Answer:
(1) An asteroid struck Earth, altering the environmental conditions and leading to the extinction of many species, including dinosaurs.
Marsupial mole rats evolved in New Zealand in the 1700s and had few natural predators so they overpopulated the area. Scientist developed a virus to bring their numbers down, which was successful for awhile. After several generations though, their numbers began to increase. Why? *
A. Marsupial mole rats mated with other mole rats and created a new species.
B. Marsupial mole rats learned to survive regardless of being sick.
C. Some marsupial mole rats had a natural immunity to the virus.
d. Marsupial mole rats changed their reproductive cycle and were able to reproduce more.
Answer:
C. Some marsupial mole rats had a natural immunity to the virus.
Explanation:
According to Darwin's evolutionary theory, over time some of marsupial moles may have acquired natural immunity which evolves as an adaptive trait in the population. Since these organisms have more chance to survive and reproduce (survival of the fittest), they will likely transmit the natural immunity to the next generation .
When a deer hears a sound in the forest such as crackling footsteps it immediately freezes and bolts through the bushes this is an example of the. Response
Answer:
Conditioned response
Explanation:
When a stimulus is generated on the basis of learning behaviour of an individual then it is known as conditioned response. While unconditioned responses are produced naturally.
In this question, when the deer heard the crackling noise, he could relate it with the upcoming danger and hence in order to save himself he hides behind the bushes.
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Answer:
Silicates
Explanation:
Silicate minerals are the most common of Earth's minerals and include quartz, feldspar, mica, amphibole, pyroxene, and olivine.
The Law of Independent Assortment states
Answer:
that allele pairs separate during the formation of gametes. This means that traits are transmitted to offspring independently of one another.
Explanation:
Why does a coastal area have less variation in temperature than a noncoastal area?
Answer: Coastal areas have moderate temperature because the land absorbs and radiates heat much faster than sea. So, during the day cool air from sea rush towards the land and during night cool air from the land rush towards sea
Answer:
C
Explanation: Edge
Plasma is the ____________.
A) Fibers in blood
B) Matrix of blood
C) Cell that phagocytizes bacteria
D) Cell fragment found in the tissue
Answer:
matrix of blood
Explanation:
What is heat?
-
-
- please answer
Which is not part of the recipe for a thunderstorm to form?
O A. Unstable air
OB. A lifting force
O C. Moisture in the low atmosphere
O D. A cold front advancing
A cold front advancing is not part of the recipe for a thunderstorm to form.
How thunderstorms are formed ?
The same factors are required for each thunderstorm: lift, unstable air, and moisture. Oceans usually provide moisture. When warm, moist air is close to the ground and cold, dry air is above, unstable air forms. Lift comes from contrasts in air thickness. It raises unstable air, resulting in the formation of a large thunderstorm cloud.Commonplace wellspring of dampness for tempests are the seas. However, the amount of moisture that is added to the atmosphere is heavily influenced by the temperature of the water. Air is considered unstable if it continues to rise or sink when given a push. Warm, moist air near the surface and cold, dry air above indicate an unstable air mass.A piece of air or a bubble will continue to rise on its own in these circumstances if it is pushed upward. This parcel will cool as it rises, and some of the water vapor will condense, forming the typical thunderstorm's tall cumulonimbus cloud.Most of the time, in order for a thunderstorm to form, there needs to be something that pushes the air upward and starts the upward motion. Air density is the direct cause of this push upward.Different air densities result from the transfer of some of the sun's surface heating energy into the atmosphere. As the density decreases, the tendency for air to rise increases. The primary source of lift is this difference in air density, which can be achieved in a variety of ways.To know more about thunderstorms check this:
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In Florida, soapberry bugs have historically fed upon balloon vine fruits, which produce large fruits. Soapberry bugs that feed on these fruits have relatively long mouthparts. After the goldenrain tree was introduced as an ornamental plant in Florida, some populations of soapberry bugs became specialists and ate only goldenrain tree fruits, which produce small fruits. These specialized soapberry bug populations, on average, have shorter mouthparts than the populations that feed on balloon vine fruits. If a population of soapberry bugs from a balloon vine were experimentally moved to a goldenrain tree, what would you expect to happen over time?In your answer, include definitions of natural selection and evolution in your own words.
Answer:
It is expected that the introduced population decreases because they have a minor adaptive response to survive in this new environment in comparison to its competence (i.e., specialized populations of soapberry bugs).
Explanation:
Natural selection is represented by the evolutionary processes that will select for survival to those individuals with higher adaptive fitness, which in this case is represented by the ability to obtain resources (food). In concequence, and according to the evolution theory, these introduced individuals will have less chances to reproduce in order to perpetuate their genes in the next generation.
Why is it important to monitor the amount of nutrient available in freshwater ecosystems?
a
Too little nutrients available will limit the amount of producers and lead to smaller food chains
Too much nutrient available can lead to eutrophication and damage the ecosystem
Oь
A & B are both correct
d
None of the above are correct
Answer:
A & B are both correct
Explanation:
Too little nutrients available will limit the amount of producers and lead to smaller food chains because if you don't have enough nutrients to sustain producers, producers are backbone of foodchains hence not enough producers will survive and this will lead to smaller food chains.
Too much nutrient available can lead to eutrophication and damage the ecosystem, this is very true because if you have ever heard of algal blooms or seen like green layer covering large amounts of water, those areas are full of algaes and they are taking it alot of O2 in water thus depriving the organisms and plants nearby of O2 and essentially killing them.
Research and identify a vestigial structure of an organism of your choosing.
Why does the organism not need that structure anymore? (Think about what the structure's original purpose was.)
Answer:
The one of best example would be appendix in humans.
Explanation:
In the past, the appendix may have helped in the digestion of the plants by producing mucus and prevent any type of infection. Plants with a high content of cellulose are digested with the help of the appendix as reported.
It is not a part of the human digestive system and considers as a vestigial organ. Vestigial organs are the organs that are present in an organism with no particular function and their removal will not lead to any harm. Humans do not need it because our digestive system is more efficient and works better in the first stages of digestion than they used to.
Thus, the correct answer is - appendix in humans.
In flies dumpy wings and ebony bodies are each mutations recessive to wild type, and you expect them to behave in a Mendelian fashion. A dihybrid cross between two animals, each heterozygous for dumpy wings and ebony bodies (DdEe X DdEe) is performed with the following results:
Wild type wings; wild type body 473
Wild type wings; ebony body 156
Dumpy wings; wild type body 149
Dumpy wings; ebony body 52
You will ultimately explain these results using a Chi-squared test.
(a) Begin by setting up a Punnett Square to predict the phenotypic classes and ratios. Use the results of the Punnett square to form a hypothesis on phenotypic ratios.
(b) Perform the chi-squared analysis. Show work.
(c) What conclusion can be drawn from this analysis?
Answer:
See the answers below
Explanation:
Assuming that D (d) represents the allele for wing type and E (e) represents the allele for body type, crossing DdEe with DdEe will yield the following offspring according to the Punnet's square (see the attached image):
(a) 9/16 D_E_ wild type
3/16 D_ee wild wing, ebony body
3/16 ddE_ dumpy wing, wild body
1/16 ddee dumpy wing, ebony body
(b) Chi square [tex]X^2[/tex] = [tex]\frac{(O - E)^2}{E}[/tex], where O = observed frequency and E = expected frequency.
Phenotype O E [tex]X^2[/tex]
Wild type 473 9/16 x 830 = 466.875 [tex]\frac{(473 - 466.875)^2}{466.875}[/tex] = 0.08
wild w/ebony b 156 3/16 x 830 = 155.625 [tex]\frac{(156 - 155.625)^2}{155.625}[/tex] = 0.0009
Dumpy w/wild b 149 3/16 x 830 = 155.625 [tex]\frac{(149 - 155.625)^2}{155.625}[/tex] = 0.28
dumpy w/ebony b 52 1/16 x 830 = 51.875 [tex]\frac{(52 - 51.875)^2}{51.875}[/tex] = 0.0003
Total [tex]X^2[/tex] = 0.3612
Degree of freedom = 4 - 1 = 3
Tabulated value of [tex]X^2[/tex] (0.05)= 7.815
(c) Since the calculated Chi square value is less than the tabulated value, we conclude that the observed outcome agrees with the expected outcome and that the cross followed the standard Mendelian pattern.
(20 POINTS) Which statement BEST explains how RNA polymerase knows where to start & stop making an RNA copy of DNA?
-The enzyme proofreads each DNA strand to help ensure each molecule is copied exactly in the order of the original strand
-The enzyme binds to a sequence of nucleotides called introns they are cut out before they become functional
-The enzyme splices exons together before transcription begins to form the final mRNA molecule
-The enzyme only binds to regions of DNA known as promoters, which have specific base sequences
Answer:
The enzyme only binds to regions of DNA known as promoters, which have specific base sequences
What's the answer to this question? I need an explanation please.
Answer:
D.
Explanation:
Try it mate
Which groups of animals was The first land dweller
Answer:
dinosaurs
Explanation:
dinosaurs are the very first land dwellers and they lived very long
name 2 structures present in root hair cell that are not present in a red blood cell
Answer:
Root hair cells are alive and therefore need energy, which is why root hair cells contain many mitochondria in them. Root hair cells don't contain chloroplasts. Chloroplasts are used by the plant to make food using light energy. Since the roots aren't exposed to any form of light, they have no need for chloroplasts.
2 structures present in root hair cells are Cytoplasm and Cell membrane.
What does the cytoplasm do in a cell?
The cytoplasm is the gel-like fluid inside the cell. It is the medium for chemical reactions. It provides a platform upon which other organelles can operate within the cell. All of the functions for cell expansion, growth, and replication are carried out in the cytoplasm of a cell.
What are a cell membrane and its function?
The cell membrane, also called the plasma membrane, is found in all cells and separates the interior of the cell from the outside environment. The cell membrane consists of a lipid bilayer that is semipermeable. The cell membrane regulates the transport of materials entering and exiting the cell.
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You decide to perform a chromatin immunoprecipitation to see whether your favorite gene, the Cool gene, is associated with H3 histones that are methylated at lysine 9 (on the histone tail).
You then want to determine whether this methylation also means that expression of the Cool gene is inhibited in cells.
1. Which of the following techniques will allow you to answer this question?
O Northern blot
O DNA footprinting
O Yeast 2 Hybrid
O Quantitative RT-PCR
O Microaray
O Hybridization
Answer:
Quantitative RT-PCR
Explanation:
Reverse transcription polymerase chain reaction (RT-PCR), also known as quantitative Real-Time (RT) PCR, is a technique widely used in molecular biology laboratories in order to assess the expression level of target genes. This technique employs a transcriptase inverse that enables to obtain DNA from total RNA and then this total DNA is amplified as in a Polymerase Chain Reaction. The levels of the target genes are obtained by comparing their relative expression with one or more control genes.
Explain how the boss at the company in the following scenario could have delegated the tasks more appropriately : Samuel and Martha work at the same agricultural consultation company . Samuel works in agricultural quality control, while Martha is an agricultural logistics specialist . A new boss delegated Martha to negotiate a financial deal with a farm and then create a strategy for the farm.
Answer:
The new boss take the right decision.
Explanation:
The new boss sent Martha to the farm for the financial deal and strategy for the farm is the right choice because Martha is a specialist in agricultural logistics which has good management skill that is required by the task in the farm. Samuel is not a good choice for sending him to the farm because he works in agricultural quality control which is different from the job of Martha.
How old is the earth
Answer:
4.543 billion years old
Explanation:
The replication of DNA is a complicated process during which DNA is occasionally damage. Discuss when in the cell cycle DNA is assessed for damage and predict what effect DNA damage would have on the cell cycle.
Answer:
DNA is first checked during the G1/S. This is when the integrity of DNA is checked to make sure it's correct and ready to be replicated in the S phase. If the DNA fails the check, it can leave the cell cycle or enter a resting phase called G0, where it stays until the DNA is corrected. Any damage is fixed by proteins, the key one being the p53 protein, a tumor suppressor. It works by halting the cell cycle and activating repair proteins. If the damage is irreparable, it initiates apoptosis, programmed cell death, to prevent the damaged DNA from replicating and dividing into cells. If this gene is missing or mutated, damaged cells continue to replicated rapidly and lead to the rise of tumors and thus cancer. If nothing is wrong or the errors are fixed, the G1/S checkpoint gives the green light, to allow DNA to replicate. The now replicated chromosomes are once again checked in the G2 checkpoint. Here, they're checked again for integrity and whether or not replication occurred correctly. If the DNA fails these checks, the cell once again attempts to fix the problems. If these problems aren't corrected due to mutations in the repair proteins, the cells containing the damaged chromosomes will continue to replicate rapidly and cause cancer. Should no problems occur, cyclin dependent kinases (CDKs) are activated and allow the cell to continue into mitosis. DNA damage can basically lead to the rapid division of mutated cells and cancer.
Picture the morphology of an average soapberry bug from a rain tree population and compare it to the morphology of its new food source, balloon vine seeds. This average bug was taken from a population containing a range of sizes. (a) Are large, small or average bugs more likely to have relative fitness on the new food source?(b) List one change in bug morphology that you would reasonably expect in bug populations that have been living on golden rain trees. (c) List one change in behavior that you would reasonably expect in bug populations that have been living on golden rain trees.(d) Soapberry bugs are small relative to their host plants, and the bugs vary in their abilities to disperse. Although they have wings, many soapberry bugs have developed flight muscles and walk more often than they fly. In davis, where both balloon vines and golden rain trees are grown, would a dispersing bug likely have higher fitness than one with less developed flight muscles? Explain your answer.
Answer:
(a) In this case, small bugs are more likely to have relative fitness on the new food source.
(b) A change that will occur in bug morphology is that the female bugs will turn out to be the same size as the male bugs.
(c) In terms of behavior, the bugs will experience less competition towards reproducing early.
(d) Yes, the dispersing bug would have higher fitness as they will be able to easily get access to new resources once the previous one has run out, whereas the bugs with less developed fight muscles will not be able to do so.
Hope that answers the question, have a great day!
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Write the least common multiple of 7 and 14
does the amount of bacteria change After conjugation?
Answer: yea it does
Explanation:
conjugation (prokaryotes) Conjugation is the process by which one bacterium transfers genetic material to another through direct contact. During conjugation, one bacterium serves as the donor of the genetic material, and the other serves as the recipient.
An ecosystem has many levels of organization. Which level will have the most individuals?
Answer:
Community
Explanation:
A community is all the biotic factors of an ecosystem. There are many populations of different species within an area. These populations in one area is a community. A community and its abiotic features is a ecosystem. Therefore, communities have the most individuals in an ecosystem.
A single prokaryotic call can divide several times in an hour.most eukaryotic cells cannot divide this quickly?
Answer:
D
Explanation:
Eukaryotic cells are more structurally complex than prokaryotic cells.
hope it helps!
describe 3 characteristics of life that archea bacteria have
methanogens, halophiles, and thermophiles. The methanogens are anaerobic bacteria that produce methane. They are found in sewage treatment plants, bogs, and the intestinal tracts of ruminants.
What is one of the functions of the nucleus?
A.
to contain the genetic information of an organism
B.
to remove waste products from a cell
C.
to provide structural support for a plant cell
D.
to determine what materials can enter or leave a cell
Answer:
A
Can i get brainliest plz
Explanation:
Answer:
i believe it is B i do not exactly remember
Explanation:
Alonte is viewing a cell under a microscope.
The presence of which of the following cell structures would tell him that the cell is eukaryotic?
Choose 1 answer:
Ribosomes
Cytoplasm
Nucleus
DNA
Answer:
DNA
Explanation:
you can tell if the DNA is within the nucleus in the cell then it is eukaryotic but if the DNA is free floating in the cell then it's prokaryotic
Answer:
Nucleus
Explanation:
Only eukaryotes have a membrane-bound nucleus, which directs cellular functions and stores genetic information
A lethargic 22-month old black female was presented by her mother to the emergency room at 2:15 am on a Sunday. The child had a history of a runny nose, hoarse cough and low-grade fever (~99F) for the past 48 hours. The mother was concerned about the forced and noisy breathing of the child. The pediatrician examined the child and found cloudy eyes and mild inflammation of the ears, but no overt signs of bacterial infection (no significant changes in the eardrums). The throat of the child was red and coated with mucus. The larynx was swollen and raw.
The physician performed a rapid Strep Test*, and found it was negative. Throat swabs were taken for culture. The physician placed the child in a room with a warm vaponzer for about 30 minutes. This dramatically improved the breathing of the child.
rapid Strep test* is used in the diagnosis of bacterial pharyngitis caused by group A streptococci (GAS), sometimes termed strep throat.
Questions:
1. What is the presumptive diagnosis for this case?
2. Will the throat cultures likely show evidence of Streptococcus pyogenes? How about Staphylococcus aureus?
3. Do you believe that this is a bacterial or viral disease? Why?
4. What further treatment might be indicated for this case?
Answer:
it is adenoviral pharyngitis, croup
No, due to the fact that the the Strep test was negative and the overall picture indicates a viral infection
it is a viral disease; this viral disease is characterized by little or no pus on pharynx, a good response to warm vapor to clear congestion
further treatment that is needed in this case is a more vapor treatment, decongestant, and analgesic; antibiotics should be reserved unless Strep of Hib shows on culture.
Explanation:
adenoviral pharyngitis,symptoms are usually, cough, fever, cough, sore throat e.t.c..
croup, known as laryngotracheobronchitis also is a viral respiratory infection which causes swelling inside the trachea, that hinders normal breathing process and symptoms include cough, stridor, and a hoarse voice.
help me with this _XX
Answer:
B. Hardness
Explanation:
Physical properties of a substance is defined as the properties which can be observed or measured without changing the composition of matter.
Physical properties include odor, appearance, color, texture, boiling point, melting point and many others.
Hardness is a physical property of a substance as it describes the resistance of substance to deformation and can be observed by simple touch or without changing the composition of matter.
While reactivity, toxicity and flammability are chemical properties of substances that change one type of matter into another type.
Hence, the correct option is B.