Answer:
The question is incomplete, below is the completed question:
The main function of a cell membrane is to allow substances to enter and leave the cell. Which is a correct description of transport through a cell membrane ?
a. Diffusion, or passive transport, occurs when molecules diffuse from a lower concentration to a higher concentration.
b. Facilitated transport occurs when proteins that extend through the cell membrane provide a channel through which certain substances can diffuse more rapidly than by passive diffusion.
c. The lipid bilayer opens up and allows the ions or molecules to enter the cell, then closes.
d. Active transport occurs when molecules diffuse from a higher concentration to a lower concentration.
Answer:
b. Facilitated transport occurs when proteins that extend through the cell membrane provide a channel through which certain substances can diffuse more rapidly than by passive diffusion.
Explanation:
Transport through cell membranes can be broadly classified as active transport or passive transport.
Active transport requires energy in the form of ATP for the transportation of substances across the cell membrane.
Option b correctly describes facilitated diffusion, which is a passive-mediated diffusion process, where channels in the cell membrane mainly composed of proteins called transmembrane integral proteins, allow for the movement of certain molecules (mostly polar/hydrophilic) molecules that will not otherwise be transported through simple diffusion because of the hydrophobic nature of the cell membrane.
The other options are wrong because:
a. diffusion or simple transport involves the movement of substances from regions of higher to a lower concentration not lower to higher as suggested here.
c. The lipid bi-layer does not allow ions or hydrophilic molecules because it is hydrophobic in nature, and it is not a channel, so it does not open and closes
d. In active transport, transfer of molecules is from regions of lower to higher concentration and not higher to lower concentration as suggested here.
(06.03 LC) Which of the following is an example of how HIV can be transmitted from one person to another? Contact between infected blood and a mucus membrane Contact between infected saliva and an open wound Contact between infected blood and skin Contact between infected saliva and lining of mouth
Answer:
i believe the answer is contact between a infected blood and a mucus membrane
Explanation:
____________ a regulatory protein that may bind DNA to inhibit transcription. ____________ a DNA sequence that binds a regulatory protein. ____________a DNA sequence that binds RNA polymerase and regulates transcription. ____________a compound that interacts with another protein or compound to form an active repressor ____________a compound that induces or activates transcription, such as lactose.a. Repressorb. Operator c. Promoterd. Corepressore. Inducer
Answer:
A repressor is a regulatory protein that may bind DNA to inhibit transcription. An operator is a DNA sequence that binds a regulatory protein. A promoter is a DNA sequence that binds RNA polymerase and regulates transcription. A corepressor is a compound that interacts with another protein or compound to form an active repressor. An inducer is a compound that induces or activates transcription, such as lactose.
Explanation:
Repressor proteins bind to DNA and RNA to suppress target gene expression. A DNA repressor blocks transcription by inhibiting the attachment of RNA polymerase to the promoter sequence, while an RNA repressor bind to the mRNA to block translation of the protein. An operator is a DNA sequence required for the attachment of transcription factors. The genes that are transcribed by the binding of a transcription factor to an operator sequence are collectively referred to as an operon. Operons are generally found in prokaryotes but they also can be found in some eukaryotes including Caenorhabditis elegans and Drosophila melanogaster. An inducer is a molecule that activates gene transcription either by binding to repressors/corepressors (thereby inactivating their functions) or by binding activators. For example, the allolactose act as an inducer of the lac operon.
Which sentence about protist is accurate
Answer:
there are no sentences
Explanation:
Why are G proteins known as guanine nucleotide-binding protein?
Answer:
G proteins, also known as guanine nucleotide-binding proteins, are a family of proteins that act as molecular switches inside cells, and are involved in transmitting signals from a variety of stimuli outside a cell to its interior. ... G proteins belong to the larger group of enzymes called GTPases.
In the image, the arrow Is pointing to a celestial object. Which attribute disqualifies the object from being a planet?
A. It appears to have no moons.
B. It is spherical in shape.
C. Its neighborhood is not clear.
D. It has horizontal bands on its surface.
The correct answer is C. Its neighborhood is not clear.
Explanation:
One of the key features of a planet is that it clears its neighborhood; this means the planet gravitational force is strong enough that there are no other celestial bodies on its orbit or next to it except by its moons or satellites. This does not occur in the image presented because there are smaller celestial bodies near to the main or bigger celestial body. This likely occurs if the celestial body is not big enough to clear its neighborhood, and therefore it is not a planet.
A.While the traits studied in Exercise 1 were hypothetical genetic traits, what type of genetic traits do you think are important to study and predict
Answer:
Genetic disturbances harmful to the organism are genetic characteristics that must be studied and predicted.
Explanation:
Genetic disorders that harm an organism such as sickle cell anemia, hemophilia, Turner syndrome, among others, are important to be studied and predicted, because it will provide better maintenance of that organism. Allowing people who inherit these characteristics to have more efficient treatments and a better life, since the prediction of these characteristics allows the family to establish better adapapitativo methods, that will make the life of this individual easier and with more quality.
QUICKLY! The chemical reaction equation of photosyntesis is shown here: What information is not given in this equation. It does not show if the reaction is reversible. It does not show the reactants needed for the reaction. It does not show that photosynthesis consists of many separate steps. It does not show the number of molecules required to produce glucose.
Answer:
C: It does not show that photosynthesis consists of many separate steps.
Explanation:
Photosynthesis is a unique process carried out by the cells of autotrophic organisms. It is the process whereby they synthesize their own food in form of sugars (glucose) in the presence of sunlight. Ideally, the photosynthetic process makes use of carbon dioxide (C02) and water (H20) in the presence of light energy (from sun) to produce glucose sugar (C6H12O6) and oxygen (02). The general photosynthetic equation is as follows:
6CO2 + 6H20 + light → C6H12O6 + 6O2
However, the process is not as simple as portrayed as it involves many separate steps that collectively forms the photosynthetic product (glucose). Photosynthesis occurs in two major stages namely: light stage and light independent stage, which in turn consists of series of reactions that forms the products.
Therefore, the equation attached to this question describes photosynthesis but It does not show that photosynthesis consists of many separate steps.
Answer:
C: It does not show that photosynthesis consists of many separate steps.
Explanation:
What makes up the backbone of a DNA molecule? nucleic acids RNA molecules sugars and phosphates ribose and deoxyribose
Answer:
sugars and phosphates
Explanation:
gradpoint
A mutation that hides the effect of another mutation at a site that is distinct from the site of the original mutation, but with in the same gene. This mutation is best described as a
Answer:
The correct answer is intragenic suppressor mutation.
Explanation:
A suppressor mutation partially or completely converses the effects of a different mutation. A suppressor mutation is of two kinds, that is, an intragenic suppressor and an intergenic suppressor. An intragenic suppressor converses the influence of a mutation at a distinct site in a similar gene.
On the other hand, an intergenic suppressor converses the influence of a mutation at a distinct locus of the gene. It is the intragenic suppressor mutation, which takes place in a similar gene where the occurrence of the first mutation had taken place. Therefore, the mutation, which hides the influence of another mutation at a location, which is different from the location of the original mutation, but taking place in a similar gene can be illustrated as the intragenic suppressor mutation.
What complications might arise from genetic screens targeting an organ that differentiates late in development?
Answer:
No sign of testicular development in boys and breast development in girls.
Explanation:
Complications like no sign of testicular development in boys and breast development in girls occurs if an organ develop very late. There are many causes of this type of complications such as long term illness, eating improper food and disorder of sexual development. Sometime these complications also occurs due to genetically. These complications should be treated well with medication and use of nutritious food. These medicines increases the performance of sex hormones in order to initiate puberty.
When the body cells are hypotonic to the blood plasma, water will move from intracellular fluid to extracellular fluid.
A. True
B. False
Answer:
True
Explanation:
