Answer:
The Rb will always stay active
Explanation:
The Rb, undergoing a mutation that promotes cell proliferation, the cells will proliferate excessively, either benignly or malignant, forming a tumor structure.
The Rb mutation is considered an irreversible process, which will generate an unlimited and excessive growth that is abnormal when compared to the other non-mutated cells.
How did the death of chestnut tree result in the growth of the ecosystem
Answer:
add nutrients to the soil.
Explanation:
The death of chestnut tree result in the growth of the ecosystem because when the chestnut tree dies, the decomposers such as fungi and bacteria start feeding on the dead tree and as a result nitrogenous waste is produced mixed with soil which is the essential nutrient for the plants. These nitrogenous waste is used by the plants to make amino acids and as a result the growth of an ecosystem occurs.
Question 22 (5 points)
The major difference between B cells and T cells is that
T cells do not produce antibodies.
B cells do not produce antibodies.
B cells always circulate in the blood stream.
T cells always circulate in the blood stream.
Answer:
B cells always circulate in the blood stream
Explanation:
just took test pf.
Caffeine prolongs and intensifies the effects of epinephrine. Which of the following potential mechanisms of action of caffeine is consistent with this effect?
a. inhibits cAMP phosphodiesterase, the enzyme that converts cAMP to AMP.
b. a competitive antagonist of cAMP binding to PKA.
c. stimulates phospholipase Cb.
d. inhibits sarcoplasmic/endoplasmic reticulum Ca 2 + - ATPase.
e. activates PKC.
Answer:
a. inhibits cAMP phosphodiesterase, the enzyme that converts cAMP to AMP.
Explanation:
The phosphodiesterases are a group of enzymes that are capable of breaking phosphodiester bonds such as those between nucleotides in nucleic acids. The Cyclic adenosine monophosphate (cAMP) is a second messenger involved in intracellular signaling pathways. This molecule (cAMP) is hydrolyzed by the cAMP-dependent phosphodiesterase, which catalyzes the enzymatic breakdown of phosphodiester bonds (i.e., hydrolyzing cAMP to 5-AMP). The cAMP levels are modulated by the balance between its generation and the degradation via cyclic nucleotide phosphodiesterase.
1. You are given a 1 gram soil sample of unknown bacterial load. After doing 10-fold serial dilutions of the soil in sterile water, 100 uL volumes are taken from each dilution for preparation of pour plates. Following incubation, each half of the 10-8 plate has 46 colonies.
a) What was the dilution factor?
b) How many bacteria were present in the soil?
2. Staphylococcus aureus divides every 20 minutes. A culture begins with 10 bacterial cells.
a) After 5 hours, how many generations have occurred
b) After 5 hours, how many bacteria are present?
3. How many milliliters would you need to prepare a 10-2 dilution from a 10ml starting culture?
Answer:
1a. 1:10
1b. 4.6×10¹³
2a. 15generations
2b. 327,680
Explanation:
10 fold serial dilution means 1ml of stock is mixed in 9ml distilled water. This is called as 10⁻¹ solution.
In this way, take 1ml each of every dilution and mix in 9ml distilled water to make 10⁻², 10⁻²-------10⁻⁸ dilutions.
Now, CFU/ml = no. of colonies × dilution factor/ volume of sample plated.
In the intrinsic pathway, the reaction begins with clotting factors from the _.
Answer:
Clotting factors are circulating in the blood.
Explanation:
In the intrinsic pathway, the body is responding intravascular damage through binding of platelets, exposure of chemicals or even collagen from endothelial membranes. The most of the clotting factors are synthesized by the liver and circulate around the blood stream until they are needed or until they are degraded based off their half lives.
When the platelets start to aggregate they release chemicals and have proteins that can attract the clotting factors. In the intrinsic pathway, clotting Factor XII starts off the cascade. Hope that helped :)
avier stepped on a splinter while walking barefoot. The splinter pierced deep into his foot and caused a great amount of pain. What is the appropriate pathway of pain sensation from the spinal cord into the brain
Answer:
Answered below
Explanation:
On piercing his foot, the pain receptors called nociceptors, found in the skin, are activated. Nociceptors exist at the nerve endings of the primary afferent neurons. Signals travel along the first order neurons which have cell bodies within the dorsal root ganglia of the spinal cord. In the dorsal root ganglia, the signals are taken up at the synapse with the second order neurons which have cell bodies in the nuclei of the cranial nerves within the brainstem. These neurons ascend cranially in the spinothalamic tract to the thalamus. The third order neurons lie within the ventral posterolateral nucleus of the thalamus. They terminate at the somatosensory cortex where the signals are being processed and returned as a sensation of pain.
The central (Haversian) canal that runs through the core of each osteon is the site of ________. adipose tissue and nerve fibers cartilage and interstitial lamellae blood vessels yellow marrow and spicules
Answer:
Blood vessels and nerve fibers
Explanation:
The Haversian canal serves as the bone tissues and it runs through the core of each osteon. The osteon surrounds the Haversian canal and contain structures called lamellae.
These lamella are made largely of collagen fibers and also various network of rich blood vessels and cells which produces blood cells in the body. Nerve cells which helps in the relay of impulses are also present. The rich contents of the bone gives it its strength and durability.
Answer:
The correct answer is: blood vessels and nerve fibers.
Explanation:
Haversian Canals are a group of tubes that are located in the more peripheral region of the bone, known as the cortical bone. The cortical bone is hard and compact and is composed of several concentric layers of bone cells (osteocytes and osteoblasts) that circle around a haversian canal, which contains capillaries and nerve fibers. This structure is called an osteon.
Haversian Canals are very important for the correct functioning of the bone, as they give the cells their needed blood supply and innervation.
4. In the background, the presence of naturally occurring enzymes in fruits and vegetables was discussed. Using your results from this exercise as a basis to guide your thoughts, do you think that cooked, frozen, or raw fruits and vegetables would contain the most active enzymes?
Answer:
The fruits inside do not have enzymes, but if our body when digesting them, if these fruits are cooked they are much easier to digest by our digestive enzymes and if they are raw, digestion will be more laborious since it will have to break more masses chemicals that were not destroyed by cooking.
Regarding freezing, it does not intervene in digestion.
Explanation:
The cooking of vegetables or fruits like meats generates that some chemical unions are destroyed, thus exposing the most internal structures in enzyme activity.
A farmer plants Bt cotton that is genetically modified to produce its own insecticide. Of the cotton bollworms feeding on these Bt plants, only 5% survive unless they have at least one copy of the dominant resistance allele R that confers resistance to the Bt insecticide. When the farmer first plants Bt cotton, the frequency of the R allele in the cotton bollworm population is 0.01. What will the frequency of the resistance allele be after one generation of cotton bollworms fed on Bt cotton [answer]
Answer:
the frequency of the resistant allele after one generation is 0.989
Explanation:
Given that :
A farmer plants Bt cotton that is genetically modified to produce its own insecticide.
Of the cotton bollworms feeding on these Bt plants, only 5% survive
i.e the survival rate s = 5% =0.05
unless they have at least one copy of the dominant resistance allele R that confers resistance to the Bt insecticide
Frequency of R allele = 0.01
In order to determine what will the frequency of the resistance allele be after one generation of cotton bollworms fed on Bt cotton; we need to first determine the frequency of the recessive allele r.
According to Hardy-Weinberg Equilibrium ;
p+q = 1
Let p = R and q = r
R + r = 1
0.01 + r = 1
r = 1 - 0.01
r = 0.99
Now; the frequency of the resistance allele after one generation can be calculated as :
[tex]q' = \dfrac{q(1-sq)}{1-(sq^2)}[/tex]
where ;
q' = R
q = r
[tex]q' = \dfrac{0.99(1-(0.05 \times 0.99))}{1-(0.05 \times 0.99^2)}[/tex]
[tex]q' = \dfrac{0.99(0.9505)}{1-(0.049005)}[/tex]
[tex]q' = \dfrac{0.940995}{0.950995}[/tex]
q' = 0.989
Thus; the frequency of the resistant allele after one generation is 0.989
How can we determine the population of soil?
Answer:
by the depth of the soil
Question 21 (5 points)
Which of the following terms describes a collection of hollow cells that implants on
the uterus wall after fertilization, but is not yet differentiated (in other words, all cells
are the same type of cell still)?
Fetus
Haploid
Mitosis
Blastocyst
Answer:
The answer is option D.
Blastocyst
Hope this helps
Answer:
Blastocyst
Explanation:
Once an egg is fertilized by a sperm, it begins to divide by mitosis into a 2, 4, and then 8 celled structure. Eventually, this large collection of cells keeps dividing and becomes a hallow collection of undifferentiated cells called a blastocyst. The blastocyst will implant on the wall of the uterus where it will begin to grow and develop during pregnancy into a fetus.
HELP!!!!!!!!!!!
Which are considered two of the special properties that are used to identify certain minerals?
O hardness and luster
O magnetism and fluorescence
O streak and color
O cleavage and fracture
Answer:
The answer is
2. magnetism and fluorescence
Explanation:
The other properties mentioned are common properties that are used to identify all minerals. As you can see, hardness, color and fracture are common properties that cut across all minerals. Magnetism and fluorescence however, are not very common and are found in only a few special minerals. That is why they are considered special properties.
Hope this helps!
magnetism and fluorescence are considered two of the special properties that are used to identify certain minerals. Thus option B is correct.
what are the properties to identify an object ?
Minerals are the chemical compound which has a well -defined composition and a specific crystal structure and occurs naturally in the pure form.
If a compound occurs naturally in different crystal form then it is referred as a different mineral. The chemical composition of a mineral varies depending on the presence of small impurities which are present in small quantities.
Some minerals can have variable proportions of two or more chemical elements which occupy equivalent position in the crystal structure; it has variable composition which is split into separate species.
minerals include color, streak, luster, specific gravity and cleavage as their physical properties, shows no magnetism. Basically magnetism is the physical property of the minerals, magnetism does not have these elements. thus, have no magnetism called diamagnetic. Examples of diamagnetic are quartz, apatite and calcite.
For more details mineral, visit
https://brainly.com/question/1890462
#SPJ6
Exchange of respiratory gases takes place in an earthworm through (A) moist skin (B) gills (C) trachea (D) lungs
The lungs is the answer
Explanation
Earthworms do not have specialized respiratory organs like we do; instead, they take in oxygen and expel carbon dioxide directly through their skin. Oxygen diffuses through the earthworm's body surface and diffuses inward to the network of capillaries lying just under the body surface.
Answer:
I believe skin is the answer on edg.
Explanation:
Which statement summarizes a change that occurs during photosynthesis?
Answer:
It converts light energy to chemical energy.
Explanation:
Its absorbing sunlight and changing in to chemical energy for the plants nutrients.
During photosynthesis, light energy will be changed into chemical energy.
What is photosynthesis?Photosynthesis was a process used mostly by plants as well as other creatures to transform sunlight into chemical energy which, via cellular respiration, might subsequently be produced to fuel the organism's functions.
What is chemical energy?Chemical energy was the energy that would be generated while chemical substances engage in a chemical reaction but also change into some other substances.
Therefore, during photosynthesis, light energy will be changed into chemical energy.
To know more about photosynthesis and chemical energy.
https://brainly.com/question/1388366
#SPJ3
Protein is needed for growth and repair.
The digestion of protein begins in the stomach and is completed in the small intestine,
What are the products of the digestion of protein.
Tick the correct box
amino acids
energy
sugars
vitamins
1 mark
Amino acids
O Energy
O Sugars
Vitamins
Answer:
Amino acids
Explanation:
Hope it helps.
The Punnett square shows the results when two parent cows are crossed.
R represents the allele for red hair, and r represents the allele for white hair.
Which best describes this inheritance pattern?
A) Incomplete dominance because the intermediate form of the trait is chosen
B) Co-dominance because the intermediate form of the trait is chosen C) Incomplete dominance because the offspring display alleles for both hair colors
D) Co-dominance because the offspring display alleles for both hair colors
Answer:
A
Explanation
the red haired trait is dominant over the white haired trait. and the results are all red haired offspring. therefore its incomplete dominance
The correct option is D) Co-dominance because the offspring display alleles for both hair colors.
What is Co-dominance?Co-dominance refers to a phenomena, in which both alleles are simultaneously expressed in the heterozygote.
Incomplete dominance is closely related to Co-dominance in which phenotype of the progeny is intermediate of the parent phenotype.
Here, the red haired trait is dominant over the white haired trait and still both alleles are simultaneously expressed in the heterozygote of the offspring with red and white hair traits, thus, the Co-dominance best describes this inheritance pattern.
Learn more about, Co-dominance, here;
https://brainly.com/question/7148836
#SPJ6
Which combination forms a covalent bond?
A. Two carbon atoms
B. Two oxygen molecules
C. Two water molecules
D. Two sodium atoms
SUSMIT
!!!
Answer:
A. Two carbon atoms
Explanation:
We know that covalent bond occurs when there are two non - metallic atoms and carbon atoms are non-metallic so it is the answer.
Hope it helps and pls mark as brainliest :)
At your laboratory you are observing skin cells labeled 'defective' to determine what is wrong with them. After careful observation you notice that the cytoskeleton is there, but the cell is still having trouble maintaining its shape. Infer what could be damaged.
A. Cell wall
B. Capsule
C. Cilia
D. Actin filaments
Answer:
D. Actin Filaments
Explanation:
Actin filaments are part of cytoskeleton and they are the central key player in maintaining cell shape and movement. So my guess is that since cytoskeleton is present, there is something likely wrong with the actin filament.
Even in the presence of the cytoskeleton, the shape is not maintained in the cell due to the damaged actin filaments. Thus, option D is correct.
What are actin filaments?Actin filaments are the part of the cytoskeleton that forms bundles and meshworks to provide the cell shape and structure. They are the central part of the cell shape and motion.
As the cytoskeleton is present then, there is the possibility that the actin filaments of the cells are damaged so that the cell is not able to maintain the cell shape.
Cell wall, capsules, and cilia have no role in the animal cell like the skin cells to maintain the cell shape as animal lacks cell wall in the structure and are not involved in providing cell shape.
Therefore, the actin filament is damaged.
Learn more about actin filaments here:
https://brainly.com/question/13916606
#SPJ2
Which word identifies the hanging icicle-shaped formations in caves that are created by deposition?
Answer:
Stalactites
Explanation:
A stalactite is a type of formation that hangs from the ceiling of caves, hot springs, or manmade structures such as bridges and mines. Any material that is soluble, can be deposited as a colloid, or is in suspension, or is capable of being melted, may form a stalactite.
Answer:the answer is,
Stalactites
Explanation:
I just took the test
what is cellular affinity in biology?
Answer:
affinity. Attraction between particles. Biology: A measure of the attraction of one biological molecule toward another molecule, either to modify it, destroy it, or form a compound with it. Examples are enzymes and their substrates, or antibodies and their antigens.
Which structure is represented by the X?
Answer:
May be trachea
Explanation:
Antimicrobial peptides can do all of the following except:_________A) regulate body temperature.B) target intracellular components.C) insert themselves into target cell membranes.D) disrupt plasma membrane and/or cell wall.E) stimulate leukocytes.
Answer:
Option A
Explanation:
Antimicrobial peptides cannot regulate body temperature. They can do all of the rest.
=> target intra cellular components.
=> insert themselves into target cell membranes.
=> disrupt plasma membrane and/or cell wall.
=> stimulate leukocytes.
Question 11 (5 points)
Which of the follow best decribes the function of a ligament?
Connect muscles to other muscles
Connect muscles to the nervous system
Connect bones to other bones
Connect muscles to bones
Answer:
Connects Bones to other Bones.
Explanation:
A ligament is a tissue that connects two bones together to form a joint.
Answer:
connect bones to other bones
Explanation:
Ligaments connect bones to other bones. Tendons connect bones to muscles.
What are gyres?
1.Large plants that move in circles in the ocean.
2.Large circulating parts of the ocean
3.Large animals in the ocean that move in circles in the ocean.
Answer:
A gyre is a circular ocean current formed by the Earth's wind patterns and the forces created by the rotation of the planet..
Explanation:
follow me plzzz
DNA damage checkpoints are crucial for preventing cell proliferation when DNA damage has occurred. The role of DNA checkpoint proteins in the cell cycle is closely tied to the roles of DNA repair enzymes, although these proteins perform different functions.1. Which of the following statements is true for DNA checkpoint proteins and not for DNA repair enzymes? a. These proteins remove a single nucleotide of damaged DNA. b. These proteins nick the phosphodiester backbone of the damaged DNA. c. These proteins prevent the cell cycle from progressing if damaged DNA is detected. d. These proteins remove the region of damaged DNA. 2. Which cell cycle phases contain critical DNA damage checkpoints?a. Gob. G1c. G2d. M
Answer:
1. C. These proteins prevent the cell cycle from progressing if damaged DNA is detected.
2. C. G2
Explanation:
1. All other choices apply uniquely to DNA repair enzymes (i.e. not to DNA checkpoint proteins).
2. Go doesn't contain any critical DNA damage checkpts. because it's not even an official part of the cell cycle; it's simply a phase in which cells are arrested. G1 doesn't contain any critical DNA damage checkpts. because it's before DNA is replicated. G2 is right after S phase when the DNA is replicated; thus, it contains critical DNA damage checkpts.
About Galileo Galilei : Why was he allowed to serve his sentence from home?
Early in 1616, Galileo was accused of being a heretic, a person who opposed Church teachings. ... Galileo was sentenced to life imprisonment in 1633. Because of his age and poor health, he was allowed to serve his imprisonment under house arrest.
Explanation:
Fill in the blanks with appropriate wods.
1. A process called__________ helps to propel first the bolus and then chyme forward through the esophagus, stomach, and small intestine.
2. Nutrients are absorbed through the lining of the small intestine via a variety of mechanisms. Most nutrients require______________ , where a specific carrier protein is utilized, but no energy is required.
3. Some smaller molecules can cross via_____________ , Like with facilitated diffusion, no energy is required because the concentration of a nutrient is higher inside the GI tract than in the enterocyte. Unlike with facilitated diffusion, however, no ____________ is needed.
4. Nutrients like glucose and amino acids are absorbed through ______________ , which requires both a carrier protein and energy in the form of ATP.
5. A fourth method is called _____________ , which involves a vesicle that forms from the enterocyte's cell membrane, engulfing the nutrient and then drawing the nutrient into the cell.
6. Once absorbed, water-soluble nutrients like carbohydrates and amino acids enter capillaries and travel to the liver via the ___________ .
7. Fat-soluble nutrients initially travel via the _____________ before entering the bloodstream.
8. Most water is absorbed in the _____________ , and solid waste is then eliminated.
a. Large intestine
b. Peristalsis
c. Passive diffusion
d. Carrier protein
e. Active transport
f. Facilitated diffusion
g. Endocytosis
h. Lymphatic system
i. Hepatic portal vein
Answer:
1. b. Peristalsis
2. c. Passive diffusion
3. Facilitated diffusion, d. Carrier protein
4. e. Active transport
5. g. Endocytosis
6. i. Hepatic portal vein
7. h. Lymphatic system
8. a. Large intestine
Explanation:
1. peristalsis helps to propel first the bolus and then chyme forward through the esophagus, stomach, and small intestine.
2. Nutrients are absorbed through the lining of the small intestine via a variety of mechanisms. Most nutrients require passive diffusion, where a specific carrier protein is utilized, but no energy is required.
3. Some smaller molecules can cross via facilitated diffusion Like with facilitated diffusion, no energy is required because the concentration of a nutrient is higher inside the GI tract than in the enterocyte. Unlike with facilitated diffusion, however, no carrier protein is needed.
4. Nutrients like glucose and amino acids are absorbed through active transport which requires both a carrier protein and energy in the form of ATP.
5. A fourth method is called endocytosis which involves a vesicle that forms from the enterocyte's cell membrane, engulfing the nutrient and then drawing the nutrient into the cell.
6. Once absorbed, water-soluble nutrients like carbohydrates and amino acids enter capillaries and travel to the liver via the hepatic system
7. The lymphatic system helps in traveling of the Fat-soluble nutrients initially, before entering the bloodstream.
8. Most water is absorbed and solid waste is then eliminated. in the large intestine
Jose Salazar has been hospitalized following a motor vehicle accident. He has several broken bones, including his left jaw, two ribs on the left side, and a compound fracture of his left leg. According to his medical record, he is 47 years old, his height is 5'9", and his weight is 171 pounds. During the course of his hospital stay, he was diagnosed with a heart arrhythmia. His current medications include lovastatin to lower his cholesterol, an MAO inhibitor to treat depression, and an analgesic to treat his pain. Mr. Salazar's wife also reports that he takes several herbal products including yohimbe, kava, valerian, and St. John's wort. Which herbal product taken by Mr. Salazar may be causing his heart arrhythmia?a. yohimbeb. kava kava onlyc. St. John's wortd. valerian onlye. both valerian and kava kava
Answer:
a. yohimbeb
Explanation:
Heart arrhythmia is a heart disease in which the heart does not work properly. The main cause of heart arrhythmia is yohimbeb which is used as a medicine for increasing sexual desires but this herbal product also has side effects such as causing heart problems such as heart arrhythmia and kidney diseases. So the Jose Salazar should avoid the consumption of yohimbeb in order to control the heart disease.
About 16% of the world's total oil output:
A) comes from offshore drilling
B) is made by the United States
C) is mined deep beyond the continental shelf
D) comes from oil rigs in the Atlantic Ocean
Answer:
The answer is A, It comes from offshore drilling.
Explanation:
Cause i got it right.
"During the process of nerve impulse transmission, when sodium flows into the neuron, its cell membrane is"
Answer:
The neuron cell membrane is partially permeable to sodium ions, so sodium atoms slowly leak into the neuron through sodium leakage channels. The cell wants to maintain a negative resting membrane potential, so it has a pump that pumps potassium back into the cell and pumps sodium out of the cell at the same time.
During the process of nerve impulse transmission, when sodium flows into the neuron, its cell membrane is depolarized.
The nerve impulse is an electrical impulse, so that the electrical impulse is transmitted, the positive sodium ions that are present outside the neuron in a state of rest must pass through the cell membrane.
In a state of rest, the interior of the neuron has a negative electrical charge (repolarized membrane).
When positive sodium ions enter the neuron, they change the internal charge from negative to positive (depolarized membrane).
This increase is due to the constant number of sodium ions, positively charged, inside the membrane of the neuron.
This depolarization is the first step in the generation of an action potential, that is, the emission of a message.
In other words, it is the part of the process that causes an electrical signal to be released, which will end up traveling through the neuron to cause the transmission of information through the nervous system.
Therefore, we can conclude that during the process of nerve impulse transmission, when sodium flows into the neuron, its cell membrane is depolarized.
Learn more here: https://brainly.com/question/6174965