Answer:
a. The particular set of resources a species uses
Explanation:
A niche is described as the interaction of an individual with its environment. It is a functional position of an individual. The niche includes how an organism lives, its behavior and abiotic factors such as light, temperature, climate etc.The ecological niche is a multidimensional thought which includes the role of an individual like predation, mutualism, parasitism, competition etc. An example of niche; A bird lives on a tree and eat the fruits.
What happens to the bronchioles in an asthma attack? How do regular rescue inhalers treat asthma? (i.e. bronchodilators). How do steroids treat asthma symptoms in the long term (HINT: they are NOT rescue inhalers)
Answer:
Asthma refers to a disease in which swelling of the airways results in the restriction of airflow into and out of the lungs. During the occurrence of an asthma attack, the production of the mucus gets increased, the bronchial tree muscles become constricted, and the inflammation of the air passages lining occurs. This further minimizes the flow of air and generates a kind of wheezing sound.
The bronchodilators quickly help in relieving the symptoms of acute asthma by opening the airways. The activity of inhaled bronchodilator begins some minutes post inhalation and endures for two to four hours.
All the kinds of steroids minimize swelling in the airways, which transports air towards the lungs and minimize the generation of mucus produced by the bronchial tubes. This makes one breathe easily.
The inhaled steroids cure swelling of the airways, and only a very minute concentration of it gets captivated by the body. Thus, these medicines do not seem to result in any kind of serious side effects in a long run.
Explain how mitotic recombination leads to the mosaic condition termed twin spots.
Answer:
If an individual Drosophila has two or more populations of cells comprising different genotypes from one single egg then it is termed as twin spots or mosaic.
Explanation:
There might be different reasons for mosaic to occur like
Nondisjunctioning of the chromosomes
Lag in anaphase
Endoreplication
Mutations in a single cell
Mitotic recombination:
One of the major ways through which mosaic or twin spots arise is the mitotic recombination. It is also termed as somatic cross over. Twin spot or mosaic generally occurs if there is linking of heterozygous genes in repulsion. The recombination generally happens among the centromeres from the adjacent genes.
A common example of the mitotic recombination is the Bloom's syndrome. Bloom's syndrome is caused due to the mutation that occurs in the blm gene. As a result, there are defects in the BLM protein produced.
Define virus and virion, and describe the parts of a virion.
Answer:
A virus is a tiny infectious biological agent that can only replicate or duplicate inside the host cell. These infectious agents can infect all different types of living organisms ranging from animals and plants to microorganisms and archaea and bacteria.
Virions are ineffective particle or form of the virus outside of the host cell, with RNA or DNA and a protein capsid.
The main role of these infectious agent virions is to transfer the DNA or RNA genome from itself to the cell of host and expressed the gene which means produce proteins from the genome transferred to the host cell.
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.
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.
Define mutagen and describe how mutagens are used in genetic research.
A mutagen is a physical or chemical agent that permanently changes genetic material, usually DNA, in an organism and increases the frequency of mutations. Mutagens are used in genetic research to induce mutations and study their effects on organisms.
Explanation:A mutagen is a physical or chemical agent that permanently changes genetic material, usually DNA, in an organism and increases the frequency of mutations above the natural background level. Mutagens are used in genetic research to induce mutations and study the effects of these mutations on organisms. They are used to investigate gene function, understand the causes of genetic diseases, study the mechanisms of evolution, and develop new treatments for diseases.
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.
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).
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 branch of biology concerned with identifying, naming, and classifying all living things is taxonomy.
a. True
b. False
Answer:
True.
Explanation:
Taxonomy may be defined as one of the main branch of biology that helps in the classification of organisms. The organisms are classified on the basis of similarities and differences among them.
Taxonomy includes the identification of an individual by looking at its morphological characters. The nomenclature ( naming of organism) and its classification in to different groups.
Thus, the correct answer is option (a).
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
What might be a use for fluorescence in situ hybridization (FISH)?
a. For identification of a specific gene in a DNA extraction by hybridization to a DNA probe
b. For identification of a specific gene by hybridization to a DNA probe within live cells that have had their DNA denatured by heat.
c. For identification of an mRNA within an RNA extraction by hybridization to a DNA probe.
d. For identification of both mRNA and DNA in cellular extracts using an RNA probe
e. None of the above
Answer:
B.
Explanation:
Flourescent insitu hybridization-This technique permits the direct analysis of sequences of DNA or RNA in tissues
-Through this technique various chromosomal abnormalities can be determined as it focuses on that part of the DNA for which a complementary probe has been used.
-The method involves the denaturation of DNA in a tissue section followed by the application of a labeled probe which is complementary to the sequence of interest.
A woman comes to your genetic counseling center because she knows that Huntington disease occurs in members of her family. Her paternal grandfather was afflicted, but so far her father shows no symptoms. Her two great-great grandmothers on her father's side were healthy well into their 90s, and one of her great-great grandfathers died of unknown causes at 45. Testing for Huntington disease is extremely expensive, but she is concerned that she may fall victim to this disease and wants to plan her life accordingly. After examining her pedigree you advise her to A. not get tested because there is no possibility that she is homozygous. B. not get tested because only males in her family get the disease. C. get tested because her father could be a carrier. D. not get tested because her father is only a carrier and it is very unlikely her mother is a carrier. E. not get tested because her 40-year-old father shows no symptoms.
Answer:
C. Get tested because her father could be a carrier
Explanation:
As Huntington Disease is an inherited dominant disease, it means that is enough the presence of one allele to develop illness. Her paternal grandfather was affected but not her father great-great grandmothers. Is her father, carrier of an HD allele? The problem here is that we can’t be sure her father is not a carrier, because although he’s 40 years old and doesn’t show symptoms of illness, HD uses to appear between 30 to 50 year old ages, but it can appear at any age. Eventually a possibility for the disease to appear, is still possible.
Q:- Short hair rabbit is goverened by a dominant gene (L)
andlong hair by its recessive alleles (l). Black hair results from
theaction of the dominant genotype (B) and brown from therecessive
genotype (b).
A. In cross between dihybrid short ,black and homozygousshort,
brown rabbits, what genotypic and phenotypic ratios areexpected
among their progeny?
B. Determine the expected genotypic and phenotypic ratios
inprogeny from cross LlBb*Llbb.
Answer:
A) he phenotypic ratio is
short & black : short & brown
8:8
1:1
Genotypic Ratio is
LLBb : LLbb: LlBb : Llbb
4:4:4:4
1:1:1:1
B)
Genotypic Ration
LLBb : LLbb: LlBb: Llbb: llBb: llbb
2: 2: 4: 4: 2:2
1:1:2:2:1:1
Phenotypic ratio
Short & Black : Short & brown: Long & black : Long & brown
6: 6: 2: 2
3:3:1:1
Explanation:
Given -
Allele for short hair (L) is dominant over long hair allele (l)
And Black hair allele (B) is dominant over brown hair allele (b)
A) Genotype for dihybrid short and black rabbit is LlBb
Genotype for homozygous short and brown rabbits is LLbb
Cross between LlBb and LLbb will result into following offspring
LB Lb lB lb
Lb LLBb LLbb LlBb Llbb
Lb LLBb LLbb LlBb Llbb
Lb LLBb LLbb LlBb Llbb
Lb LLBb LLbb LlBb Llbb
Hence, the phenotypic ratio is
short & black : short & brown
8:8
1:1
Genotypic Ratio is
LLBb : LLbb: LlBb : Llbb
4:4:4:4
1:1:1:1
B) LlBb*Llbb.
LB Lb lB lb
Lb LLBb LLbb LlBb Llbb
Lb LLBb LLbb LlBb Llbb
lb LlBb Llbb llBb llbb
lb LlBb Llbb llBb llbb
Genotypic Ration
LLBb : LLbb: LlBb: Llbb: llBb: llbb
2: 2: 4: 4: 2:2
1:1:2:2:1:1
Phenotypic ratio
Short & Black : Short & brown: Long & black : Long & brown
6: 6: 2: 2
3:3:1:1
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 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
Inhibin secreted by granulosa cells selectively inhibits secretion of FSH by the pituitary
a. True
b. False
Answer:
The correct answer will be option-true.
Explanation:
Follicular stimulatory hormone or FSH and inhibin are the complex proteins which play a various biological role in the reproductive system.
The FSH stimulates the secretion of inhibin from the gonads in both males (Sertoli cells) and females (granulosa layer). The production of inhibin suppresses the secretion of FSH from the pituitary gland.
The suppression of FSH directly suppresses the secretion of further inhibin and thus, option-true is the correct answer.
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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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.
Biologists think that endosymbiosis gave rise to mitochondria before plastids partly because
a. the products of photosynthesis could not be metabolized without mitochondrial enzymes.
b. all eukaryotes have mitochondria (or their remnants), whereas many eukaryotes do not have plastids.
c. mitochondrial DNA is less similar to prokaryotic DNA than is plastid DNA.
d. without mitochondrial CO2 production, photosynthesis could not occur.
Answer:
b. all eukaryotes have mitochondria (or their remnants), whereas many eukaryotes do not have plastids.
Explanation:
It is a fact that among eukaryotes, all the reresentatives of the Domain (Eukarya) have mitochondria (more or less modified) but not all of them posses plastids.
Indeed, only a selected group of eukaryotes have acquired plastids. This group includes the autothropic algae (e.g. green algae or Chlorophytes, red algae or Rodophytes, brown algae or Phaeophyceae, etc), briophytes, and traqueophytes (vascular plants, pteridophytes, conifers and flowering plants). The endosymbiotic event that led to the formation of a plant cell initially involved an eukaryotic heterotrophic cell (that already had mitochondria and nucleus) which phagocyted a cyanobacterium. Over time, this cyanobacterium transformed into the plant cell's plastid.
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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Smooth muscles of the digestive system move food by the process of peristalsis.
a. True
b. False
Answer:A
Explanation:
Answer: A. True
Explanation: "Peristalsis. Peristalsis is a series of muscular contractions that propel food through the small intestine. These kinds of controls help you get the most nutrients out of your food. ... This coordinated contraction of smooth muscle keeps food moving on its one-way path through your digestive system."
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.
What binds to a stop codon on a mRNA during translation?
a. transcription factor
b. tRNA
c. termination factor
d. transcription initiator
Answer:
Termination factor.
Explanation:
Translation may be defined as the process of formation of the protein from the RNA molecule y the help of enzymes and translation factors. The translation occurs in 5' to 3' direction.
The three main steps of the translation are initiation, elongation and termination. The release factors or translation termination factors binds to the stop codons and results in the translation termination. Prokaryotes release factors include RF1, RF2, and RF3 that binds to the stop codons.
Thus, the correct answer is option (c).
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.
(5th grade science)
In each set, circle the item in the group that doesn’t belong. Justify your reasoning
1.) consumer
Producer
Predator
Prey
2.) mouse
Snake
Mushroom
Lion
3.) Decomposers
Animals
Plants
Sunlight
Answer:
2. Mushroom 3. Sunlight
Explanation:
2. A mushroom is a fungus not an animal
3. Sunlight is not alive animals, plants, and decomposes are.
Plant species A has a diploid chromosome number of 12. Plant species B has a diploid number of 16. A new species, C, arises as an allopolyploid from A and B. The diploid number for species C would probably be
a. 14. b. 16. c. 28. d. 56.
Answer:
c. 28
Explanation:
Plant A has a dipoid chromosome number of 12, so its gametes will have an haploid number of 6 chromosomes.
Plant B has a dipoid chromosome number of 16, so its gametes will have an haploid number of 8 chromosomes.
Plant A Plant B2n = 12 2n = 16 n = 6 n = 8The new species C arises as an allopolyploid from A and B. An allopolyploid usually originates from the breeding of two different species.
In this case, a gamete from plant A combines with a gamete from plant B to form a hybrid with 14 chromosomes (6 from A and 8 from B). These chromosomes are unpaired, so the hybrid is sterile.
In order to become a fertile diploid individual of species C, the most common mechanism is polyploidization, where the genome duplicates. That way, the resulting plant C has a diploid number of 14 x 2 = 28 chromosomes, of which 12 are A and 16 are B.
Species C, being an allopolyploid of species A and B, would likely have a diploid number that is the sum of the diploid numbers of species A and B. In this case, that is 28.
Explanation:The new species C, being an allopolyploid of species A and B, is formed by a combination of the whole sets of chromosomes from both species A and B. Thus, we would add together the diploid numbers of both species to determine the diploid number of species C. Plant species A has a diploid chromosome number of 12 and plant species B has a diploid number of 16. Adding these together gives us a total diploid number of 28. Therefore, the correct answer would be option c. 28.
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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.
Why does each replication fork require both leading and lagging strand synthesis?
Select the 2 reasons below.
A) Because DNA synthesis is semi-conservative.
B) Because DNA polymerases must synthesize DNA 3' to 5'.
C) Because the DNA templates are antiparellel.
D) Because DNA polymerase only synthesizes DNA in one direction.
Describe the characteristics of the garden pea that made it a good organism for Mendel's analysis of the basic principles of inheritance. Evaluate how easy or difficult it would be to make a similar study of inheritance in humans by considering the same attributes you described for the pea.
Answer and explanation:
The garden pea had many advantages to be used as a model in inheritance studies. These plants grow very fast, so you can rise several generations in little time. This fundamental if you want to do this kind of studies. The study object needs to have a brief generational time, so they can be selected and their descendants can be raised again. Another advantage was that garden peas can be raised easily. They don't need any special care. Besides, they were common in the market. Mendel could find them and bought them any time that he wants. Also, they presented visible characteristics that could vary from one plant to another. Some pea gardens had violet flowers, while others had white flowers. Some were tall, while others were small. These made possible to select plants with specifics features and to study if they could transmit these features to the next generations.
It could be really difficult to do the same experiment in humans. several years would have to pass to observe new generations, so during the lapse time of the researcher, only a few human’s generations could be studied.