What evidence BEST supports the presence of atmospheric oxygen 2.7 billion years ago?
a. carbon 14 in plants
b. fossils found in stomatolites
c. layered iron rust in rocks

Answers

Answer 1

Answer:c

Explanation:layered iron rust in rocks


Related Questions

Large molecules that are built from repeating smaller molecules called
(Insert first answer) are called (insert second answer)

Answers

Answer:

The first answer would be a polymer and the second answer would be a monomer.

The answer to this message would you like you

Which land biome would have a smaller plant and animal population because of its colder climate?

Answers

Answer:

A. Tundra

Explanation:

Think Antarctica. That's a Tundra.

Answer:

Tundra

Explanation:

describe the three general methods used by ecologists to study organisms

Answers

Answer: The three main research methods used are observation, modeling, and experimentation.

Explanation:

Observation:

Every experiment requires observation. Ecologists must observe the environment, the species within it, and how those species interact, grow and change. Different research projects different types of assessments and observations.

Ecologists sometimes use a desk-based assessment, or DBA, to collect and summarize information about specific areas of interest. In this scenario, ecologists are using information already collected from other sources.

Oftentimes, however, ecologists rely on observation and fieldwork. This entails going into the habitat of the subject of interest to observe it in its natural state. By doing field surveys, ecologists can track the population growth of species, observe community ecology in action and study the impact of any new species or other introduced phenomena in the environment.

Each field site will differ in nature, shape, or other ways. Ecological methods allow for such differences so that different tools can be used for observations and sampling. It is crucial that sampling be done randomly to combat bias.

Modeling:

Ecological methods rely heavily on statistical and mathematical models. These provide ecologists with a way to predict how an ecosystem will change over time and react to changing conditions in a system.

Modeling also provides another way to decipher ecological information when fieldwork is not practical. There are several drawbacks to relying solely on fieldwork. Because of the typically large scale of fieldwork, it is not possible to replicate experiments exactly. Sometimes even the lifespan of organisms is a rate-limiting factor for fieldwork. Other challenges include time, labor, and space.

Modeling provides a method in which to streamline information more efficiently.

Examples of modeling include equations, simulations, graphs, and statistical analyses. Ecologists use modeling for producing helpful maps as well. Modeling allows for calculations of data to fill in gaps from sampling. Without modeling, ecologists would be hampered by the sheer amount of data that needs to be analyzed and communicated. Computer modeling allows for comparatively rapid analysis of data.

A simulation model, for example, enables the description of systems that would otherwise be extremely difficult and too complex for traditional calculus. Modeling allows scientists to study coexistence, population dynamics, and many other aspects of ecology. Modeling can help predict patterns for crucial planning purposes, such as for climate change.

Humanity’s impact on the environment will continue. It, therefore, becomes ever more crucial for ecologists to use ecological research methods to find ways to mitigate the effects on the environment.

Experimentation:

The overarching purpose of ecological methods for research is to get high-quality data. Experiments must be carefully planned.

Hypothesis: The first step in any experimental design is to come up with a hypothesis or scientific question. Then, researchers can come up with a detailed plan.

Factors that affect fieldwork experiments include the size and shape of an area that needs to be sampled. Field site sizes range from small to very large, depending on what ecological communities are being studied. Experiments in animal ecology must take into account the potential movement and size of animals.

For example, spiders would not require a large field site for study. The same would be true when studying soil chemistry or soil invertebrates. You could use a size of 15 meters by 15 meters.

Herbaceous plants and small mammals might require field sites of up to 30 square meters. Trees and birds might need a couple of hectares. If you are studying large, mobile animals, such as deer or bears, this could mean needing a quite large area of several hectares.

Deciding upon the number of sites is also crucial. Some field studies might require only one site. But if two or more habitats are included in the study, two or more field sites are necessary.

Tools: Tools used for field sites include transects, sampling plots, plotless sampling, the point method, the transect-intercept method, and the point-quarter method. The goal is to get unbiased samples of a high-enough quantity that statistical analyses will be sounder. Recording information on field data sheets aids in the data collection.

A well-designed ecological experiment will have a clear statement of purpose or question. Researchers should take extraordinary care to remove bias by providing both replication and randomization. Knowledge of the species being studied as well as the organisms within them is paramount.

Results: Upon completion, collected ecological data should be analyzed with a computer. There are three types of ecological experiments that can be made: manipulative, natural, and observational.

Hope This Helps!

The 3 general methods used by ecologists to study organisms include:

ObservationModellingExperimentation

Observation involves observing organisms in their natural habitats or environments and then recording the findings. It is usually done by field surveying.

The different species living in an environment, how they interact with each other and other abiotic components of the environment are some of the observations taking during field surveys. The growth of individual species, the effects of introducing new species, their adaptations and other areas of community or ecosystem ecology can be studied through observation.

Modelling requires a simulation of real-life ecological processes through  different manipulations. This could be done in the laboratory, on the field, or even on the computer. Computer modelling requires that data from observation or experimentation are supplied as input and the inputs are subject to mathematical maneuvering.

With models, complex ecological processes can be simulated and analyzed and extrapolated to deduce how things might happen in real life ecological interactions.  

Experimentation involves setting up experiments following the scientific method. It can be a observational or controlled experiments.

Observational experiments requires studying organisms, populations, communities, or ecosystems through pure observation without changing or manipulating any variable.

Controlled experiments requires that variables are introduced and manipulated in some groups while some groups serve as the baseline without any manipulated variables.

Data are obtained from experiments and these are analyzed in relevant ways to support or reject hypotheses.  

More on ecological studies can be found here: https://brainly.com/question/22875048

Fiona wants to use the scientific method to answer the question “Do oxygen levels in the air affect rates of photosynthesis?” She reads about photosynthesis in her biology book and is ready to carry out the next step. What should she do next?
perform an experiment
design a procedure
make observations
form a hypothesis

Answers

The first thing Fiona, or anyone, should do is form her hypothesis.

The hypothesis is your own proposed explanation for whatever phenomenon you're trying to study. Think of it as a predetermined idea of what could happen based on what you already know.

Answer:

The correct answer is D!:)

Explanation:

Hope this helps!:)

36. In this Phylogenetic tree the newest evolutionary branch is between
(1 point)
dinosaurs and birds
O dinosaurs and frogs
O humans and sharks
O humans and whales

Answers

I thinks it’s human and sharks of humans and whales

Drag the tiles to the correct boxes to complete the pairs.
Match the characteristics with the phylum.
water vascular system
tentacles with stinging cells
molting for growth
the presence of mantle
Arthropoda
Cnidaria
Molluska
Echinodermata

Answers

Answer:

Water vascular system = Echinodermata

Tentacles with stinging cells= Cnidaria

Molting for growth= Arthropoda

Presence of mantle= Molluska

Explanation:

How does a bacterium compare to a frog at the cellular level?

Answers

Answer:

Bacterium is prokaryotic while frog is eukaryotic, also Bacterium is unicellular while frog is multicellular

Explanation:

Bacteria can be considered unicellular prokaryotic organisms, whereas a frog is a multicellular eukaryotic organism.

What are prokaryotic cells?

Prokaryotic cells are specific cells that do not have a cell nucleus and also lack membrane-bound organelles.

Conversely, eukaryotic cells contain organelles and the genetic material is compartmentalized in the nucleus.

In conclusion, bacteria are unicellular prokaryotic organisms, whereas a frog is a multicellular eukaryotic organism.

Learn more about prokaryotic cells here:

https://brainly.com/question/5716507

#SPJ2

I’ll mark u as brainliest! Tell me what definition goes where ?!

Answers

1. Two traits blend...
2.Two traits are both....
3. Determined by...

Answer:

Codominance- Two traits are both present in a third phenotype.

Incomplete Dominance- Two traits blend to form a third phenotype.

Sex-Linked Traits- Determined by gene located on sex chromosomes.

Explanation:

I hope this helps.

Why does sound not literally blow us away?

Answers

Answer:

i.d.k what?

Explanation:

Which of these biological communities has permafrost? A. Tundra B. Grassland C. Desert D Forest​

Answers

Answer:

the tundra biome :)

Explanation:

grass lands aren't very cold

forests aren't cold

the desert is hot

and tundra is super cold

A. Da tUnDrA c;
ur welcome

Ehlers-Danlos syndrome is a genetic disorder that weakens the binding properties of connective tissues. What would most likely be one of the symptoms of this disorder?
A.
Increased joint mobility
B.
Decreased brain activity
C.
Decreased bone density
D.
Increased muscle size

Answers

Answer:

Increased Joint Mobility

HELP ASAP PLZ PLZ


Would the crater size for an impact crater change if it was dropped from 6 meters (18 ft)? Why or why not?

Answers

Answer:

yes it would change

Explanation:

lots of factors can contribute like acceleration distance and resistance.

4. In a prairie ecosystem, nitrogen and other matter builds up in animal
wastes. Which organisms return this matter to the ecosystem by
breaking down wastes?

Answers

Answer:

Fungi, insects, and earthworms

Explanation:

They decompose wastes, returning nitrogen back to the ecosystem.

21. All the following are differences between arteries and veins
except
arteries are thick and veins are thin
O arteries do not have valves and veins have valves
arteries connect to capillaries and veins do not connect to capillaries
arteries carry blood away from the heart and veins carry blood back to the heart
22. All the following are the 3 major parts of the cardiovascular system
VA

Answers

Answer:

Arteries connect to capillaries and veins don't connect to capillaries

Explanation:

Actually both are connected by capillaries

How do I know how much energy is availably in each level of the energy pyramid?

Answers

Answer:

What Exactly Do Energy Pyramids Have to Do With Energy? Energy pyramids show a very cool trend: Each level only gets 10% of the energy from the level below it.

Explanation:

Bats and birds eating insects at different times of day is an example of (1 point)
O survival of the fittest.
O resource partitioning.
O competitive exclusion.
O natural selection.

Answers

Bats and birds eating insects at different times of day is an example of Resource Partitioning. So, the correct option is B.

What is Resource Partitioning?

Resource partitioning or niche differentiation is a process of natural selection that will force competitors to use resources differently in such a way as to avoid competition between species. Resource partitioning causes the co-existence of species.

If bats and birds eat insects at different times of the day, there is no survival of the fittest. Competitive exclusion states that no two species can co-exist in the same niche for a long time.  

Therefore, bats and birds eating insects at different times of day is an example of Resource Partitioning.

To learn more about Resource Partitioning, refer to the link :

https://brainly.com/question/15686970

Which is the best way of comparing two or more organisms
A. Homologous structures
B. DNA
C. Vestigial Structures
D. Fossils

Answers

Answer:

its b

Explanation:

the effects of toxic chemicals are minimized by which following three mechanisms

Answers

Answer:

Metabolic degradation, excretion, and repair.

Explanation:

Move this lichen
to where it belongs within the process of primary succession


Pls help 15 points

Answers

Answer:

1

Explanation:

Lichen are usually the first thing to grow on bare rock, making them a pioneer species. Fun fact, you can use lichen to determine if the air quality in an ecosystem is polluted.

Hope this helped :)

Henry is a forensic scientist who works in the lab. He has to process evidence that was collected by the field officer. Henry knows that the field officer believes the perpetrator was the victim’s best friend, and has collected evidence to prove such. Which two types of bias affect this investigation? Henry believes that bias might be present, because the field officer selectively collected evidence. He also believes that is present, because the field officer has come to a conclusion before the evidence is processed.

Answers

1st- Selection bias, 2nd - expectation bias

Wow I feel like such a hero

Plasma estrogen levels reach their peak at the end of the luteal phase of the ovarian cycle.

a. True
b. False

Answers

Answer:

Plasma estrogen levels reach their peak at the end of the luteal phase of the ovarian cycle.

a. True

Explanation:

A woman's estrogen levels become highest towards the end of her ovulation.  At this point, the woman is naturally prepared for a possible pregnancy.  The occurrence of the highest estrogen levels coincides with the luteal phase, a stage of a woman's menstrual cycle, which occurs after ovulation (or the release of eggs from the ovaries), and before the start of the normal period. This luteal phase has been observed to be within 14 days for all women.  By the end of the luteal phase, the corpus luteum function declines.

Why do plant cells need a cell wall and chloroplasts but animal cells do not?

Answers

Answer:

Plant cell needs cell wall whereas animal cell do not because the plants need rigid structure so that they can grow up and out . ... So animal cells can have various shapes, but plant cells only have the shapes of their cell walls.

Explanation:

Thats because Plant cell needs cell wall whereas animal cell do not because the plants need rigid structure so that they can grow up and out . ... So animal cells can have various shapes, but plant cells only have the shapes of their cell walls.

Which of these does not provide information about the geologic history of Earth?

A) fossils


B) ash from volcanoes


C) debris from meteorites


D) current weather patterns

Answers

Answer:

is B

Explanation:

volcanic activity was more common in the past than it is today.

The picture below shows the bone structures of whale and bird.

Picture shows similar bone structures of whale and bird.

Based on the diagram, which of these statements is correct about whales and birds? (2 points)

Group of answer choices

They use their limbs to catch their prey.

They move in the same manner.

They have similar food habits.

Answers

I had almost the same question on one of my quizzes but it had one other answer. Mine was,

"The picture below shows the bone structures of whale and bird.

Picture shows similar bone structures of whale and bird.

Based on the diagram, which of these statements is correct about whales and birds?  

 a ) They have similar food habits.

b ) They move in the same manner.

c ) They share a common ancestor.

d ) They use their limbs to catch their prey."

After doing some research, I found that the correct answer was that they share a common ancestor.

if micocondrea is the powerhouse of the cell how do i do taxes

Answers

Answer:

(;-;)

Explanation:

To be honest i dont know either

14. Scientists use models of earthquakes to (5 points)
O change their location
O stop them from occurring
O understand the process
O increase the waves formed in the process

Answers

Stop them from occurring

Answer:

under stand the process

Explanation:

i took the test

goodluck to people taking it

which of tge following is true about Earth's temperatures?​

Answers

Answer:

Water vapor and clouds are the major contributors to Earth's greenhouse effect

Explanation:

what's the importance of microscope in the study of animal ​

Answers

It can examine cells and structures not visible to the human eye. Possibly discover parasites

Answer:

It is important because biology mainly deals with the study of cells, genes, and all organisms. Some organisms are so small that they can only be seen by using very strong magnifications, which can only be achieved by a microscope.

Chomosomes are duplicated during

Answers

Answer:

Chomosomes are duplicated during interphase

Brainliest?

Chromosomes are duplicated during the S phase of interphase.

Question 17
Identify the organelle by its function
Creates ATP (energy) and known as the powerhouse of the cell.

Answers

the organelle is called the mitochondria
Mitochondria, it’s known as the powerhouse of the cell
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