Answer:
Option C
Explanation:
Given ,
A1 allele is carried by [tex]70[/tex] % people
Let us assume A1 s dominant genotype
This means [tex]p= \frac{70}{100} = 0.7[/tex]
Thus, frequency of allele in the given population is [tex]0.7[/tex]
It is also given that the population is in Hardy-Weinberg equilibrium thus
[tex]p+q=1\\0.7+q=1\\q = 1-0.7\\q= 0.3[/tex]
Frequency of fruit fly with genotype A2A2 will be
[tex]q^2\\= (0.3)^2\\= 0.09[/tex]
As per Hardy-Weinberg's second equation of equilibrium
[tex]p^{2} + q^{2} + 2pq = 1\\0.49+0.09+2pq = 1\\2pq = 1-0.49-0.09\\2pq= 0.42[/tex]
Hence, option C is correct
Fossilized stromatolites
(A) formed around deep-sea vents.
(B) resemble structures formed by bacterial communities that are found today in some shallow marine bays.
(C) provide evidence that plants moved onto land in the company of fungi around 500 million years ago.
(D) contain the first undisputed fossils of eukaryotes.
Answer:
(B) resemble structures formed by bacterial communities that are found today in some shallow marine bays.
Explanation:
Extant stromatolites represent real "living fossils" for they are decendents of ancient forms that are associated with one of the first living forms on earth. Particularly, stromatolites are real bacteria communities where the autotrophic organism of the community are represented by cyanobacteria, which live along with heterotrophic bacteria. This clearly indicates that fossilized stromatolites points to bacteria (prokaryotes) as the first living things on earth (dated with not less than 3.5 billion year old)
Nowadays, stromatolites with cyanobacteria allows to reconstruct and understand fossilized forms. These current structures live in shallow marines ambients (e.g. Australia) but also in continental salt flats (e.g. Argentina) where few others bacteria can survive to these extreme conditions (high light exposure and salt concentration).
Stromatolites are sedimentary formations created by cyanobacteria that resemble structures found today in some shallow marine bays. They provide key insight into early photosynthetic life on Earth.
Explanation:Stromatolites are layered mounds, columns, and sheet-like sedimentary rocks that were originally formed by the growth of layer upon layer of certain cyanobacteria, a primitive form of photosynthetic life. Option (B) is correct - Stromatolites resemble structures formed by bacterial communities that are found today in some shallow marine bays. The cyanobacteria secrete a sticky substance to which sediment adheres, and if conditions are right and undisturbed by other organisms or strong currents, a new layer of cyanobacteria grows over it and the process repeats, leading to the formation of a fossilized layered structure.
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Mutations that occur without a known cause are known as:
a. spontaneous mutations
b. induced mutations
c. harmful mutations
d. adaptive mutations
e. reversion mutations
Answer:
a. spontaneous mutations
Explanation:
Spontaneous mutations occur randomly in all cells and without any agents. Induced mutations are the result of some exposure to a physical or chemical agent called a mutagen. Mutations can be classified as harmful and adaptive regardless of whether they were spontaneous or induced mutations. The reversal mutation is when a given mutation is reversed by another mutation so that the nucleotide is changed back to its original state.
Define reading frame and discuss its significance to the genetic code.
Basically, a reading frame is the result of DNA or RNA nucleotide sequencing in non-overlapping triplets. It's like taking the strand of DNA and / or RNA and stretching it into a straight line. Thus, all nitrogenous bases would be in sequence and aligned as in a row. Each three nitrogenous bases (codon) encodes a protein.
The reading structure has revolutionized the field of genetics and evolution, since we can see the sequencing of the genes of individuals, we can make comparisons between their DNAs to discover possible evolutionary relationships between them. In addition, it is also very important in medicine to locate sequences where there are genetic mutations (base exchanges or subtractions).
If photosynthesis is happening which of the following would you expect to happen? Choose all that apply.
a. 02 levels will rise
b. CO2 levels will rise
c. O2 levels will fall
d. CO2 evels will fall
Answer:
The correct answer will be options-A and D.
Explanation:
Photosynthesis is a complex process which forms the glucose, the energy molecule of the plant. Photosynthesis takes place in the two phases: light-dependent reaction and light-independent reactions.
The light-dependent reaction leads to the breakdown of the water molecule which produces oxygen whereas in light-independent reaction, the carbon dioxide gets fixed during the carboxylation step of cycle utilizing the carbon dioxide.
Therefore, if photosynthesis takes place then it will lead to a rise in the level of oxygen and reduction in the amount of carbon dioxide. Thus, options-A and D are the correct answer.
During photosynthesis, plants use carbon dioxide to create glucose and release oxygen. Hence, O2 levels rise, and CO2 levels fall.
Explanation:In the process of photosynthesis, plants use sunlight to convert water and carbon dioxide (CO2) into glucose and oxygen (O2). Thus, during photosynthesis, you can expect that the levels of carbon dioxide (CO2) will fall as it is being used up, and the levels of oxygen (O2) will rise as it is being produced. So, the correct choices would be: a. O2 levels will rise, and d. CO2 levels will fall.
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what happens to the molecules of water when the temperature of water increases?
Answer:
Water carries several physical properties such as chemical formula, appearance, boiling point, freezing point, density, viscosity and solvency.
An increase in temperature changes the density of water. When a water is heated or its temperature is allowed to increase it causes the water molecules to gain energy and move faster, which results in increase in water volume due to movement of water molecule far from each other. on the other side if temperature of water is decrease, it's molecules come closer to each other and decrease in the volume of water takes place.
Most amino acids are specified by two to four different codons. This means that the genetic code is:
a. nonoverlapping
b. degenerate
c. ordered
d. non-degenerate
e. universal
Answer:
Degenerate.
Explanation:
Genetic code may be defined as the codons of three nucleotides that can be inherited to the next generation. The codons codes for the particular amino acids.
The degeneracy of the genetic code means the a single amino acids is coded by more then one codons. For example: Leucine is coded by UUG as well as UUA.
Thus, the correct answer is option (b).
A controlled experiment is one that
a. proceeds slowly enough that a scientist can make careful records of the result.
b. tests experimental and control groups in parallel.
c. is repeated many times to make sure the results are accurate.
d. keeps all variables constant.
A controlled experiment is one that tests experimental and control groups in parallel, with all other variables kept constant. This enables the scientist to observe the impact of a single variable.
Explanation:A controlled experiment is one that can be defined as an experimental set up in which the scientist keeps all variables constant, except for the one being studied. The correct option here would be option 'b'. Such an experiment tests experimental and control groups in parallel.
This methodology allows the researcher to observe the effect of one variable on the study subject while ensuring that all other conditions remain the same. For example, if you were to experiment with plant growth, you might keep factors like sunlight, water, and type of soil constant while changing the type of fertilizer used.
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Which of the following is a type of tissue in plants that is dead at maturity?
a. Parenchyma
b. Sclerenchyma
c. Collenchyma
d. All of these are alive at maturity.
Answer:
The correct answer will be option-B.
Explanation:
The plant tissues are composed of three types of cells: parenchyma, collenchyma and sclerenchyma.
The parenchyma and collenchyma remain alive at their maturity but sclerenchyma loses their protoplasm and become dead. These cells deposit lignin in their secondary walls and form hard tissues of the plant-like hard shell of a coconut. Sclerenchyma provides mechanical strength to the plant.
Thus, Option-B is the correct answer.
Which of these are found in both eukaryotes and prokaryotes (choose all that apply)
a. Centromere
b. replication bubbles
c. telomeres
d. replication forks
Answer:
The correct answers are option b. "replication bubbles" and d. "replication forks".
Explanation:
The nucleic acids replication systems share some similarities between eukaryotes and prokaryotes. For instance, both organism have replication bubbles. However, prokaryotes have a single replication bubble because its replication process starts from a single origin, while eukaryotes have several replication bubbles. Also, the replication forks are well conserved from prokaryotes to eukaryotes with only some differences among the enzymes present within the fork.
The term cancer means
A) out of control.
B) cell division.
C) crab
D) lobster
Answer: B) Cell Division
Explanation: Cancer is the rapid division of cells. It comes in many forms (Eg: Brain Cancer, Breast Cancer) and can be deadly.
Which of the following represents the number of premolars in deciduous dentition of teeth in humans?
a. 2
b. 4
c. 8
d. 12
e. 0
The correct answer is E. 0
Explanation:
The deciduous dentition or baby teeth refer to the first set of teeth human have before the permanent teeth, these teeth are prevalent during infancy and include 20 teeth: 4 central incisors, 4 lateral incisors, 4 canines and 8 molars divided into 4 primary molars and 4 secondary ones. In the case of premolars, these are part of permanent teeth but not of deciduous teeth as they only appear after deciduous teeth begin being replaced and these replace the molars in deciduous dentition. Thus, the number of premolars in deciduous dentition in humans is 0.
Which of the following traits evolved multiple times over the course of the evolution of vertebrates?
a. Hair
b. Flight
c. Oviparity
d. Homodonty
Answer:
The correct answer is option b, that is, flight.
Explanation:
Our atmosphere is comparatively thick, and it possesses the tendency of supporting the creatures, which are light. The factual flight, however, relies upon the fact that whether an individual is sufficiently light, and is equipped with appropriate characteristics, and has a desire to make a since the attempt to make aloft.
The birds are the most apparent fliers in the world we live in. The first bird appeared in the fossil about sixty-five million years ago. Like birds, bats also have developed an elegant approach to flight. Similarly to birds, they exhibit lightweight and slender bones, and a compact skeleton, and have developed strong muscles for flapping flight.
Final answer:
b) Flight is the trait that evolved multiple times in vertebrates, with different species developing unique wing structures through convergent evolution.
Explanation:
The trait that evolved multiple times over the course of the evolution of vertebrates is flight. Flight has evolved independently in different vertebrate lineages through a process known as convergent evolution. This is evident in the wings of pterodactyls, birds, and bats, which are structures adapted for the purpose of flight, but each has a unique anatomical development despite the forelimbs being homologous structures. On the other hand, hair has evolved only in the lineage leading to mammals, and oviparity, though widespread, is not an example of multiple independent evolutionary events. Homodonty, the condition of having teeth uniform in shape, may have appeared in different lineages but is not as clear an example of repeated evolution as flight. The development of traits like a high metabolism, a four-chambered heart, and other modifications have supported the evolution of flight in vertebrates.
Predict phenotypes associated with nondisjunction of sex chromosomes.
Answer: The new daughter cells will have an abnormal amount of genetic material. That is called aneuploidy and it is the presence of an abnormal number of chromosomes. Different clinical conditions are the result of this nondisjunction.
Explanation:
Normal cells are diploids, that means they have two copies of each gene, one of each chromosome. So normal cells have two homologous chromosomes, one from each parent.
During anaphase of cell division, each pair of chromosomes is separated by the mitotic spindle. The separated chromosomes are then pulled by the spindle to opposite poles of the cell, and eventually will end up in the new daughter cells.
Nondisjunction is the failure of homologous chromosomes to separate properly during cell division, so it is the miss segregation of them. The new daughter cells will have an abnormal amount of genetic material. Different clinical conditions are the result of this nondisjunction.
Sex chromosomes participates in sex determination of an individual. Females have two X chromosomes (XX), while males have one X and one Y chromosome (XY) So nondisjunction of sex chromosomes could be:
XX: one cell with no chromosome and the other cell with two X chromosomes.XY: one cell with no chromosomes and the other cell with XY chromosomes.According to which gametes are fused during fertilization, different phenotypes can be given. For example, if a gamete with one chromosome fuses with another gamete with two chromosomes, the result will be an individual with three chromosomes (it could be XXY, or XXX) called trisomy.
Triple X syndrome is characterized by an extra X chromosome in females. Those affected are often taller than average, but most females have a normal sexual development. Klinefelter syndrome is known XXY individuals, and it causes infertility in males, breast growth, less body hair and weaker muscles.
And if a gamete with no chromosome fuses also with another gamete with no chromosome, the result is a nullisomy. But due to the lack of genetic material, the nullisomic gametes are rendered unviable for fertilization.
And if a gamete with no chromosome fuses with another gamete with one chromosome (normal) the result is a monosomy, the presence of only one chromosome from a pair. The result can be an individual who is X or Y. People with Turner syndrome have one X chromosome and it is the only monosomy that is seen in humans because other cases monosomy are lethal.
Any of those examples is called aneuploidy and it is the presence of an abnormal number of chromosomes.
Simply, translation is a copy of _______________
a. DNA from mRNA
b. DNA from DNA
c. protein from RNA
d. RNA from DNA
Answer:
c. protein from RNA
Explanation:
Translation is a process that occurs in the ribosomes where tRNA is used to read the mRNA strand and translate the codons into complementary amino acids.
Explain the biological basis for assigning all human populations to a single species. Can you think of a scenario by which a second human species could originate in the future?
Answer:
Molecular biology (DNA sampling) is the best proof.
Explanation:
An study published in the journal of science found that 99.9% of humans are quite similar. The scientific team analysed DNA from 1,056 people from 52 populations in Africa, Eurasia (Europe, the Middle East, Central and South Asia), East Asia, Oceania and the Americas.
The phenotype ( visible appearance) results from a very small proportion of differences in genetic traits, hence the concept "race" is more a cultural concept than a biological concept.
You are trying to figure out what molecule, DNA, RNA, or protein, is responsible for making your bacterial cell lysate turn blue when you add a certain chemical. You divide your lysate into 4 tubes and add (a) Nothing, (b) protease, (c) RNase, and (d) DNase. Then you add your chemical of interest to each tube. Tubes (a), (b), and (d) turned blue but (c) remained colorless. You conclude:
a. The molecule responsible for making the blue color is DNA.
b. Your RNase didn't work.
c. The molecule responsible for making the blue color is RNA.
d. The molecule responsible for making the blue color is a protein.
Answer:
c. The molecule responsible for making the blue color is RNA.
Explanation:
Tube (a): DNA, RNA and proteins present ⇒ BLUE
Tube (b): DNA and RNA present ⇒ BLUE
Tube (c): DNA and proteins present ⇒ COLORLESS
Tube (d): RNA and proteins present ⇒ BLUE
RNA is the only molecule that is present every time the chamical is added and the tubes turn blue, and not present when the color doesn't change, meaning in tube (c) there's no reaction with the added chemical.
In conclusion, RNA is the only molecule reacting with the chemical and responsible for blue appearance.
What is the correct scientific name for the cane toad?
a. Bufo
b. Bufo Marinus
c. Marinus
d. Cane toad
Answer:
The correct answer is option B. Bufo Marinus.
Explanation:
The cane toad a american species of toads that is known as its scientific name Rhinella marina which is formerly known as Bufo Marinus. Commonly called neotropical toad which is large, land toad found in central and south America.
These toads are the world's largest toads that are known for their invasive properties as they grow and reproduce incredibly fast.
Thus, the correct answer is option B. Bufo Marinus.
During purification of many cytosolic proteins, it is important to
include either dithiothreitol or b-mercaptoethanol in the
buffers. Why?
Answer:
To reduce thiol-groups of the protein
Explanation:
Dithiothreitol of b-mercaptoethanol act as reducing agents. Including them in a buffer would prevent oxidation of thiol-groups in amino acids of the protein and preventing its denaturation.
The strong force is one of the four fundamental forces of the universe and it holds protons and neutrons in the nuclei of atoms.
a. True
b. False
Answer:
The given statement is true.
Explanation:
In the nuclei atoms we know that there are 2 type of particles named protons and neutrons.As we know that the neutrons are uncharged and protons are positively charged thus in such a close proximity when the proton's are just touching each other the electrostatic forces of repulsion between the particles becomes exceedingly large thus rendering the nucleus theoretically unstable. But as we know that the nucleus is inherently stable indicating that there is another type of force that must act between the nucleons (proton's and neutrons) this fundamental force is known as strong nuclear force and is the strongest force among the 4 fundamental forces in nature.
Answer:
true
Explanation:
hope it helped
Explain the differences between prokaryotes, eukaryotes and mitochondria(eukaryotic organelle). Which 2 of those 3 are most similar?
Eukaryotic
Cells with a differentiated nucleus that contains all the DNA, limited by nucleus membrane, and has a cytoplasm limited with the plasma membrane that contains organelles.
The ribosomes are bigger, 80 S (svedbeg is the measuring unit)
Procaryotic
All its genetic material spread on the cytoplasm.
This kind of cell does not have organelles. All biologic processes made in specific places in the plasma membrane.
The ribosomes are smaller, 70 S.
Mitochondria
It's an organelle you can find inside a eukaryotic cell.
It has two membranes, one outsider, and one insider.
The insider one has folded.
Scientific believe that millions of years ago, the mitochondria was a bacteria and the eukaryotic cell phagocyte it and became part of it.
The ribosomes are the same size that procaryotic cells.
Which of the following statements about eukaryotic mRNA processing is not correct?
a. the mRNA transcript must be exported from the nucleus.
b. a 5' cap and a 3' poly(A) tail must be added
c. the introns are removed
d. a 3' cap and a 5' poly(A) tail must be added
e. exons are spliced together to form the mRNA transcript
Answer:
The correct answer will be option-D.
Explanation:
In eukaryotes, the process of transcription takes place inside the nucleus whereas translation takes place in the cytosol. So, mRNA has to export to the cytosol from the nucleus.
Before export, the post-transcriptional modification takes place like 5' capping, 3' tailing and splicing mechanism.
The capping is done at 5' end by adding modified guanine (G) nucleotide which protects the mRNA from exonuclease activity and tailing is done at 3' end by adding adenine nucleotides which provides stability to the mRNA.Splicing removes the junk DNA called introns and joins the exons before export.
Thus, option-D is the correct answer.
The incorrect statement about eukaryotic mRNA processing is 'a 3' cap and a 5' poly(A) tail must be added.' In actuality, a 5' cap is added and a 3' poly(A) tail is added.
Explanation:The statement that is not correct about eukaryotic mRNA processing is: 'd. a 3' cap and a 5' poly(A) tail must be added.'
In eukaryotic mRNA processing, there are several modifications made. Firstly, a 5' cap is added to the beginning of the mRNA molecule, not a 3' cap. Additionally, a poly(A) tail is added at the 3' end, not the 5' end. Therefore, option 'd' is incorrect. The rest of the modifications, which include the removal of introns, the export of the mRNA transcript from the nucleus, and the splicing together of exons to form the final mRNA transcript, are correct.
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Which of the following is NOT a hormonal type of contraception?
A. Depo-Provera
B. Contraceptive diaphragm
C. Injectable progestin.
D. Birth control patch.
E Oral contraceptives.
Answer:
The correct option is: B. Contraceptive diaphragm
Explanation:
Contraception, also known as birth control, are the various methods like barrier methods, hormonal contraception, sterilization, intrauterine devices, and behavioral methods, that are used to prevent pregnancy.
The hormonal method of contraception includes vaginal rings, injections, patches and oral contraceptive pills. This contraceptive method involves the use of steroid hormones- estrogen, progestin, and progesterone.
Whereas, the barrier method of contraception includes condoms, contraceptive sponges, diaphragms and the fertility awareness methods.
Therefore, contraceptive diaphragm is not a hormonal method of contraception.
All of the following are respiratory enzyme complexes involved in the electron transport chain except?
a. NADH dehydrogenase
b. NADPH dehydrogenase
c. Cytochrome C reductase
d. Cytochrome C oxidase
Answer:
NADPH dehydrogenase.
Explanation:
Electron transport chain may be defined as the sequential steps of transfer of electrons through the complexes and couple with proton gradient. The ATP is generated by the electron transport chain.
NADPH dehydrogenase is an ezymes that are used for the conversion of NADPH into NADH+. The NADH dehydrogenase is complex I of the electron transport chain. The NADPH dehydrogenase is not the enzymes complexes and not involved in the electron transport chain.
Thus, the correct answer is option (b).
Final answer:
The electron transport chain in mitochondria does not include NADPH dehydrogenase, which is instead associated with processes like photosynthesis. The other complexes listed are involved in the different steps of the mitochondrial electron transport chain. So the correct option is a.
Explanation:
The subject of this question is the respiratory enzyme complexes involved in the electron transport chain, specifically which one is not part of this process. The correct answer to the question is b. NADPH dehydrogenase. The other options provided are indeed part of the electron transport chain, as follows:
Complex I (NADH dehydrogenase or NADH-coenzyme Q oxidoreductase) accepts electrons from NADH.Complex III (Cytochrome C reductase) receives electrons from coenzyme Q and passes them to cytochrome c.Complex IV (Cytochrome C oxidase) receives electrons from cytochrome c and completes the electron transport chain by reducing oxygen to water.NADPH dehydrogenase is not a component of the mitochondrial electron transport chain; rather, it is associated with other processes such as photosynthesis in plants.
A large percentage of bacteria are harmful to humans and cause disease.
a. True
b. False
Answer:
The correct answer is b. False
Explanation:
More than 90% of bacteria present in the world is not harmful to human beings. Human body contains trillions of bacteria in their intestine which play important role digestion of food absorption of nutrients inside the small intestine.
Human gut contains 10 times more bacteria than the cells present in human body. This proves that bacteria lives in symbiotic association with humans and human body cannot survive without them.
Thus a large percentage of bacteria are not harmful to humans rather they are important part of human body and these bacteria are called human microbiota.
Explain what is meant by the antiparallel polarity of the two strands of DNA within the double helix.
Answer:
The two DNA strands have anti parallel polarity which means that they are directional and anti parallel to each other. The polarity to these strands is conferred by the deoxyribose sugar molecule in nucleotide. The sugar molecule has 5 Carbon atoms. The third carbon is attached to an OH group and the fifth carbon is attached to a phosphate molecule. This asymmetry is responsible for giving DNA molecule a direction.
The double helix structure has both these strands in opposite direction so that the 5 prime carbon of one strand faces the 3 prime carbon of another. The anti parallel structure of DNA strands lets the base pairs complement each other. Anti parallel structure is also more stable than parallel structure.
From which part of the embryvo are embryonic stem cell lines derived?
Answer:
Undifferentiated inner cell mass
Explanation:
Human embryo has two types of cells in its initial stage, trophoblast and inner cell mass. Trophoblast forms the placenta and inner cell mass form the entire human body. Inner cell mass are pluripotent in nature i.e. they can give rise to any body part under right conditions.
Embryonic stem cells are derived from the inner cell mass. They are derived from pre implantation embryo since after implantation the inner cell mass begins to differentiate. Embryonic stem cells can replicate indefinitely without differentiating. They can give rise to all the three germ layers: ectoderm, mesoderm and endoderm. They can treat a number of disorders like genetic disorders, Parkinson's, spinal cord injury, cancers etc.
A cancerous tumor eventually grows faster than surrounding tissues because a greater proportion of its cells are dividing. True or false?
A) true
B) false
C) none of the above
Describe the path that air takes as it enters and passes through the human respiratory system.
Answer:
In our respiratory system, there is a pair of external nostril situated above the upper lip that receives atmospheric air and passed to the pharynx (a common passage for air and food). The pharynx passed this air to the trachea via larynx (known as the soundbox). The trachea is an extended part which is divided into left and right primary bronchi. Bronchi divide into secondary bronchi, tertiary bronchi, and bronchioles that ending up in thin terminal bronchioles. Each terminal bronchiole constitutes a number of irregular-walled, thin and vascularised bag-like structures called alveoli which are the primary sites of gases exchange.
How does the hypothalamus monitor water in the body?
A. If blood is too concentrated, the hypothalamus nerve cells will contain too much salt.
B. If blood is too concentrated, the hypothalamus it registers dehydration in its own cells.
C. If blood is too concentrated, the hypothalamus registers ADH in the blood.
D. If blood is too concentrated, nerve cells in the hypothalamus it has nerve cells that lose water by osmosis and fire more slowly.
E. If blood is too concentrated, in the hypothalamus it registers that its cells are losing water by osmosis.
Answer:
The correct answer will be option-C.
Explanation:
Hypothalamus is a part of the brain which controls many important functions of the body by producing hormones.
When the amount of water gets reduced in the blood, it leads to a change in the osmolarity which can be easily detected by the osmorecpetors present in the neurons of the hypothalamus.
In response, neurons secrete Anti-diuretic hormone in the blood which acts in the tubules of the kidney where they help in re-absorption of the water from the body.
Thus, Option-C is the correct answer.
Relate the structure of DNA to its function.
Answer:
Explanation:
DNA is deoxyribose nucleic acid. It is a double helical structure. It remains in the coiled form so as to make the information stored in the small region within the cell. The sequence of bases allows the information to be stored in the coded form so as to promote the synthesis of proteins. Complementary base pairing allows the DNA molecule to replicate itself.