is a theory and not a law? (4 points) a The theory of evolution predicts an organism's ability to adapt to its environment. b The theory of evolution can be expressed as a simple mathematical statement. c The theory of evolution explains the existence of diverse forms of life on Earth. d Additional evidence will change the theory of evolution into a law.

Answers

Answer:d.Additional evidence will change the theory of evolution into a law.

Explanation:

HELP ASAP!!!!! Plss sill give u Brainly and heart

Answers

i believe it is A. along the pacific ocean coastlines
It’s is either A. Pacific coastlines or C. Continental areas.

Choose which one you think fits better cause I’m not 100% sure

Mutation is a natural process that changes a DNA sequence. Most DNA changes Faul in a large areas of the genome that sits between genes, and usually they have no effect. When variation occur within jeans, there is more often a consequence, but even then mutations only really cause death or disease. Mutations also generates new variations that can give an individual A survival advantage.

Answers

Answer:

The correct answer is -

1) point mutation

2) deletion

3) inversion

4) frameshift mutation.

Explanation:

Point mutation or substitution mutation is a genetic mutation that takes place when there is a change in a single base nucleotide, it can be replaced with other nucleotides from a DNA or RNA sequence of an organism's genome.

Deletion is a genetic mutation that occurs when there is a loss of a segment of a chromosome. If the particular segment is responsible for an important protein or gene the offspring have to be with one copy only therefore, it is considered a bad mutation.

When there is a reversal of the segment of a chromosome occurs a change takes place in genetic material which is known as the inversion type of genetic mutation.

If any of the above mutations take place including deletion, inversion, replacement or insertion in one or more nucleotides to make a change in the amino acid sequence from the site of mutation forward is frameshift mutation.

The chromosomes are packed together tightly with what in the nucleus of the cell

Answers

Answer:

Chromosones are packed/combined with genetic material/information known as DNA, DeoxyriboNucleic Acid, chromosones are thread-like molecules that carry DNA.

Chromosones are made of protein and one molecule of DNA.

5. Which of these would be the best thing for scientists to examine if they wanted to see if two organisms had a common ancestor?* O They would look at the larval forms of the organisms They would look at what the organisms liked to eat They would look at how the organisms reproduce. O They would look at how the organisms migrated to new locations​

Answers

pretty sure it's "They would look at the larval forms of the organisms".


1. What is the text about?
2. What are the steps presented in this process text?
3. What words help you get the process step by step?
4. What do you think will happen when one or two steps are
missed?​

Answers

Answer:

1. Directions

2

Ride a jeep or tricycle to pass San Juan or Baenotan road.Ask the driver to drop you off at the information officeregister your name as a tourist and coordinate with the trained tourist guide of munieipality of San Gabrielride motorcycle or 'habal=habal' or a jeepneyhave a walk and hike for some hours

3. First, second, third, then

4. Good Luck

Explanation:

how are two identical DNA molecules formed

Answers

Answer:

Explanation:

DNA is a double stranded molecule. When DNA is copied the two strand of DNA (old strands) separate and new nucleotides match up with the two separated strands. This process creates two identical double stranded DNA molecules are formed. Each DNA molecule contains one strand of the original DNA molecule and one newly synthesized (made) strand.

hope it helps :)

Replication occurs in three major steps: the opening of the double helix and separation of the DNA strands, the priming of the template strand, and the assembly of the new DNA segment. During separation, the two strands of the DNA double helix uncoil at a specific location called the origin. Several enzymes and proteins then work together to prepare, or prime, the strands for duplication. Finally, a special enzyme called DNA polymerase organizes the assembly of the new DNA strands. The following description of this three-stage process applies generally to all cells, but specific variations within the process may occur depending on organism and cell type.

How are tropical rain forests and temperate forests different?
A. Temperate forests have more biodiversity.
B. Temperate forests are more productive.
C. Temperate forests are closer to the equator.
D. Temperate forests have more seasonal changes.

Answers

Answer:

d

Explanation:

Tropical rainforests are found closer to the equator where it is warm. Temperate rainforests are found near the cooler coastal areas further north or south of the equator. The tropical rainforest is a hot, moist biome where it rains all year long.

Tropical rain forests and temperate forests are different because temperate forests have more seasonal changes.

How are tropical rain forests different from temperate forests?

Tropical rainforests are found closer to the equator having less seasonal changes while on the other hand, temperate rainforests are found near the cooler regions having more seasonal changes.

So we can conclude that tropical rain forests and temperate forests are differen because temperate forests have more seasonal changes.

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Which of the labeled structures is an adaptation that is primarily responsible for helping a paramecium control its water balance?
Paramecium diagram
A. Structure A
B. Structure B
C. Structure C
D. Structure D

Answers

Structure D , The term "contractile vacuole" refers to this structure. The vacuole gathers extra water from the cytoplasm and contracts to release it. As a result, paramecium doesn't swell and explode in hypotonic liquids.

Why are contractile vacuoles necessary for organisms?

Specialized contractile vacuoles control the amount of water in cells. Its spherical form allows it to gather extra cell fluid and empty it outside. It is essential for preserving the osmotic pressure inside the cell. Protists are eukaryotes with only one cell and are found in wet and aqueous habitats.

The name "contractile vacuole" refers to what?

As its name implies, the contractile vacuole expels water from the cell by contracting. The contractile vacuole periodically expands (collecting water) and contracts (releasing water). Several seconds are required for one cycle, depending on the species .

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Describe the organization of a synovial joint.​

Answers

Answer:

The bones of a synovial joint are surrounded by a synovial capsule, which secretes synovial fluid to lubricate and nourish the joint while acting as a shock absorber. The ends of the joint bones are covered with smooth, glass-like hyaline cartilage which reduces friction during movement.

Explanation:

hope this helps

Select the statement that BEST answers the following question
based on the information provided
Milk is uniformly mixed it contains several compounds-
water, proteins, fats, and sugars. Is milk considered a
substance or a mixture?
It is a liquid substance with uniform composition
b It is a mixture, only solids are pure substances.
С
It is a mixture that can be separated by physical
means
d
It contains compounds and is therefore a
substance

Answers

Answer:

D) It contains compounds and is therefore a substance

Explanation:

A mixture is composed of multiple compounds.

what is Sediment pollution?

Answers

Answer:

sediment is considered when rhere is too much of pollution

2 characteristics that determine water's density

Answers

Answer:

l

Explanation:

In a nucleotide, the nitrogenous base is attached to the sugar at
A. C1
B. C2
C. C3
D. C5

Answers

Answer:

It's A!!!!!!!!!!!!!!!

Consider two genes that are independent, the A gene and the B gene. Each gene has two alleles (A gene: A1 and A2, B gene: B1 and B2). The frequency of A1 allele at the A gene is 0.85 and the frequency of the B2 allele at the B gene is 0.24. What is the probability of an individual in a randomly mating population of having A1B2|A2B1 as their genotype

Answers

Answer:

The probability of an individual in a randomly mating population of having the genotype A1B2|A2B1 = 0.658 = 65.8% ≅ 66%  

Explanation:  

Due to technical problems, you will find the complete explanation in the attached file

The opening and closing of the heart valves is caused by Multiple Choice action potentials within the cusps of the valves. pressure changes of alternating contraction and relaxation during the cardiac cycle. contraction and relaxation of papillary muscles that pull on heart strings. contraction of the smooth muscle in the walls of the great vessels leaving the heart.

Answers

Answer:

pressure changes of alternating contraction and relaxation during the cardiac cycle.

Explanation:

In Human anatomy, cardiac cycle can be defined as a complete heartbeat of the human heart which comprises of sequential alternating contraction and relaxation of the atria and ventricles, therefore causing blood to flow unidirectionally (one direction) throughout the human body.

Generally, the cardiac cycle occurs in two (2) stages;

I. Diastole : in this stage, the ventricles is relaxed and would be filled with blood.

II. Systole: at this stage, the muscles contracts and thus, allow blood to be pushed through the atria.

Hence, the opening and closing of the heart valves is caused by pressure changes of alternating contraction and relaxation during the cardiac cycle.

Why couldn't yeast use both sugar and artificial sweetener for cell respiration?

Answers

Yeast, sugar eating fungus, use oxygen to release the energy from sugar, much like humans, in the process called "respiration". The more sugar there is, the more active the yeast will be and the faster it will grow. Yeast feeds on sucrose, fructose, glucose, and maltose, which it converts to cellular energy through alcoholic fermentation.
Sugar is more suitable for respiration.
The artificial sweeteners are less effective at promoting yeast respiration than sucrose.

Yeast couldn't use both sugar and artificial sweetener for cell respiration because of the low calorie content of artificial sweetener.

What is artificial sweetener?Chemicals called artificial sweetening agents are used to sweeten food. They do not, however, provide our bodies with extra calories.Which one will have better yield?The sugars will have better yield because natural sugars like sucrose have more calories than artificial sugars.This increased energy will allow the yeast to metabolize faster and hence more carbon-dioxide is released.What is cellular respiration?

"Cellular respiration is a series of metabolic processes that take place inside of cells to transform biochemical energy from food into a compound called as adenosine triphosphate (ATP)."

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Problem 1
In dust bunnies, short ears are dominant to long ears. If a heterozygous female mates
with a long ear male, what are the chances their offspring will have short ears?

Answers

Answer:

50% or 1/2

Explanation:

This question involves a single gene coding for ear length in dust bunnies. The allele for short ears (S) are dominant to the allele for long ears (s). This means an heterozygous individual (Ss) will possess short ears.

According to this question, If a heterozygous female (Ss) mates with a long ear male (ss), the parents will produce gametes as follows:

Ss - S and s

ss - s and s

Using these gametes in a punnet square (see attached image), the following proportion of offsprings will be produced:

Ss, Ss, ss, ss

- Ss (1/2 or 50%) offsprings will have short ears.

- ss (1/2 or 50%) offsprings will have long ears.

1. A customer from a previous season comes into your store confused. A
bed of pink four o'clock flowers she planted the previous season self-
seeded and produced a mixture of about 1/4 red, 1/4 white, and 1/2 pink
flowers this year. The customer wants to know why the pink flowers are
now a mix of colors. This is possible because of ...
*

Answers

Answer:

The genes in flowers vary and change every season a little bit if they are not the perfect "pink" or "red" seed gene they will vary.

Hope this helps :)

why spaghetti a heterogeneous mixture?
a.its ingredients cannot distinguish easily
b.its has a main component or base ingredient.
c.its ingredient can be distinguish easily
d.it is delicious and mixed well​

Answers

it is b i think_____________

Imagine you’re a doctor treating a patient with severe vision issues. What questions might you ask to determine whether these issues are more likely to be inherited or caused by environmental factors?

Answers

Answer:

Ask if any of his/her siblings have vision issues

Ask if any of his/her parents or grandparents have vision issues

Ask if any of his/her children have vision issues

Place the following categories from broadest to most specific
Kingdom, Order, Genus, Domain, Species, Class, Family, Phylum

Answers

Domain, Kingdom, phylum, class, order, family, genus, species

Where is ATP produced?

Answers

In plant and animal cells only I believe, hope this helps

I NEED HELP PLS
Chieko is doing an experiment with a water clock. She fills a 2-liter soda bottle with water and marks the water level. She puts two tiny pinholes in the base of the bottle. Water seeps out. She checks the time against her watch. After an hour, she marks the new water level. She repeats this process until the water is all gone. Chieko made six hour marks on the bottle, representing the passage of six hours. How can Chieko test her water clock to see if the timing is accurate?
Group of answer choices

Repeat the experiment using a better watch

Repeat the experiment using less water in the bottle

Repeat the experiment using a kitchen timer set to go off each hour

Repeat the experiment using the same amount of water and the same watch

Answers

Answer: I think the best answer would be C.

Explanation: I think that is correct.

What are the two main sources of energy that power the Earth system?
A. the sun and Earth's interior
B. radioactive decay and volcanic eruptions
C. the sun and the motion of Earth through space
D. the sun and human activities, such as burning fossil fuels

Answers

Answer:

The answer is A, the sun and the Earth's interior.

Answer:

A.the sun and Earth interior

Other Questions
The following symbol () means Which of the lists of letters all have rotational symmetry?C,H, N, XN.O.S. ZH.J.N.SF.H. X. Z *Question 2If a calculator is sold for $15.95, then the revenue in dollars, R, generated by this itemis given by the formula R=15.959, where a represents the number of calculators sold.Use the formula to determine the revenue generated by this item if 40 calculators aresold. Brainlest!!!! 50 PONITS NO LINKS choose the appropriate possessive adjective Las chicas tienen un tio.____ tio es simpaticosusor su Help write step by step:) Which of the following is an example of a learned behavior? *crying babyswimming fishwalkingbreathing PLS HELP, WILL REWARD BRAINLIEST ASAP :) Please help Select the correct answer.A patient is sick from Influenza. What kind of pathogen is this?OA.virusOB.bacteriaO C. fungiOD. helminthesOE.protozoa The weather map shows the weather conditions for one day across the United States. Based on the weather map, what will be the weather like in Texas during the next 24 hours? Which of the following distinguishes why sea ranching is considered more humane than captive forms of aquaculture?because fish are harvested from the oceanbecause it relies on the natural instincts of fishbecause it involves care by aquaculturistsbecause fish can live naturally in the ocean Dude please help I dont understand it Order the events in chronological order Break down the different parts of the World Wide Trade System. Explain why is the trading system important for the free enterprise system. "Hint-hint" (Triangular Trade) PLEASE HELP Which of the following describes how trade between the countries of North America is affected by their geographic location?Select one: a. High taxes make it expensive for these countries to trade with each other. b. It costs much less to transport goods because the countries border each other.c. Moving products is difficult since few rivers flow from the U.S. to other countries.d. Trade is not desired since they are close together and have the same natural resources. Burger Queen a popular fast food restaurant among college students has undertaken a study to determine the weights of the hamburgers served in its new location in San Marcos, TX. Half pounders should weigh at least 8 ounces. The weight is assumed to be normally distributed. A sample of 500 hamburgers reveals the average precooked weight to be 8.02 ounces, with a standard deviation of .4 ounce.1. What is the probability that a hamburger selected at random will weigh between 7.76 and 8.02 ounces? 2. What is the probability that a hamburger selected at random with less than 7.52 ounces? Pls helppp. Is this right? The economic crisis that triggered the French Revolution was caused in part byA) inflation and widespread unemployment.B) inadequate monetary reserves.C) the bourgeoisie's refusal to pay taxes.O D) corruption among local parish priests. what is 20.907x0.0004 Hyperinflations ultimately are the result of excessive growth rates of the money supply; the underlying motive for the excessive money growth rates is frequently a government's: A. desire to increase prices throughout the economy. B. inability to conduct open-market operations. C. need to generate revenue to pay for spending. D. responsibility to increase nominal interest rates by increasing expected inflation.