You place a centrosome in a test tube that is a square plastic box the size of a cell. You add tubulin and GTP so that microtubules can be nucleated by the centrosome and be assembled in vitro. You initially place the centrosome in the lower right corner of your test tube box. Once microtubules have assembled to steady state where will your centrosome be located?
a) In the upper right corner of your test tube box
b) In the upper left corner of your test tube box
c) In the center of your test tube box
d) In the lower left corner of your test tube box
e) In the lower right corner of your test tube box

Answer& explanation:

The mechanism of action of chloramphenicol can be explained as follows:

Chloramphenicol binds to the 50S subunit of the ribosome, inhibiting the protein synthesis of the bacteria, thus having bacteriostatic action (inhibiting the growth of bacteria, preventing their proliferation).

In addition, chloramphenicol can be bactericidal (destroys bacteria) when in high concentrations, or when used against highly sensitive microorganisms, such as Haemophilus influenzae and Streptococcus pneumoniae. The mechanism of action for these bacteria, however, is not yet elucidated.

Answer:

Adaptive radiation

Explanation:

Adaptive radiation occurs when an ancestral species move to a new environment that has various resources that are necessary for survival and also has environmental conditions that would ensure its offspring adapt well over time. In this new environment, the ancestral species would produce offspring with different traits and behaviors that will allow them to survive in this new environment while occupying their various niches. Over a relatively short time, different species arising from the common ancestor would occupy the new environment.

Anaphylactic shock, a severe and life-threatening allergic reaction, is most often caused by peanuts, milk, and shellfish.

Anaphylactic shock is a life-threatening allergic reaction that can occur when a person with a food allergy is exposed to the allergen. The most common food allergens that can trigger anaphylaxis are peanuts, milk, and shellfish. These foods contain proteins that can elicit an immune response in individuals with allergies, leading to symptoms such as difficulty breathing, rapid pulse, and decreased blood pressure.

https://brainly.com/question/32657070

#SPJ3

Anaphylactic shock is most often caused by peanuts, milk, and shellfish, triggering a rapid immune response and severe symptoms. Epinephrine is used to counteract the effects of anaphylaxis.

Anaphylactic shock, a life-threatening food allergy reaction, is most often caused by peanuts, milk, and shellfish.

When an individual with a severe allergy consumes or comes into contact with these allergens, it triggers a rapid immune response. This immune response leads to the release of histamine and other chemicals, causing symptoms such as swelling, difficulty breathing, and a drop in blood pressure.

Epinephrine is used to counteract the effects of anaphylaxis and can be life-saving. It is important for individuals with known severe allergies to carry automatic epinephrine injectors at all times.

https://brainly.com/question/38999011

#SPJ6

Answer:

The answer is letter B. Eumetazoa and Lophotrochozoa

Explanation:

Eumetazoa and Lophotrochozoa

Because the phylum Cycliophora neither helps or harms its lobster host.

Answer:

c. 40%

Explanation:

DNA is composed of smaller subunits called nucleotides.

Structure of a  nucleotide contains a  5-carbon sugar (Deoxyribose), phosphate group and one of the four nitrogenous bases.

Adenine and Thymine are nitrogenous bases found in DNA. Other nitrogenous bases are cytosine, guanine and uracil.

Adenine, Thymine, Guanine and Cytosine are found in DNA whereas in RNA, Uracil is present instead of Thymine.

DNA is a double stranded structure.

In DNA, adenine of one strand always pairs with thymine of the other strand (complementary). Similarly, guanine of one strand pairs with cytosine of complementary strand. Adenine pairs with Thymine via 2 hydrogen bonds whereas cytosine pairs with guanine via 3 hydrogen bonds. This hydrogen bonding maintains the double helix structure of DNA.

It is implied that for every thymine present in DNA there will be adenine on the complementary stand with which it will bind via 2 hydrogen bonds.

So if a double stranded DNA sample contains 10% Thymine, then it will also contain 10% adenine. This makes the combined contribution of adenine and thymine to be 20%. The left over 80% of DNA will contain equal amounts of cytosine and guanine as each guanine binds with cytosine via 3 hydrogen bonds. So if we divide 80% into 2 equal parts then it is 40%. Hence, there is 40% guanine, 40% cytosine, 10% adenine and 10% thymine.

The percentage of guanine in a double-stranded DNA sample with 10% thymine is 40%, due to base pairing rules where adenine equals thymine and guanine equals cytosine.

The question is focused on understanding the relationship between the different nucleotide bases in a DNA molecule. According to Chargaff's rules, the amount of adenine (A) is equal to thymine (T), and the amount of guanine (G) is equal to cytosine (C). Given that the DNA sample is composed of 10% thymine, it follows that it must also be composed of 10% adenine since A pairs with T. Therefore, since adenine and thymine together make up 20% of the DNA bases (10% + 10%), and the total amount of DNA bases must equal 100%, the remaining 80% of the bases are guanine and cytosine. Because guanine pairs with cytosine, their percentages must be equal. So, guanine and cytosine will each account for half of the remaining 80%, which is 40%. Thus, the percentage of guanine in this DNA sample is 40%.

Answer:

Unique phylogenetic lineages. (Ans. B)

Explanation:

Biodiversity: It is defined as the total species or variety of species present in a place on earth. This variety common measurement is known as species richness, it is defined as the count of species present in an area.

It is helping in to measure variation at the species, genetic, and ecosystem level. Phylogenetic lineage showing the relationship (evolutionary) between different biological species. Their phylogeny is determined by the differences and similarities in their genetic characters.

''Unique phylogenetic lineages.'' is the correct answer.

Biodiversity is the total number of species that are present in a place.

Biodiversity helps in the measuring of variation at the species, genetic, and ecosystem level. Phylogenetic lineage shows the relationship between different biological species so we can conclude that ''Unique phylogenetic lineages.'' is the right statement.

Learn more about biodiversity here: https://brainly.com/question/11542363

Answer:

NADH and FADH2

Explanation:

Oxidative phosphorylation is the last step of cellular respiration involving two smaller steps; Electron transport chain (ETC) and chemiosmosis.

ETC is a series of proteins and organic molecules present in the cristae of the mitochondria. Electrons are passed from one member of the transport chain to another in a series of reduction-oxidation reactions (redox). Energy released is captured as a proton gradient.

All the electrons that are supplied into the transport chain are donated by NADH and FADH2 molecules (reduced electron carriers) produced in the previous stages of respiration. As the electrons are passed down the chain, they move from a higher to a lower energy level, releasing energy in the process. The released energy is used by several of the protein complexes to pump protons from the matrix of the mitochondria to the intermembrane space, forming a proton gradient.

The electrons donated by NADH are at a higher energy level i.e. NADH is a very good donor of electrons in redox reactions. This attribute allows NADH to transfer its electrons directly to Complex I, where energy is released and the complex uses this energy to pump protons across the membrane.

FADH2, on the other hand, is not a good donor of electrons. Thus, its electrons are at a lower energy level, making it unable to transfer its electrons to ComplexI. It feeds them through Complex II instead, which does not pump protons across the membrane.

This factor (Complex I bypass) causes FADH2 molecules to contribute less to the proton gradient than NADH molecules.

N.B: the energy stored in the proton gradient is subsequently used to produce ATP in Chemiosmosis.

Final answer:

In the electron transport chain part of oxidative phosphorylation, the molecules NADH and [tex]FADH_2[/tex] donate high-energy electrons to power the protein complexes and create ATP. These electron carriers are produced during earlier steps of cellular respiration.

Explanation:

Oxidative phosphorylation is the third and final step of aerobic cellular respiration and it includes two processes: the electron transport chain (ETC) and chemiosmosis. In the ETC, energy is provided by two molecules, NADH and [tex]FADH_2[/tex], which are the reduced forms of the electron carriers NAD+ and FAD.

These molecules are produced during earlier stages of cellular respiration and donate their high-energy electrons to power the protein complexes within the ETC. As the electrons flow through the chain, they release energy used to pump protons across the mitochondrial membrane, creating an electrochemical gradient.

During chemiosmosis, the accumulated protons flow back into the mitochondrial matrix through an enzyme called ATP synthase, which synthesizes ATP from ADP and inorganic phosphate. The flow of protons provides the energy necessary for ATP production, culminating in the highly efficient generation of ATP, essential for cellular processes.

Answer: option D

Reclamation of sanitary landfills occurs before the land fills is capped.

Explanation:

Reclamation of sanitary landfills is a method use to expand the municipal solid wastes sanitary landfill capacity so as to avoid high cost of purchasing another land.

Sanitary landfills is an area of land where wastes is allow to decompose or degraded chemically, physically and biologically until it is safe.

This reclamation is done before the landfills is capped so as to avoid high cost of getting another land.

Answer:

The right answer is D) D and E

Explanation:

All the organisms are classified into seven major groups or there are seven levels of classification in which organisms are divided. These are Kingdom, phylum, class, order, family, genus, and species.

So here kingdom is the highest level of classification and species is the lowest level of classification. So as we move from kingdom towards species the homology increase and if we move from lower to higher level the homology between organism decreases.

So as the order is at the lower level than class therefore organisms in class will show the greatest degree of structural homology therefore D and E would be expected to show higher structural homology.

Answer:

Option A

Explanation:

Undigested fats include all those fatty acid and lipids which do not have the ability to dissolve in water. This inability makes them difficult elements for digestion. All this undigested fat accumulates and reaches the intestine for digestion as globs. Globs are emulsified by the bile salts and are broken down into smaller fat droplets. The smaller fat droplets have large surface area and hence now they can be acted upon by the fat-digesting enzyme pancreatic lipase. Thus, the first set of enzymes that act upon the undigested fats in the intestine are pancreatic lipase

Hence, option A is correct

The enzymes that digest the majority of ingested fat are pancreatic lipases.

The enzyme group that digests the majority of ingested fat is pancreatic lipases. These enzymes are produced and secreted by the pancreas and work primarily in the small intestine, where they break down dietary fats into simpler compounds like fatty acids and glycerol. This is an essential part of the digestion and absorption process for fats in our diet. The option pepsin and stomach acid refers to the digestion of proteins in the stomach, while bile salts are produced in the liver and help to emulsify fats, preparing them for digestion by lipases. The lingual lipases, meanwhile, are secreted by the salivary glands and start the digestion of fats in the mouth, but their contribution to overall fat digestion is relatively minor.

https://brainly.com/question/33448886

#SPJ6

Answer:

This is example of Inactivation of X chromosome.

Explanation:

In calico cats, Fur color is carried on Chromosome X. Female cats have two X chromosomes. When they have two X chromosomes, some of these X chromosomes in some cells throughout the body are INACTIVATED and they are seen as black dots under microscope. These black dots are called Barr Bodies. Normally calico cats have brown and white fur color, and also black color due to this barr bodies. X in activation or the formation of barr bodies are not observed in males because they have only one X chromosome.

Answer:

d. directional selection

Explanation:

Directional selection is a form of natural selection that occurs when a particular extreme phenotype of a species is highly favored and thrives more than the other extreme phenotype. This is particularly influenced by environmental changes resulting in differences in the survival between both extreme phenotypes.

In the Galapagos Islands during drought, the seeds to be fed on by finches are mostly large in size, giving rise to the survival of only finches with large beak size of 9 mm to 10 mm as against finches with small beak size. Finches with large beak sizes are favored over  finches with phenotypic traits of small beak sizes.

Answer:

1st trophic level

Explanation:

Trophic levels are each of the sets of organisms in an ecosystem that obtain matter and energy in the same way, so they occupy an equivalent place in the food chain.

The energy that living beings need to perform vital functions (nutrition, relationship and reproduction) comes from the Sun. Plants are responsible, through photosynthesis, for transforming inorganic matter into organic. This matter and energy will pass to the rest of the organisms in the ecosystem, such as herbivorous and carnivorous animals. Finally, the decomposing organisms will be responsible for breaking down this organic matter into inorganic, closing the cycle so that it can be restarted.

Therefore, we can distinguish three trophic levels:

-  Producing organizations (autotrophs) or 1st trophic level

- Consumer organisms (herbivores, carnivores, scavengers).

- Decomposing and transforming organisms (break down organic matter into inorganic).

Producing organisms are autotrophs (plants, algae and some bacteria). They are capable of manufacturing their own organic matter from inorganic matter (water, mineral salts and carbon dioxide) and the energy of the sun, which is why they are called producers.

Producing organisms constitute the lowest trophic level, being the basis on which the higher levels are based. They are the only ones that, through photosynthesis, are capable of capturing solar energy and transforming it into chemical energy. They are also the ones that generate the greatest amount of dead organic matter in the ecosystem.

Answer:

Haploid: Haploid is the quality of a cell or organism having a single set of chromosomes. A haploid cell only has one set of chromosomes, and most of the time that refers to the sex cells, either eggs or sperm.

Diploid: Most animal cells and plant cells are diploid. The reason they're diploid is because they got one chromosome from their mother and one chromosome from their father. "Di" means two, of course.

Explanation:

There is a critical transition from a diploid cell to a haploid cell to allow normal reproduction to occur, so that when these two haploid cells come together with a single set of genetic information, they can come together into a zygote (made of when the egg cell and the sperm cell come together) that then reconstitutes a diploid cell, which can then become a new individual.

I don't know much about biology and stuff, but I hope the notes from my notebook help. Good luck!

Answer: Diploid cells contain two comlete sets of chromosomes and haploid only contain half.

Explanation:

Answer:

The correct answer is "Mutate or remove the Shine-Dalgarno sequence on the mRNA".

Explanation:

The Shine-Delgarno sequence is a fragment of bacterial and archaeal messenger RNA that helps to recruit the messenger RNA to the ribosome to initiate protein synthesis by translation. Mutating  or removing the Shine-Dalgarno sequence on the mRNA will prevent translation of a particular prokaryotic mRNA. Therefore, this is a reasonable experimental strategy to achieve this effect without targeting the ribosome, but the prokaryotic mRNA.

Answer:

Rr

Explanation:

This cross is a typical example of a test cross. A test cross is a cross between a heterozygous F1 progeny (different alleles) and a homozygous recessive parent in order to determine the actual genotype of the dominant parent i.e. whether homozygous or heterozygous dominance. In a test cross, if any of the offsprings show a recessive phenotype, it means the dominant parent is heterozygous

In this case, the allele for smooth pea (R) is dominant over that of wrinked pea (r).

If a cross between a smooth pea plant and a wrinkled pea plant gave rise to 50% phenotypical wrinkled pea plants (rr genotype, because the wrinkled shape can only express itself if it is in a homozygous state), it means that the smooth pea parent plant is heterozygous for pea shape (Rr) i.e. the allele for smooth shape was masking that of wrinkled shape in the smooth pea parent plant.

Answer:

Terms associated with gastrulation includes blastula, gestation, germ layers, endoderm, mesoderm, ectoderm e.t.c

Explanation:

Gastrulation is a process involving a complex series of cell shape changes and cell movement that occurs in the blastula. It occurs during the development inside the womb over a period of time before birth.

The period of development is known as Gestation. These cells move and rearrange dramatically in the blastula creating the embryonic tissue layers which in turn produces the tissue and organs of the adult animal.

Blastula is an animal embryo or egg at the early stage an early stage of development when the cells are still in the shape of balls.  

Germ layers: the formation of the embryonic tissue

During the gastrulation process, three germ layers are formed

1) Endoderm: the inner most layer  

2) Mesoderm: Middle layer

3) Ectoderm: outermost layer

Cells that are tightly attached to each other via junctions will move as cell sheets

Invagination – Cell sheet dents inward  

Involution – Cell sheet rolls inward

Delamination – Cell sheet splits in two  

Ingression – Cells break away from cell  sheet and migrate as individual cells

Archenteron- or embryonic gut/digestive cavity of the embrayo which eventually becomes the digestive tract

Blastoderm: is a single layer of embryonic tissue that later develops to the blastula and divides into the three germ layers from which the embrayo develops

Answer: Both cell types will undergo apoptosis

Explanation:

cytochrome C functions in the mitochondria and plays an important role in the synthesis of Adenosine Triphosphate (ATP). When a cell receives an apoptosis stimulus Cytochrome C is released from the mitochondria into the cystol to activate caspase cascade thereby committing the cell to the death process. Cytochrome C triggers programmed cell death through apoptosis. Cytochrome C release is caused by swelling of the mitochondrial matrix.

Answer:

True

Explanation:

Three layers are found in a given mammalian eye and since cow is also a mammal the same applies to it.

The three layers are as follows :

1. Fibrous layers - it is the outermost layer that consists of the sclera and the cornea.

2. The vascular layer - it is the middle layer and is vascularized. it consists of the iris, the ciliary body, and the choroid.

3. The neural layer- it is the innermost layer that consists of the retina.

In a cow's eyes, these three layers are present however only the uppermost fibrous layer is visible from the superficial surface because the vascular and the neural layers lie deep to the fibrous layer.

Answer:

True

Explanation:

The fibrous layer is the external layer of eyeball wall. The fibrous layer is a connective tissue that is not connected with blood supply thus it is avascular tissue. This tissue contains eyeball contents. The opaque sclera consist of around 90% of posterior side of fibrous layer. The cornea consist of around 10% of fibrous anterior portion of eye. The layers like neural and fibrous are deep. Thus, it is not possible to observe these layers. So, only the fibrous layer can be observed in its entirety from the superficial surface of the cow eye.

Answer:

A trait that is altered easily by small changes in diet.

Explanation:

The phylogenetic tree explains the evolutionary relationship between the organisms. The phylogeny of the organisms will depend on the difference and similarities in their genetic or physical characters.

The traits that are used in phylogeny must be constant and present in the ancestors or in atleast a group. The trait that can be easily modified or changed cannot be used for the study of the evolutionary relationship. Hence, trait which is altered by diet cannot be used in phylogenetic analysis.

Thus, the correct answer is option (C).

Answer:

The sequence does not mutate.

Explanation:

The conserved sequences may be defined as the identical or the similar DNA sequences that shows similarity in different group of organism. TATA box sequences is the example of conserved sequences.

These conserved sequences has been maintained by the phenomena of the natural selection. These sequences remain conserved throughout the evolution process. The conserved sequences cannot be mutated easily and present from the different geologic time.

Thus, the correct answer is answer is option (B).

Answer:

DNA damage signaling processes are essential foe regulating the G0 transition within the cell cycle.

Explanation:

Cell cycle is a process which prepares a cell for division.Cell cycle has various phases G0 phase,G1 phase,S phase,G2 phase and M phase.Each phase is specialized for its particular function.

      Every phases of a cell cycle is under tight regulation of various proteins and this regulation is very much important to maintain the normal level of principle constituents of a cell.

   DNA damage is detected by G1 cyclin CDK protein which transit the cell containing the damaged DNA into the G0 phase or quiescent phase for repair and if the damage cannot be repaired then the cell containing damaged DNA is targeted for destruction by ubiquitin pathway.

This is an example of an Epigenetic effect.

Explanation:

It is the study of heritable changes in the expression of genes, that are not involved in the changes present in DNA sequence. It is regular and naturally occurred, sometimes factors are responsible like age, lifestyle and disease state.

At times it leads to more damaging effect that can cause cancer. So this is also related to various fatal disease. During adulthood epigenetic effect remains stable. It does not occur in mother womb, but during the lifespan. This epigenetic effect can be reversed.  

Answer:

Explanation: red squirrels, who actively defend territories

Ant nests in an abandoned field

Buffalo grazing on a prairie

Bluegills swimming in a northern lake

Answer: Escherichia coli bacteria cause urinary tract infection in older men

Explanation:

A urinary tracts infection is an infection around the urinary systems like bladder, kidneys and urethra. It is majorly caused by Escherichia coli bacteria in older men. It can be treated by medical professional when diagonised. This infection is common in men of 50 years upward.

Prostrate hypertrophy is an infection of the prostrate gland that cause enlargement of prostrate gland making urine difficult. The disease is age associated, it is found in older men of 50years upward. It is caused by bacteria.

Answer:D

Gametic isolation is a type of prezygotic barrier where the gametes (egg and sperm) come into contact, but no fertilization takes place. Gametes may be unable to recognize one another in different species.

Answer:

A) Any butterfly allele that allowed milkweed toxin storage would be likely to persist because butterflies that had it were more likely to survive.

Explanation:

Butterflies are natural preys to birds. Over time, some butterflies evolved adaptive strategy such as developing an allele which enables storage of toxin from milkweed as a form of defense mechanism. This stored toxins repel birds from eating the butterflies having this allele giving rise to the survival of these butterflies overtime. Butterflies that had it are likely to be highly favored for survival against predatory birds, while those butterflies without this allele are likely to be heavily preyed upon by birds.

Answer: pumps, passive and active transport.

Explanation:

The plasma membrane separate the cell from external environmental, it is selectively permeable.

The plasma membrane is made of lipid bilayer. Only lipid soluble molecules can diffuse through the lipid layer. Water and ions are impermeable and require carrier mediated transport.The plasma membrane also contain integral protein that control the entry and exit of polar molecules and ions through transport mechanism.

Transport mechanism are

1. Passive transport

2. Active transport

3. Pumps

The plasma membrane regulates the movement of substances in and out of the cell through selective permeability and processes like passive and active transport. Additionally, it contains protein channels and carrier proteins that assist in the transfer of specific molecules.

The plasma membrane, also known as the cell membrane, controls what enters and leaves the cell through its selective permeability. This means it only allows certain substances to cross it. This is achieved through various processes including passive transport (like diffusion and osmosis), where substances move from an area of high concentration to low concentration; and active transport, where the cell uses energy to move substances against their concentration gradient. Moreover, the plasma membrane also has protein channels and carrier proteins that assist in the tranportation of specific molecules.

https://brainly.com/question/33587586

#SPJ6

Answer:

D) Neither of the parental genes is dominate over the other.

Explanation:

Since the trait on the offspring is a mixture from both parent, it means that neither of the alleles from both parents is completely dominant over the other. Instead, each of the alleles contributes equally to the trait of the offspring.

This effectively explains the fact that each trait exhibited by offspring is a blend of the traits from the two parents.

The correct option is D.

Answer:

The women has a genotype of hhff and the man has a genotype of HhFf

Explanation:

From the results of the children we can see that widows peak and long fingers are dominant because it has the majority in the family. The question is are the parents homozygous dominant. The are not. They are heterozygous because if they were homozygous they wouldn’t be able to have any recessive genes transfer to the children