How did Siberian ancestors arrive in America?

Answers

Answer 1

Answer:

The prevailing theory proposes that people migrated from Eurasia across Beringia, a land bridge that connected Siberia to present-day Alaska during the Last Glacial Period, and then spread southward throughout the Americas over subsequent generations.

Explanation:

hope this helps

Answer 2

Answer:

Explanation:The Beringia land bridge, which had developed between northeastern Siberia and western Alaska due to the lowering of sea level during the Last Glacial Maximum, is generally recognized as the point at which Paleolithic hunter-gatherers reached North America from the North Asian Mammoth steppe.


Related Questions

A person who has a weakened immune system may not be able to fight against infection because
pathogens may enter the body and cause illness.
phagocytes may enter the body and cause illness.
normal cells crowd out unhealthy cells.
antibodies production is increased.

Answers

Answer:

a.

Explanation:

pathogens may enter the body and cause illness.

Immune system is the one that helps to keep away the invading organisms in the body causing disease. A person who has a weakened immune system will not be able to overcome against infection because pathogens may enter the body and cause illness, i.e., option A.

What are pathogens?

Pathogens are the organisms or specifically disease-causing organisms that enter the body and alter the functioning of the immune system.

These pathogens can be bacteria, viruses, etc. that can enter through food, water, air, etc.

A weakened immune system can not be able to fight with these invading pathogens and hence leads to diseases.

Thus, the correct answer is A.

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An old tree near Zion National Park reached the end of its life and fell over. Create a path of a carbon atom as it moves through the carbon cycle. You must start from the dead tree and continue all the way until it ends by being breathed out of a coyote.

Answers

I think it is the ............:

Answer:

There's a reason Zion National Park is the most visited park in Utah, and it's ... But when you make it up (clinging for dear life to the chain handrail), ... If you prefer to keep your feet dry, turn around, and enjoy it all again on the way back. ... This hike starts at the Wildcat Trailhead on Kolob Reservoir Road 15 ...

Explanation:

Which of the following describes a scientific theory, such as evolutionary theory? (Check all that apply).
A. When a scientific theory is proven, it becomes a scientific law.
B. It is an explanation for a wide variety of natural phenomena.
C. It is plausible explanation for many natural phenomena that has not yet been fully tested.
D. Scientific theories are the most certain knowledge that can be developed in science.
E. Numerous studies, which have all tested the theory but in different ways, have all converged on the same explanation.
F. There is ample evidence supporting the explanation.

Answers

Answer:

b

Explanation:

Evolutionary theory highlights the adaptive value of within-species variability. Optimal biological and behavioral strategies differ depending on the nature of the environmental context as well as the characteristics of the organism such as age, sex, health, or physical size.

Fill in the blank.
1. Tall pea plants are dominant, while short plants are recessive. In a cross between a purebred
tall plant and a purebred short plant, the offspring will all be plants.
2. Tall pea plants are dominant, while short plants are recessive. In a cross between two plants
heterozygous for height, the offspring will be both tall and short in a
ratio.

Answers

Answer:

1. The offspring will be all tall pea plants

2. 3:1 is the ratio for tall and short

Answer:

1. tall (or heterozygous)

2. 3:1

Explanation:

Help me please omggggg help meee

Answers

Answer: straight line. Once it hits an object, then it bends.

Hope that helped!

Answer:

im pretty sure its a

Explanation:

Why does the control of blood sugar by insulin show negative feedback?

Select one:

The release of insulin causes sugar levels to increase even more.

Sugar lowers the levels of insulin back to the normal levels.

The release of insulin brings the sugar levels back to normal.

Insulin mixes with the sugar to prevent it from damaging the cells.

Answers

Answer:

The control of blood sugar (glucose) by insulin is a good example of a negative feedback mechanism. When blood sugar rises, receptors in the body sense a change. In turn, the control center (pancreas) secretes insulin into the blood effectively lowering blood sugar levels.

Explanation:

have an good day

Prevailing winds cause ocean currents to move in the same direction as the winds

Claim 1: in all places in the ocean.

Claim 2: in some places in the ocean.

Claim 3: nowhere in the ocean.

Describe evidence that supports the claim you chose.

Answers

Answer:

claim 1

Explanation:

this just has to do with simple energy and momentum conservation as the energy from the wind creates oceanic currents that move in the same direction of the current

Newton's first law of motion

this applies in all places in the ocean

HELP IM TAKING A TEST

Living things have been organized into different categories to make it easier to identify them. Below is a diagram that represents part of the organizational structure of living things. What does the broadest part label X represent?
choices

1.Domain

2.Kingdom

3.Order

4.Species

Answers

Answer:

1. (Domain)From Simple English Wikipedia, the free encyclopedia. In biological taxonomy, a domain (also superregnum, superkingdom, or empire) is a taxon in the highest rank of organisms, higher than a kingdom. Domain (or its synonyms) is the most inclusive of these biological groupings.

What happens when the most
limiting factor in an ecosystem is
removed?

Answers

The answer is A, population growth increases .

—Explanation—
•] The definition of limiting factor; anything that constrains a population's size and slows or stops it from growing.
•]Some examples of limiting factors are biotic, like food, mates, and competition with other organisms for resources.
•] So if the limiting factor is removed then the population begins to expand due to not having a factor that limits each species quantity.

Two radioactive nuclei A and B are present in equal numbers to begin with. Three days later, there are 2.44 times as many A nuclei as there are B nuclei. The half-life of species B is 1.14 days. Find the half-life of species A (in days).

Answers

Answer:

2.23 days

Explanation:

Given that;

N=Noe^-kt

Where;

N= number of radioactive nuclei present at time =t

No= number of radioactive nuclei originally present

k = decay constant

t = time taken

But k = ln2/T

Where T is the half life of the radioactive nuclei

Hence;

NA= Noe^-ln2t/TA     (1)

NB= Noe^-ln2t/TB      (2)

But NA =2.44NB

2.44NB = Noe^-ln2t/TA     (3)

NB= Noe^-ln2t/TB      (4)

Divide  (3) by  (4)

2.44NB/NB = Noe^-ln2t/TA/Noe^-ln2t/TB

2.44 = e^-ln2t/TA + ln2t/TB

Taking natural logarithm of both sides

ln2.44 = -ln2t/TA + ln2t/TB

Given that TB = 1.14 days

TA= -ln2t(ln2.44 -ln2t/TB )^-1

TA= -(2.079) (0.892 - 2.079/1.14)^-1

TA = 2.23 days

What one is true this is due soon.

Answers

Answer:

(B) Genes make up chromosomes.

Explanation:

Your answer is B.

Cells with limited potential to develop into any type of cells are called

Answers

Stem cells
Stem cells

Match the pathway of the carbon cycle

Answers

don’t click the links.

explain how the hydrosphere and atmosphere are related.

Answers

Answer:

Water circulates in a cycle across the hydrosphere. Clouds gather water, which then falls to Earth as rain or snow. Rivers, lakes, and seas store this water. Then it evaporates back into the atmosphere, restarting the loop.

Explanation:

Answer:

The hydrosphere is the part of Earth were all the water is contained.

The atmosphere is the part of Earth were all the gases are contained.

These two are related because the hydrosphere is inside the atmosphere.

The hydrosphere goes down below sea level, because of several trenches and other holes like the Mariana trench. The hydrosphere also goes around 20 kilometres in the air because of clouds.

Help me please!!!!!!!

Answers

Answer:

Decay adds carbon to the atmosphere.

Based on the information in the table above, what Domain name should replace the X?

CHOICES

Archaea

Bacteria

Eukarya

Plantae

Answers

The answer to the question is Eukarya

Normally, the clown fish readily swims among the tentacles of the sea anemones; the parrot fish avoids them. One hypothesis for the clown fish's apparent immunity is that they slowly build a tolerance to the sea anemone's toxin. A second hypothesis is that a chemical in the mucus that coats the clown fish prevents the nematocysts from being triggered.

Required:
Draw the graphs that supports the first, but not the second, of these hypotheses.

Answers

Answer:

The correct answer is - parrot fish - high, Clown fish - high.

Explanation:

According to the first hypothesis, the clown fish developed the immunity to the sea anemone's toxin so there would be a higher number of clown fish that swims among the tentacles of the sea anemones. The parrot fish avoids them also leads to a higher number of these fishes.

The correct graph that supports the first hypothesis that says that the clown fish's developed immunity build by them slowly, a tolerance to the sea anemone's toxin from tentacles of sea anemones.

Plants and insects store their sugar in the form of

Answers

Plants and insects store their sugar in form of starch.

After reading the paragraph for Practice 5, what are the possible risks and drawbacks of this use of genetic engineering?

Answers

Answer:

Genetic contamination,  competition with natural species, creating potential for problematic pathogens,  unwanted side effects and  unfavorable level of diversity.

Explanation:

The possible risks and drawbacks of the use of genetic engineering are genetic contamination,  competition with natural species, creating potential for problematic pathogens,  unwanted side effects and  unfavorable level of diversity. These drawbacks puts pressure on the native species and due to competition with natural species, removal of natural species occurs. There are many side effects of genetic engineering species on the health and ecosystem.

Please help this is a 7th grade science problem

Answers

Answer:

The Answer is C

Explanation:

Mark me as Brainliest PLEASE

Answer is...

Molecule B

Which of the following statements is true? The spongy layer doesn't have any chlorophyll. The epidermis is the main location for photosynthesis. The cuticle slows down the loss of water in a leaf. Plants can make food without chlorophyll. PLEASE HELP ​

Answers

Answer: the cuticle slows down the rate of water loss.

Explanation: the spongy layer contains chlorophyll although few. Photosynthesis occurs in the chloroplast.

Plants need chlorophyll because it captures sunlight which helps in the splitting of water molecule during photosynthesis ,thus they need it to manufacture their food.

3 weeks late :')

----------------------

the dude above me is right <3

Bases in DNA are held together by which bond?

Answers

Answer:

The two strands are held together by hydrogen bonds between the bases, with adenine forming a base pair with thymine, and cytosine forming a base pair with guanine.

Explanation: hydrogen bonds

Interconnected food chains are also known as​

Answers

Answer:

I think it is food web............

A food web which shows the energy flow through part of an ecosystem.

what do you think life is like on other planets ? 3-5 sentences

Answers

Answer:

Both plants and animals require water for survival. Planet Earth is very special because it contains so much water in liquid form. We have yet to find a planet with the same amount of liquid water as on earth but there are many new “exoplanets” being discovered orbiting other stars that offer this possibility

Explanation:

and aliens

Please Drag the correct moon phase name to its correct location

Answers

Answer:

The correct answer is -

1. First Quarter Moon, 2. Waxing Gibbous Moon, 3. Full Moon, 4. Waning Gibbous Moon, 5. Third Quarter Moon, 6. Waning Crescent.

Explanation:

The lunar cycle goes through eight different phases during the time period of 29.53 days while revolving around the earth. These phases move from new moon to full moon and then full moon to again new moon. The four major phases are New moon phase, the first quarter phase, the full moon, and the third or last quarter phase.

In this diagram, there are 1. First Quarter Moon, 2. Waxing Gibbous Moon, 3. Full Moon, 4. Waning Gibbous Moon, 5. Third Quarter Moon, 6. Waning Crescent. in order occurs.

What happens to a rock when it is exposed to water for long periods of time?
1)the rock becomes more angular
2)the rock changes composition
3)the rock becomes round and smooth

Answers

HINT: The rock will erode

The table shows data about abiotic factors of streams in two different watersheds.
In general, a stream with a lower temperature and more neutral pH tends to be healthier. Based on these
criteria, which watershed contains the healthier stream?
Select one:

Watershed 2

Both streams are equally healthy.

There is not enough data provided to answer the question.

Watershed 1

Answers

Answer: b

Explanation:

Based on these criteria, the watershed that contains the healthier stream is, that both streams are equally healthy. The correct option is B.

What are abiotic factors?

An abiotic factor is a non-living component of an ecosystem that influences its surroundings. Temperature, light, and water are all components of the terrestrial environment.

Abiotic elements in a marine ecosystem include salinity and ocean currents. Abiotic and biotic forces interact to form a distinct ecosystem. Abiotic influences are found in all non-living components of an ecosystem.

They are often made up of both physical and chemical components. Abiotic factors are nonliving components of an ecosystem that influence the environment. Temperature, light, and water are among the examples. Abiotic elements in a marine ecosystem include salinity and ocean currents.

Therefore, the correct option is B. Both streams are equally healthy.

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Which country is heavily dependent on tourism for its livelihood?
А.
United States
В.
China
C. Dubai
D.
Peru
E. Japan

Answers

Answer: В.

China

Explanation:

Which correctly describes a difference between the male and female
reproductive systems?
O A. Males store gametes in the ovary.
B. Females produce fewer gametes.
C. Females produce gametes every day.
D. Males receive gametes from females.

Answers

Answer:

B . Females produce fewer gametes.

Explanation:

The option that correctly describes a difference between the male and female reproductive systems is B. Females produce fewer gametes.

What is a reproductive system?

The reproductive system is a collection of organs and tissues that work together to produce, transport, and fertilize gametes (sperm in males and eggs in females) to facilitate reproduction. In males, the reproductive system includes the testes, epididymis, vas deferens, seminal vesicles, prostate gland, and urethra.

Sperm are produced in the testes, mature and are stored in the epididymis, and then transported through the vas deferens and mixed with seminal fluid produced by the seminal vesicles and prostate gland before being ejaculated through the urethra during sexual intercourse. In females, the reproductive system includes the ovaries, fallopian tubes, uterus, cervix, and vagina.

Eggs are produced in the ovaries and are transported through the fallopian tubes, where fertilization can occur. The fertilized egg then implants in the uterus, where it can develop into a fetus. Hormones, such as estrogen and testosterone, play important roles in regulating the reproductive system and maintaining sexual characteristics.

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The light reactions of photosynthesis occur when light energy is absorbed by the chloroplasts of cells of photosynthetic organisms
Which of the following is produced during the light reactions?

A.chemical energy in the form of ATP and NADPH
ОВ.
B.Carbón dioxide
C.chemical energy in the form of glucose
D.light

Answers

Answer:

A

Explanation:

G o o g l e

Chemical energy in the form of ATP and NADPH

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