The first known single-celled organisms appeared on Earth about 3.5 billion years ago, roughly a billion years after Earth formed. More complex forms of life took longer to evolve, with the first multicellular animals not appearing until about 600 million years ago.
I think it’s Proterozoic era where life on Earth was mostly single-celled and small.
What factor or factors are considered when a cell cultures environment is made as similar as possible to a cells natural surroundings?
A. Light microscope
B. Temperature
C. Number of variables
D. Agar and Petri dish
Answer:
B. temperature
Explanation:
Temperature is a factor considered when a cell cultures environment is made as similar as possible to a cells natural surroundings
The propagation of cells outside the organism of origin is called cell culture, these techniques allow the maintenance of cells 'in vitro', maintaining their properties to the maximum under controlled conditions.
The environment of the cell culture can be influenced by the nature of the substrate (solid, semi-solid or liquid), the contact with other cells, the constitution of the medium and the temperature.
In a cell culture, the physical-chemical conditions (pH, temperature, osmotic pressure, partial pressure of O2 and CO2), and physiological conditions (hormones, growth factors, etc.) can be controlled.
To establish a defined environment, it is necessary to know precisely the nutritional needs of the cells in question.
The optimal temperature for cell culture depends mainly on the body temperature of the organism from which the cells were obtained, to obtain reproducible results, consistency in temperature must be ensured.Temperature also influences the pH of the culture medium, because at low temperatures CO2 dissolves more.Therefore, we can conclude that temperature considered when a cell cultures environment is made as similar as possible to a cells natural surroundings.
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what do we call the chemical that cells need to work and reproduce?
cells need many chemicals, but its DNA
Which is an accurate description of the processes used to turn dna code of a gene into a protein
Answer: Transfer RNA delivers specific amino acids to the ribosome, matching messenger RNA codons.
Explanation:
“E.coli can be considered a manufacturing unit in the field of genetic engineering” explain this statement.
it means E.coli can be produced in the field of work and all that
what is meristem and where is the meristem located in a plant?
Meristems are classified by their location in the plant as apical (located at root and shoot tips), lateral (in the vascular and cork cambia), and intercalary (at internodes, or stem regions between the places at which leaves attach, and leaf bases, especially of certain monocotyledons—e.g., grasses).
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Meristem, region of cells capable of division and growth in plants. A meristem is the tissue in most plants containing undifferentiated cells (meristematic cells), found in zones of the plant where growth can take place.
Continental drift was first proposed by scientist named Alfred
Alfred Wegener in 1912
The idea that species evolve at a slow constant rate is called
The idea that species evolve at a slow constant rate is called gradualism.
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Answer:gradualism.A policy of gradual reform rather than sudden change or revolution.
◦ BIOLOGY
the hypothesis that evolution proceeds chiefly by the accumulation of gradual changes (in contrast to the punctuationist model).
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Describe how seismologists discovered that most of the mantle is solid.
The major boundaries of the Earth's interior were discovered by seismologists. In 1909, Andrija Mohorovičić, a Croatian seismologist, discovered the boundary between the crust and the mantle by observing the sudden increase of seismic waves as they passed from the crust to the mantle.
Seismologists discovered that most of the mantle is solid by evidence from seismic waves, heat flow, and meteorites.
What is the mantle?A mantle is a layer within a planet that is bordered below by the core and above by the crust. Mantles are composed of rock or ice and are the largest and most massive layer of a planet. The top and lower mantles differ little, but the lower mantle is more substantial than the higher.
Seismologists discovered the major boundaries of the Earth's interior. In 1909, Croatian seismologist Andrija Mohorovii discovered the border between the crust and the mantle by noting the dramatic increase in seismic waves as they moved from the crust to the mantle.
Therefore, proves from seismic waves, heat flow, and meteorites led seismologists to the conclusion that the majority of the mantle is solid.
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when is speciation complete?
A. When the two populations can no longer interbreed
B. When gene flow increases
C. When an allele becomes fixed
D. When part of the population has a new trait
Answer: A. When the two populations can no longer interbreed
Explanation:
Speciation is a process in which the members of the same population of a species get separated due to geographical, physical, behavioral, and temporal barriers. The separated members develop new traits and becomes a new species.
Among the given options, A. When the two populations can no longer interbreed is the correct option because if the members of the same population will longer interbreed they may experience reproductive isolation from the separated members and with the coarse of evolution they will develop traits which will be responsible for the development of new species. Hence, speciation will complete.
Answer:
When two populations can no longer interbreed
Explanation
where does the energy come from to produce new molecules?
Answer:
Atoms used energy to make new molecules through making bonds with one another because bonds allow atoms to attached tightly with each other. The energy come from the external environment in order to produce new molecules. So we can conclude that energy is the main ingredient needed for making new molecules and this energy is gained from the environment.
Explanation:
The energy required to produce new molecules comes from various sources such as sunlight, chemical energy, and thermal energy. In photosynthesis, for example, the energy from sunlight is used to convert carbon dioxide and water into glucose and oxygen.
What is released during cellular respiration?In cellular respiration, glucose and other organic molecules are broken down to release energy for the production of ATP, the energy currency of the cell.
The energy released during the breakdown of these molecules is then used to fuel various cellular processes including the synthesis of new molecules. In addition, some organisms can derive energy from chemical reactions, such as chemosynthesis, in which inorganic compounds are used to produce organic molecules.
The energy required for the production of new molecules ultimately comes from the conversion of one form of energy to another.
In addition to ATP, energy can also come from other sources such as light, heat, and chemical gradients. For example, in photosynthesis, the energy to produce new organic molecules comes from sunlight, which is captured by pigments such as chlorophyll and used to drive the synthesis of glucose and other sugars.
In chemosynthesis, bacteria use the energy from chemical gradients, such as those created by the oxidation of hydrogen sulfide, to produce new organic molecules.
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DNA is made up of pairs of nitrogenous bases. Which of the following nitrogenous bases is paired correctly?
im pretty sure that the answer is C. Thymine-adenine
Answer:
The correct answer will be option-C.
Explanation:
DNA is made up of nucleotides which are composed of the five-carbon sugar deoxyribose, a phosphate group and four types of the nitrogenous base.
The nitrogenous base remains perpendicular to the backbone made of the sugar and phosphate. The bases bonds to each other following a rule suggested by the Chargaff.
Chargaff rule stated that purine will bind complementary pyrimidines like adenine will bind thymine and guanine will bind cytosine. Thus, Option-C is the correct answer.
Based on the food web below, which of the following is a consumer?
a herbivore? feeding on plants
Answer:
mouse , rabbit , fox
Explanation:
**MULTIPLE ANSWERS**
The body has many responses to injuries, diseases and other conditions that alter its normal function. Select the statements that indicate the body's responses to an injury, such as a cut.
A) Platelets join together to form a clot.
B) Macrophages collect damaged cells and other foreign substances.
C) Red blood cells transport pathogens to the injury site.
D) If the wound is infected, fever may occur to heighten the immune response.
E) Cytokines alert the immune system to possible infection.
F) The central nervous system reduces signals from the area to decrease pain.
A, B, D, E should be the correct answers.
Hope this helps.
The statements that indicate the body's responses to an injury include the
following:
Platelets join together to form a clot.Macrophages collect damaged cells and other foreign substances.If the wound is infected, fever may occur to heighten the immune response.Cytokines alert the immune system to possible infection.During injuries, the body's immune system responds through various
mechanisms such as release of chemicals. This helps to ensure proper
healing and prevent cells from being infected.
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one of the few examples of displacement in the animal kingdom Is? a. the waggle dance of the honey bee. b. chimpanzees being unable to suppress calls. c. juvenile beret monkey mistakes in their call systems
Displacement behavior usually occurs when an animal is torn between two conflicting drives, such as fear and aggression. Displacement activities often consist of comfort movements, such as grooming, scratching, drinking, or eating. It has been scientifically proven that the honey does a waggle dance during behavioral transitions when they are foraging.
A) the waggle dance of the honey bee is the answer.
Final answer:
Displacement in the animal kingdom is exemplified by the waggle dance of the honey bee, through which worker bees can signal the location of distant food sources to their hive.
Explanation:
One of the few examples of displacement in the animal kingdom is the waggle dance of the honey bee. This innate behavior allows worker honey bees to communicate the existence and location of a food source that is situated some distance away from their hive.
The waggle dance involves a figure-eight motion, which conveys both the distance and direction to the nectar. Moreover, bees take into consideration the movement of the sun as they perform their dance. However, it is important to note that a honey bee must have seen the nectar first in order to conduct this dance. In contrast to human language, animals typically do not communicate about things they have never seen before.
Explain the relationship between crossing over and genetic variation
Answer:
Crossing over is the process by which genetic material is exchanged by non-sister chromatids during meiosis.
Crossing over results in a new combination of genetic information for the cell for a specific trait.
Crossing over ensures that organisms are not identical from generation to generation.
Genetic recombination allows for a variation in genetic material that is passed through the generations.
Explanation:
Which is most likely a limited resource for the smaller trees. Energy. Reproduction. Shelter. Water
Limited sunlight is a key resource likely to be limited for smaller trees, due to overshadowing by larger trees. While water and nutrients may also be restricted, sunlight is crucial for photosynthesis and growth.
The most likely limited resource for smaller trees is access to sunlight. This is because trees, particularly smaller ones in densely forested areas, compete for sunlight to perform photosynthesis, which is critical for their growth and energy production. Larger trees often overshadow smaller ones, limiting their sunlight exposure. Water availability could also be a limiting factor; however, smaller trees have less extensive root systems and therefore require less water than mature trees. Additionally, nutrients in the soil are essential for tree growth, and smaller trees might struggle if they are in competition with larger trees with more established root systems. In contrast, reproduction, shelter, and defense against herbivory are unlikely to be as influential since these factors do not directly affect the immediate growth and survival of smaller trees in the same way that access to sunlight and other resources do.
The simplest animals to have body symmetry are
A. Sponges
B. Algae
C. Cnidarians
D. Echinoderms
Answer: C.) Cnidarians
The simplest animals to demonstrate body symmetry are Cnidarians, including animals like jellyfish, anemones, and corals. They present radial symmetry, meaning any cut along the central axis gives two identical halves.
Explanation:The simplest animals to have body symmetry are Cnidarians. Body symmetry refers to the balance in size, shape, and position of an animal's body parts. Cnidarians, which include jellyfish, anemones, and corals, possess radial symmetry. This means they can be divided into two identical halves in any plane along their central axis. This is unlike Sponges which are asymmetrical, meaning they do not have an organized body plan, whereas Algae are not even considered animals. Echinoderms do have symmetry, but they are more complex animals than Cnidarians.
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what must occur before replication can begin?
Answer:
The two DNA strands must separate
Explanation:
This separation is mediated by DNA helicases enzymes. Using ATP energy, they breakdown the hydrogen bonds between the two strands of the double helices giving access of DNA polymerase to single-stranded DNA required for replication. The DNA polymerase can only bind to single-stranded DNA.
Select the correct answer.
A family has a Y-linked disease that affects the father. What is the chance of a male offspring inheriting the same disease?
A.
100%
B.
50%
C.
25%
D.
0%
Answer:
a
Explanation:
100%
Answer:
The correct answer is letter A.
Explanation:
Men have a Y chromosome and an X chromosome, while women have two X chromosomes. So, a daughter (female offspring) has the X chromosome from the father and another one similar from the mother. On the other hand, the son (male offspring) would have one X chromosome from the mother and the Y chromosome from the father, so the answer is 100%.
The first law of thermodynamics states that ___.
1. When a process converts energy from one form to another, some energy converts into heat, an unusable form of energy
2. Energy can neither be created nor destroyed, but it can change from one form to another
3. Energy flows through ecosystems without being recycled
4. Most energy in ecosystems comes from the Sun
Your answer would be; Energy can be changed from one form to another, but it cannot be created or destroyed.
2. Energy can neither be created nor destroyed, but it can change from one form to another
Compare and contrast molds, casts, and trace fossils.
Compare and contrast molds and casts. Molds, casts, petrified fossils, carbon films and trace fossils. ... Mold is a hollow area in sediment in the shape of an organism and Cast a solid copy of an organism's shape formed when minerals seep into a hollow area.
Mold is a fungus that makes, multicellular filaments.
While cast fossils is when an animal dies and forms a cast fossil.
is the flavor of the new variety of pumpkin seeds as good as the flavor of the older varieties of pumpkin seeds
A new varieties of pumpkins that I am familiar with is the "naked bear".
The hullness seeds in this pumpkin are a good roasting seed. Whether you like a pumpkin seed is all a matter of personal taste.
Plz plz plz give me an answer
the ray box used as a source for light - because she changes the angle of light but not the source of light.
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which of the following is a cause of urbanization?
a. living in cities became more expensive than living in rural areas.
b. agricultural production became more efficient.
c. suburban homes became larger than urban homes.
d. paving over land changed the environment.
A more efficient agricultural production is a cause of urbanization (option b).
Urbanization can be defined as the process through which populations shift from rural to urban areas, thereby leading to a higher proportion of people that live in the city.When urbanization is not sustainable, it may exacerbate environmental problems that affect the quality of life of urban populations (e.g, poor air/water quality, waste disposal problems, water availability, etc).The principal causes of urbanization include:1. Industrial and manufacturing growth
2. More efficient agricultural systems/practices that reduce the employment in rural areas
3. Economic, political and social factors that lead to the migration of people to industrialized/urbanized areas
4. Modernization in the infrastructure of urbanized areas.
In conclusion, option b. agricultural production became more efficient, is one common cause of urbanization.
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Answer:
b. agricultural production became more efficient.
Explanation:
What type of air masses form at the poles and move toward the equator?
A. Polar
B. Maritime
C. Tropical
D. Continental
Polar air masses, which can be either cold and dry continental polar (cP) or cold and moist maritime polar (mP), form at the poles and move toward the equator. The correct answer is A. Polar.
Explanation:The type of air masses that form at the poles and move toward the equator are known as polar air masses. These are further subdivided into continental polar (cP) and maritime polar (mP) air masses. Continental polar air masses are cold and dry, forming over the landmasses in the polar regions, while maritime polar air masses form over the cold oceans and are cold but carry more moisture. The correct answer to the student's question is A. Polar.
What event must occur if a nucleus containing this molecule is to undergo mitotic cell division
The event that must occur if a nucleus containing this molecule is to undergo mitotic cell division is, that the bonds at point 3 break, and the molecules replicate.
What do you mean by Mitotic cell division?Mitotic cell division may be defined as a series of steps that involve the duplication of genetic content and other cell material to produce two daughter cells from a parental one.
Mitotic cell division always duplicates the cellular as well as genetic content and synthesizes two daughter cells, each accepting one copy of the doubled material.
Therefore, the event that must occur if a nucleus containing this molecule is to undergo mitotic cell division is, that the bonds at point 3 break, and the molecules replicate.
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To undergo mitotic cell division, DNA replication during the S phase is essential, followed by the breakdown of the nuclear envelope in prophase, arrangement and separation of chromatids in metaphase and anaphase, and nucleus reformation in telophase, culminating with cytokinesis.
Explanation:The event that must occur if a nucleus containing this molecule is to undergo mitotic cell division is the replication of DNA during the S phase of the cell cycle. This is crucial because, during mitosis, the replicated DNA needs to be evenly divided between two daughter cells to ensure each has a complete set of genetic instructions. The actual process of mitosis involves several key phases:
In prophase, the nuclear envelope breaks down and the nucleolus disappears, allowing access to the chromosomes.The mitotic spindle forms and the sister chromatids coil more tightly and become visible.During metaphase, sister chromatids align at the middle of the cell, and in anaphase, they separate and move to opposite poles.Finally, in telophase, the nucleus re-forms around the now separated chromosomes.Following mitosis, cytokinesis divides the cytoplasm, resulting in two genetically identical daughter cells.
Efficiency in the steps leading up the mitotic phase is facilitated by the G₂ phase, where cells prepare by synthesizing proteins necessary for chromosome manipulation and finalizing preparations for division.
Which best describes how the brain processes language?
Answer:
Speech and language brain regions. The visual cortex is the part of the cerebral cortex that is responsible for processing visual information. The auditory cortex in the cerebral cortex processes auditory information and as part of the sensory system for hearing, performs both basic and higher hearing functions.
Hi! This question is missing its options, so I went online to find them and I did. The complete question with its options is:
Which best describes how the brain processes language?
1. Wernicke's area is involved in hearing; Broca's area is used for speech.
2. Until children develop the facial muscles used for speaking, they are unable to communicate.
3. A single "Communication Center" handles both verbal and nonverbal language.
Answer:
The correct answer is option 1) Wernicke's area is involved in hearing; Broca's area is used for speech.
Explanation:
Language is an ability unique to humans that helps us understand each other and communicate our thoughts and feelings with our pairs.
There are two areas involved in language processing: Wernicke's area manages hearing and Broca's area is involved in speech.
Wernicke's area is located in the temporal lobe in the dominant cerebral hemisphere, more specifically in Brodmann area 22. It is responsible for language comprehension, whether it's spoken or written.
Broca's area is located in the frontal lobe of the dominant cerebral hemisphere, it occupies the pars opercularis and the pars triangularis, which correspond to Brodmann areas 44 and 45. Broca's area is linked to the production of language.
what effect would using a different restriction enzyme have in human gene engineering?
A restriction map is a map of known restriction sites within a sequence of DNA. Restriction mapping requires the use of restriction enzymes. In molecular biology, restriction maps are used as a reference to engineer plasmids or other relatively short pieces of DNA, and sometimes for longer genomic DNA ...
How are stem cells necessary for cell differentiation???
Stem cells are essential for cell differentiation due to their ability to divide and differentiate into various specialized cells, such as pluripotent human embryonic stem cells or multipotent stem cells in adult organs and tissues. During differentiation, stem cells express specific gene sets which determine their final cell type. Due to their capability, stem cells hold promising potential for treatments like cell-based therapy for various diseases.
Explanation:Stem cells are necessary for cell differentiation because they have the potential to divide and differentiate into various specialized cells. These include human embryonic stem cells (hESCs), which are pluripotent, multipotent adult stem cells found in organs like bone marrow and skin, stem cells from umbilical cord blood and baby teeth, and induced pluripotent stem cells (iPSCs) from adult stem cells.
Stem cells can differentiate into specialized cells when the physical and chemical growth conditions are altered. During differentiation, embryonic stem cells express specific sets of genes that determine their ultimate cell type. For instance, some cells in the ectoderm will express the unique gene for skin cells, thereby differentiating into epidermal cells. The differentiation process also relies on the signaling cascades of cells.
Overall, due to their capacity to differentiate into specialized cells, stem cells are considered vital potential treatment for diseases like diabetes and heart disease, where damaged or destroyed cells or tissues could be replaced using cell-based therapy, despite the myriad challenges that need to be resolved.
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A section of a chromosome that has genetic information for one trait
Final answer:
A gene is a section of a chromosome that codes for a specific trait, with alleles being different versions of these genes, leading to variation in the traits exhibited.
Explanation:
A section of a chromosome that contains genetic information for one trait is known as a gene. Genes are specific nucleotide segments located on chromosomes that code for proteins, which in turn determine our traits, such as hair color or blood type. Homologous chromosomes are pairs of chromosomes in a diploid organism that are the same length and have genes at the same locations or loci. However, different versions of a gene, called alleles, can exist and contribute to the variations observed in traits. For example, the gene for blood type has three different alleles: A, B, and O, and the combination of alleles inherited from our parents determines our blood type.