where do we find high nutrient availability for photosynthesis? the tropics with a strong thermocline, iron rich sediments of the bathyal zones, surface zones of weaker thermoclines/stratification, near the surface at the centers of gyres

Answers

Answer 1

The places where we will get high nutrient availability for photosynthesis are the surface zones of weaker thermoclines. So, the third option is the best option.  

Gyres are remote areas that are not suitable for photosynthesis at all. Phytoplanktons that fix most of the Earth's oxygen through photosynthesis are scarce in such regions as well.  Bathyal zones are also not good for photosynthesis since no light really reaches these spots. They are really deep and dark, which means no sunlight for plants.

Areas with a strong thermocline are no good because they prevent the mixing of nutrients in the water. This means that regions of weak thermocline are what suit nutrient availability the best.

Learn to know more about Photosynthesis on

https://brainly.com/question/1757345?referrer=searchResults

#SPJ4


Related Questions

Why is photosynthesis and cellular respiration considered a cycle?

Answers

Answer:

Cellular respiration and photosynthesis are considered a cycle because the product (end material) of one reaction serves as the starting material for the other reaction

Explanation:

The starting material for cellular respiration is sugar and water and the products are carbon dioxide and water. Water and carbon dioxide are starting material for photosynthesis.

Please give me Brainly.

All the best.

Sky(✿◡‿◡)

which of the following would be the first step in biosynthesis of a virus with a - (minus) strand of rna?
a. synthesis of protein from - strand RNA used as a template
b. synthesis of DNA from - strand RNA used as a template
c. synthesis of + stranded RNA from - strand RNA used as a template
d. synthesis of - stranded RNA from - strand RNA used as a template

Answers

Answer: Synthesis of double-strand RNA from an RNA template.

Explanation:

What defines a substantial increase in a jellyfish population within a short time?.

Answers

As a result of a greater reproductive rate, a jellyfish bloom is described as a significant rise in a jellyfish bloom within a short period of time.

What drives the growth in the number of jellyfish?

Because jellyfish can survive with less oxygen than many other marine animals, the rise in their population has been linked to hotter waters and even increasing pollution.

What does it signify when there are many jellyfish present?

The recent period of sunny skies and southerly winds may have increased the amount of nutrients in the water, enhancing the conditions for jellyfish repopulation. One aspect that contributes to enormous jellyfish spawning like those is eutrophication, which is the scientific word for an overabundance of nutrients.

To know more about jellyfish bloom visit:-

https://brainly.com/question/11598697

#SPJ4

In an experiment, you test whether the number of times you rub a cloth against a balloon changes how long it will stick against the wall. You start by rubbing the balloon 10 times with the cloth and stick it to the wall. You repeat this three times and record your results in a table.


Observation
Number of Times Balloon is Rubbed by Cloth Trial #1 Trial #2 Trial #3
10 6 seconds 20 seconds 20 seconds


What statement best reflects why you should do repeated trials in an experiment?
Rubbing the balloon against a cloth 10 times produces very different results each time it is repeated.
The first trial is right because it is done with new materials that give the best results.
The second and third trials were wrong because they were very different from the first trial.
You would make a wrong conclusion if it were based on the first trial in the experiment.

Answers

The statement that best reflects why you should do repeated trials in an experiment is:

You would make a wrong conclusion if it were based on the first trial in the experiment; option D.

What are experiments?

Experiments are tests or procedures performed to test a given hypothesis or theory about a given observation.

In performing experiments, the procedure usually involves the repetition of steps in the reaction.

Repetition is necessary in order to remove bias in measurements and to lower sampling and random error.

The steps in conducting experiments include the following:

stating the research questionstating the aim of the experimenetmaterial and methodsresults ad discussionconclusion

Learn more about experiments at: https://brainly.com/question/25303029

#SPJ1

A life cycle in which the only multicellular form is haploid is most typical of __________.

Answers

A life cycle in which the only multicellular form is haploid is most typical of fungi.

In the lifecycle process of fungi, the haploid stage of lifecycle is known to be multicellular and it is te dominant stage.

As a result of the haploid multicellular stage, specialized cells that are also haploid are made.

The process through which these haploid cells will be made is mitosis as for meiosis sexual process has to take place.

After mitosis, the specialized haploid cells that were produced are fused so that a diploid zygote can be formed which will grow into a new fungus.

To learn more about fungi, click here:

https://brainly.com/question/13050764

#SPJ4

The ability to produce language is a function of _________, whereas the ability to understand language is a function of _________.

Answers

The ability to produce language is a function of Broca's area, whereas the ability to understand language is a function of Wernicke's area.

What distinguishes Wernicke's territory from Broca's area?

In essence, Wernicke's area strives to ensure that the language makes sense, but Broca's area attempts to guarantee that the language is produced in a fluent manner. The Wernicke-Geschwind model, which was later suggested by neurologist Norman Geschwind, built on this understanding of language.

Broca's area is situated in the neocortex's posterior-inferior frontal convexity, whereas Wernicke's area is restricted to the general region where the parietal, occipital, and temporal lobes converge. For the majority of people, the left hemisphere is where these areas function predominantly in terms of language.

To know more about Broca's area visit:

https://brainly.com/question/29412751

#SPJ4

a farmer performs a cross between two species of flowers and expects a distribution of red, pink, and white flowers. out of flowers, the following numbers of red, pink, and white flowers were observed. calculate the expected number of each type of flower.

Answers

Due of the flowers' inability to consistently produce the necessary 1:2:1 ratio of bloom colors, the farmer will be unable to meet demand. There are 250, 500, and 250.

A common flower is what?

The most widespread and well-liked flower genus in the world is undoubtedly the rose. There are over least 360 species of flowers in the Rosa genus, which includes these blooms. These blooms naturally occur in a variety of hues, including red, pink, apricot, and white.

What kind of flower is lovely?

Rose. The rose is known as the "queen of the garden" since it is thought to be the most flower petal in the entire world. It is one of most well-liked flowers on the planet and is available in a variety of hues and sizes. They are also widely distributed around the world.

To know more about farmer visit:

https://brainly.com/question/15589170

#SPJ4

Iconic maine species such as moose, canada lynx, loons, boreal chickadees, eastern brook trout, saltmarsh sparrows and atlantic puffins are under stress from climate change. A mutation in the boreal chickadees increases the ability of the bird to catch and eat certain insects. Which factor might determine whether the frequency of the new allele will increase?.

Answers

The frequency of the new allele may be determined by whether the mutation offers the chickadees better access to food sources than those without it.

Mutation:

A mutation is a permanent change in the genetic material (the genome) of a cell of a live creature or of a virus that may be passed on to the cell's or virus's progeny. (Organic genomes are all made of DNA, although viral genomes can be made of either DNA or RNA; see heredity. The Physical Basis of Heredity.) A mutation in the DNA of a body cell of a multicellular organism (somatic mutation) can be passed on to descendant cells via DNA replication, resulting in a sector or patch of cells with abnormal function, such as cancer.

Mutations occur as a result of errors during the regular chemical transactions of DNA, most commonly during replication, or as a result of exposure to high-energy electromagnetic radiation (e.g., ultraviolet light or X-rays), particle radiation, or highly reactive substances in the environment. Mutations are believed to be largely harmful since they are random alterations, although some may be advantageous in specific settings. In general, the mutation is the primary source of genetic variation, which serves as the raw material for natural selection evolution.

To know more about mutation visit the link:

https://brainly.com/question/17031191

#SPJ4

sustainable development must be considered during the developmental activities justify this statement​

Answers

Sustainable development has been defined as development that meets the needs of the present without compromising the ability of future generations to meet their own needs

Hope this helps:)

one kind of plasmid in bacteria is called an r plasmid. what kinds of genes are typically present on such plasmids?

Answers

One type of bacterial plasmid is called an r-plasmid. Types of genes typically present in such plasmids Antibiotic resistance genes

Antibiotic resistance genes are often carried in plasmids or transposons and are transferred from cell to cell by conjugation, transformation, or transduction. This gene exchange allows rapid spread of resistance within bacterial populations and between different bacterial species. Some genetically modified plants contain genes that make the plant resistant to certain antibiotics. Scientists often then and can say that add these resistance genes during genetic modification. This allows GM plants and cells to be distinguished from non-GM plants and cells.

To know more about Antibiotic resistance genes visit:

https://brainly.com/question/29412753

#SPJ4

Please help me
It’s due

Answers

The effect of shortage of the following factors on the rate of photosynthesis is given below:

CARBON DIOXIDE (CO₂) - Slows down photosynthesisOXYGEN (O₂) - No changeGLUCOSE (C₆H₁₂O₆) - No changeSUNLIGHT - Slows down photosynthesisWATER (H₂O) - Slows down photosynthesis

What is photosynthesis?

Photosynthesis is the process by which plants produce food from carbon dioxide and water using the energy of sunlight.

The rate of photosynthesis is affected by the following:

amount of sunlight - the greater the amount of sunlight, the faster the rate of photosynthesisamount of carbon dioxide - the greater the amount of carbon dioxide, the faster the rate of photosynthesisamount of water vapor in the atmosphere - the greater the amount of water vapor, the faster the rate of photosynthesis

Learn more about the rate of photosynthesis at: https://brainly.com/question/2114560

#SPJ1

Which of the following best describes the genetic material a person receives from each parent?

Answers

I'm pretty sure an x or y chromosome

Explain your understanding of a calorie, how energy is stored in the body and what factors make our individual energy requirements so unique. A portion of our consumed energy goes towards physical activity each day. Share some of the daily activities you perform that you think would require this energy.

Answers

Calorie, a unit of energy, is the amount of energy expelled when the body breaks down food, it is stored in the body as glycogen or fat and gender, body weight, and age make individual energy requirements unique.

Some daily activities that require physical energy are Riding a bicycle, walking fast, hiking, skating. dancing, workouts.

How are calories burned?

Calories are energy people get from foods and drink they consume. Apart from basic metabolism, the way the body uses food determines how much calories the body burns.

The body stores this energy as glycogen or fat. Body weight, age and gender are determinants of the body's use of energy. Energy requiring activities include workouts, dancing, hiking etc., to burn calories.

Learn more on calories here: https://brainly.com/question/11460467

#SPJ1

Which of the following compounds can be classified as a proteins?

Answers

Where’s the picture?

what is microbial antagonism?

Answers

Microbial antagonism is the competition between microbial organisms for food assets and territory. As a result, if one organism out competes the other, this leads to the inhibition of the organism that failed to thrive in the surroundings.

Microbial antagonists have an indirect advantageous effect on plant life due to the fact they lessen the pressure from soil borne pathogens on the crop vegetation. however there is also a brilliant quantity of microorganisms inside the soil, that have a right away high-quality impact on plant increase and health (Somers et al., 2004).

Microbial antagonism continues ordinary microbiota from colonizing a few parts of the human body. Microbial antagonism takes place whilst members of the regular microbiota prevent pathogens from colonizing and turning into mounted within the frame.

Antagonism, in ecology, an affiliation among organisms in which one benefits at the expense of the opposite. As existence has evolved, herbal choice has favoured organisms which can be capable of correctly extract electricity and nutrients from their surroundings.

Learn more about Microbial antagonism  here:

https://brainly.com/question/28149629

#SPJ4

Which of the following is a basic type of vaccine?
Select all that apply.
a. nucleic acid vaccines
b. subunit vaccine
c. live, attenuated vaccine
d. antitoxin vaccines

Answers

The basic type of vaccines are:

nucleic acid vaccines

subunit vaccine

live, attenuated vaccine

An easy, secure, and reliable method of preventing hazardous infections before you are exposed to them is vaccination. It boosts your immune system and builds up your body's natural defenses against particular illnesses.

Your immune system is trained by vaccinations to produce antibodies, exactly as it does when it is exposed to a disease. However, because vaccinations only include dead or weakened versions of bacteria or viruses, they do not really cause the disease or increase your chance of developing its symptoms.

In order to create immunity, vaccines act in conjunction with your body's natural defenses. Your immune system reacts when you receive a vaccination.

To know more about vaccines, visit:
https://brainly.com/question/6683555
#SPJ4

A parallel circuit ha a 12V power pack. It ha 2 branche each with a light bulb on. What i the potential difference of each of the light bulb?

Answers

The potential difference between each of the light bulbs will be 6.

According to ohms law,

V=IR

V=12v

R=2 (2 branches draw current so they serve as resistance)

I=V/R

=12/2

=6 A

This current will serve as the voltage difference between each light bulb.

The potential difference may be a degree of the sum of vitality exchanged between two points in a circuit. Potential contrast is additionally known as voltage and is measured in volts (V).

The potential difference over a component is measured by employing a voltmeter set in parallel with the component. Voltage, moreover, known as electric weight, electric pressure, or (electric) potential contrast, is the distinction in electric potential between two focuses.

In an inactive electric field, it compares to the work required per unit of charge to move a test charge between the two focuses.

Learn more about the potential difference at

https://brainly.com/question/12198573

#SPJ4

Drag each tile to the correct location.
Sort the statements based on whether they describe DNA replication in eukaryotes or prokaryotes.
Replication takes place in
the nucleus.
Replication happens at just
one point on the chromosome.
There is only one origin of
replication.
Replication takes place
in the cytoplasm.
Prokaryotes
G
There are multiple origins
of replication.
Replication occurs at multiple
points along the chromosome.
Eukaryotes

Answers

The nucleus is where replication occurs in eukaryotes. Replication has several different origins. Along the chromosome, replication takes place several times. Prokaryotes replicate within their cytoplasm. Only one location on a chromosome experiences replication. There is just one origin for replication.

The process of DNA replication, which is managed by the enzyme DNA polymerase, involves the genetic material of a cell—in this case, the DNA—making a perfect copy of itself. In comparison to bacteria, which replicate at a pace of about 500 nucleotides per second, mammals replicate at a rate of about 50 nucleotides per second.

Prokaryotic DNA replication happens through a single origin of replication, whereas eukaryotic DNA replication occurs through numerous replication origins. This is the primary distinction between prokaryotic and eukaryotic DNA replication.

Thus, we can conclude that the location, complexity, and size of the cell have a role in the differences between DNA replication in prokaryotic and eukaryotic cells.

LEARN MORE ABOUT DNA REPLICATION HERE:

https://brainly.com/question/16464230

#SPJ1

when a skeletal muscle fatigues, what happens to the contractile force over time?

Answers

When a skeletal muscle fatigues the contractile force declines due to previous contractile activity. Once the muscle has reached maximum tetanic tension, there is no longer an increase in force generated by the muscle. At this stage, the muscle becomes fatigued and contractile force starts to decrease over time.

Due to earlier contractile activity, skeletal muscle weariness results in a decrease in contractile force. The muscle no longer produces an increase in force after it has stretched to its maximal tetanic tension. At this point, the muscle starts to ache and its contractile force starts to gradually decline. A sign of this kind is muscular weariness, which over time reduces the muscles' capacity for work. Sleepiness is only one symptom of fatigue. It may be difficult to get out of bed in the morning due to fatigue. Additionally, it makes it difficult for someone to do everyday duties. Physical exhaustion and mental fatigue are the two main categories of fatigue.

To know more about skeletal muscle visit:
https://brainly.com/question/1560716
#SPJ4

Explain how a change in breathing rate is a homeostatic mechanism for a person at a higher
altitude.

Answers

An increased breathing rate takes in more oxygen to the lungs and bloodstream to maintain oxygen levels.

Why are soft-bodied organisms less likely to leave a fossil trace than hard-bodied organisms?.

Answers

The soft body parts of the organism are more likely to deteriorate when buried inside the earth and hence they do not leave any fossil trace than the hard-bodied organisms.

Fossils are the remains, traces or impressions of the animals and plants that dies millions of years ago and were buried deep down in the Earth. The fossils provide information about the organisms of those times and also help in establishing the ancestral history of current organisms and their evolution.

Evolution is the change in species that occurs in long periods of time for generations over generations. The term evolution is a population concept because evolution can never be seen in one individual but is visible in a population.

To know more about fossils, here

brainly.com/question/2288828

#SPJ4

Proper segregation of plasmids into daughter cells may incorporate which of the following strategies? o Random partitioning due to high copy number
o Polymerization of a filament that binds to, and physically separates plasmids
o Post-segregational killing via toxin / antitoxin system

Answers

Random partitioning due to high copy number, Polymerization of a filament that binds to, and physically separates plasmids and Post-segregational killing via toxin/antitoxin system are the ways incorporated to Properly segregate the plasmids into daughter cells.

Plasmids not only replicate, copying across to a daughter cell when a bacterium divides, but they can also pass between unrelated bacteria via mechanisms such as cell-to-cell contact or a 'bridging connection' in a process known as 'conjugation,' which has been described as the bacterial equivalent of sex.

Plasmid purification consists of three basic steps: bacterial culture growth, bacterial harvesting and lysis, and plasmid DNA purification. Low-copy number plasmids require a segregation mechanism to ensure that one-half of the plasmid copies are distributed to each daughter cell during cell division. This can be accomplished directly by partitioning plasmid copies via a mechanism similar to eukaryotic mitosis.

To learn more about Plasmids, here

https://brainly.com/question/15461017

#SPJ4

perspective that our genes and environmental influences work together to determine our characteristics

Answers

Environmental factors often influence traits independently of genes. Either of these effects can change the proteins that are made from a gene, which in turn affects traits.

How do environment and gene determine our personality?

Some genes increase the characteristic and others work to decrease the same characteristic-complex relationship among the various genes, as well as a variety of random factors, produce the final outcome.

Because of their genetic makeup, individuals differ in their responsiveness to the qualities of the environment. There are unique, genetically influenced reactions to particular experiences to which we are exposed.

The presence of drugs and chemicals in an organism's environment can also influence gene expression in the organism. The environment can affect morphological and physiological development whereas genes influence morphology and physiology, creating a framework within which the environment acts to shape the behavior of an individual.

Hence in this way, genes and environmental influences work together to determine our characteristics.

Learn more about genetic influences from the link given below:

https://brainly.com/question/28218372?utm_source=android&utm_medium=share&utm_campaign=question

#SPJ4

What part of the circulatory system is responsible both for disposing of cellular waste and providing cellular fuel?.

Answers

The lungs are responsible both for disposing of cellular waste and providing cellular fuel.

To obtain oxygen, the circulatory system (cardiovascular system) pumps blood from the heart to the lungs. The heart then sends oxygenated blood to the rest of the body via arteries. The veins return oxygen-depleted blood to the heart to restart the circulation process. Blood vessels in the circulatory system transport blood away from and towards the heart. Arteries transport blood away from the heart, while veins transport blood back to the heart. The circulatory system transports oxygen, nutrients, and hormones to cells while also removing waste products such as carbon dioxide.

The lungs are an important part of the circulatory system because they provide oxygen for cellular respiration and remove waste products.

To learn more about circulatory system, here

https://brainly.com/question/10103458

#SPJ4

HELP PLEASE!!! Match the correct term with the corresponding definition or description.

AND ANSWER ALL!!!!

Answers

The image below has the solution. To read the text, enlarge it.

a(n) cell contains two sets of chromosomes, one set of chromosomes inherited from each parent. multiple choice question.

Answers

A diploid cell contains two sets of chromosomes, one set of chromosomes inherited from each parent.

A diploid cell contains two full sets of chromosomes. With 23 chromosomal pairs totaling 46 chromosomes, diploid human cells predominate. 22 pairs of autosomes and a pair of sex chromosomes make up this.

Chromosomes are arranged in homologous pairs in diploid cells. The term "diploid chromosomal number" refers to how many chromosomes are present in a cell as a whole (2n). In a diploid human cell, there are 46 chromosomes altogether since in this case, 2n = 46.

The DNA from both of the organism's parents makes up the homologous chromosomal pairs; the mother and father each contribute one chromosome to each pair.

To learn more about Diploid cells visit: https://brainly.com/question/1422869

#SPJ1

A student is developing a model of sex cell formation.
X
X
XX
XX
X
t
DI
00
00
Which of the following conclusions can be made from the student's modol of why the dna of the daughter cells is different from the dna of the parent cell?

Answers

Answer:

Can you please include the answer choices....

Explanation:

Thanks. I'll answer it tho.

What is the process in which an mrna molecule is used to synthesize a specific polypeptide on a ribosome?.

Answers

The process in which an m-RNA molecule is used to synthesize a specific polypeptide on a ribosome is called translation.

m-RNA stands for messenger RNA. It is the main coding enzyme that encodes the information from the DNA sequence to be translated to the protein. It is transcribed from the DNA with the help of enzyme RNA Polymerase II in eukaryotic cells.

Ribosome is a nucleoprotein. It is the main machinery for the synthesis of protein. The ribosome is composed of two subunits: a small subunit and  a large subunit. There are two types of ribosomes: 70 S type and 80 S type.

To know more about ribosome, here

brainly.com/question/241631

#SPJ4

What happens when human DNA is inserted into a bacterial plasmid?

Answers

Answer:

creates a so-called recombinant plasmid

Researchers can insert DNA fragments or genes into a plasmid vector, creating a so-called recombinant plasmid. This plasmid can be introduced into a bacterium by way of a process called transformation. Then, because bacteria divide rapidly, they can be used as factories to copy DNA fragments in large quantities.

What is inserting a human gene into a bacterial plasmid?

Recombinant DNA is a technology scientist developed that made it possible to insert a human gene into the genetic material of a common bacterium.

What is it called when DNA is inserted into a plasmid?

In a typical cloning experiment, researchers first insert a piece of DNA, such as a gene, into a circular piece of DNA called a plasmid. This step uses restriction enzymes and DNA ligase and is called ligation.

Thus, by inserting human DNA into a bacterial plasmid, bacteria divide rapidly and they can be used as factories to copy DNA fragments.

To know more about recombinant DNA:

https://brainly.com/question/5996835

#SPJ4

What is the purpose of microtubules during Mitosis?

Answers

The main purpose of microtubles during Mitosis is responsible for the separation and distribution of chromosomes to daughter cells.
Other Questions
why might washintion have fought inequallity privitly insted of opley calling for an end to leagal discrimanation Find the greatest possible error for the given measurement350 mia.0.5 mib. 5 miC.17.5 miD 175 a local small business super clean budgeted and actual results for last year are as follows: master budget actual results price $600 $650 sales volume (units) 5,000 4,500 unit vc $100 $100 fixed costs $250,000 $250,000 a.) please use the given information to complete the budgeted and actual contribution margin statement. master budget actual results sales volume (units) revenue variable costs contribution margin fixed costs profit note: please enter a negative number as, for example, -1000, not (1000). b.) the total profit variance is $ . c.) the sales volume variance is $ . d.) the sales price variance is $ Which relation describes a function? What makes it a function? If you forgot to add the primers to your pcr reaction, what would happen and why?. Select the correct answer.Look again at the claim Zitkla- 's mother makes in paragraph 11:"Both your sister and uncle might have been happy with us today, had it not been for the heartless paleface."Which detail from paragraph 10 best develops this claim? A. Well, it happened on the day we moved camp that your sister and uncle were both very sick. B. Many others were ailing, but there seemed to be no help. C. Her little hands and cheeks were burning hot. D. My poor child, how I cried with her because the Great Spirit had forgotten us! HELP ASAP GIVING BRAINLIEST What was the impact of the 1981 and 1986 tax bills? Why is this change important to progressivity? Find the equation of the line passing through the given point and parallel to the given line.( 1, 9 ), y = 4x + 2( 5 , 2 ), y = -2x + 7 the decomposition of hi(g)hi(g) at 298k298k is represented by the equilibrium equation above. when 100.torr100.torr of hi(g)hi(g) is added to a previously evacuated, rigid container and allowed to reach equilibrium, the partial pressure of i2(g)i2(g) is approximately 3.7torr3.7torr. if the initial pressure of hi(g)hi(g) is increased to 200.torr 200.torr and the process is repeated at the same temperature, which of the following correctly predicts the equilibrium partial pressure of i2(g)i2(g), and why? 6) how does the reformation contribute to the growth of political liberty; advanced the idea of equality; create of an individualistic ethic; and develop the capitalist spirit? how many miles was it from tuwat to cairo The graph below shows distance over time.A student is walking to class. The student increases their speed for 20 seconds for 3 meters. The student then walks a constant speed for 5 seconds and then increases their speed the last 3 meters to class. Which of these situations could be represented by this graph? What is 125 in simplest form? which intervention would be most important when caring for the client with breech presentation confirmed by ultrasound? how many distinct 5-letter strings can be created using the letters a, b, c, d, e if repetition is allowed, but the letters a appears at most twice? why were gloworms useful to soldiers The tens digit of a two-digit number is twice the ones digit. Its reversed number is 36 less than the original number. Now imagine the robot only sees two landmarks, a pile of rocks and an umbrella. The rocks are at the position (10,0) and the umbrella is at the position (20,0). The distance to the rocks is 5 meters, and the distance to the umbrella is also 5 meters. Can you still determine the position of the robot, even though there are only two landmarks? deposit of blanks in cold climates are evidence of continental drift show that anitartica was once near