Answer:
Introduction
Does cell cycle control matter? If you ask an oncologist – a doctor who treats cancer patients – she or he will likely answer with a resounding yes.
Cancer is basically a disease of uncontrolled cell division. Its development and progression are usually linked to a series of changes in the activity of cell cycle regulators. For example, inhibitors of the cell cycle keep cells from dividing when conditions aren’t right, so too little activity of these inhibitors can promote cancer. Similarly, positive regulators of cell division can lead to cancer if they are too active. In most cases, these changes in activity are due to mutations in the genes that encode cell cycle regulator proteins.
Here, we’ll look in more detail at what's wrong with cancer cells. We'll also see how abnormal forms of cell cycle regulators can contribute to cancer.
What’s wrong with cancer cells?
Cancer cells behave differently than normal cells in the body. Many of these differences are related to cell division behavior.
For example, cancer cells can multiply in culture (outside of the body in a dish) without any growth factors, or growth-stimulating protein signals, being added. This is different from normal cells, which need growth factors to grow in culture.
Cancer cells may make their own growth factors, have growth factor pathways that are stuck in the "on" position, or, in the context of the body, even trick neighboring cells into producing growth factors to sustain them^1
1
start superscript, 1, end superscript.
Diagram showing different responses of normal and cancer cells to growth factor presence or absence.
- Normal cells in a culture dish will not divide without the addition of growth factors.
- Cancer cells in a culture dish will divide whether growth factors are provided or not.
Diagram showing different responses of normal and cancer cells to growth factor presence or absence.
Normal cells in a culture dish will not divide without the addition of growth factors.
Cancer cells in a culture dish will divide whether growth factors are provided or not.
Cancer cells also ignore signals that should cause them to stop dividing. For instance, when normal cells grown in a dish are crowded by neighbors on all sides, they will no longer divide. Cancer cells, in contrast, keep dividing and pile on top of each other in lumpy layers.
The environment in a dish is different from the environment in the human body, but scientists think that the loss of contact inhibition in plate-grown cancer cells reflects the loss of a mechanism that normally maintains tissue balance in the body^2
2
squared.
Another hallmark of cancer cells is their "replicative immortality," a fancy term for the fact that they can divide many more times than a normal cell of the body. In general, human cells can go through only about 40-60 rounds of division before they lose the capacity to divide, "grow old," and eventually die^3
3
cubed.
Cancer cells can divide many more times than this, largely because they express an enzyme called telomerase, which reverses the wearing down of chromosome ends that normally happens during each cell division^4
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Cancer cells are also different from normal cells in other ways that aren’t directly cell cycle-related. These differences help them grow, divide, and form tumors. For instance, cancer cells gain the ability to migrate to other parts of the body, a process called metastasis, and to promote growth of new blood vessels, a process called angiogenesis (which gives tumor cells a source of oxygen and nutrients). Cancer cells also fail to undergo programmed cell death, or apoptosis, under conditions when normal cells would (e.g., due to DNA damage). In addition, emerging research shows that cancer cells may undergo metabolic changes that support increased cell growth and division^5
5
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Diagram showing different responses of normal and cancer cells to conditions that would typically trigger apoptosis.
- A normal cell with unfixable DNA damaged will undergo apoptosis.
- A cancer cell with unfixable DNA damage will not undergo apoptosis and will instead continue dividing.
Explanation:
The fact that choanoflagellates and collar cells of sponges resemble each other supports the inference that ________. Group of answer choices choanoflagellates are animals choanoflagellates are more closely related to sponges than they are to protists choanoflagellates and sponges evolved similar cell structures through convergent evolution choanoflagellates and sponges are sister groups
Answer:
choanoflagellates and sponges are sister groups
Explanation:
The choanoflagellates are small unicellular organisms belonging to the Protista kingdom. These microorganisms are collared flagellates morphologically similar to the choanocyte cells of animal sponges, which have a central flagellum surrounded by a collar of microvilli. In consequence, it has been suggested that choanoflagellates may represent the closest living relatives of primitive metazoans (i.e., they are sister groups to sponges). This hypothesis has recently been supported by both molecular phylogenetic and comparative genomic analyses.
what is an indication that water is entering a cell?
Answer:
water decreasing from where it came from
Explanation:
that or the cell starts to swell
c) Explain why wheat is not able to grow well in
nitrate poor soil.
Answer:
When soil available nitrogen is low, yield and protein content will be low. As nitrogen is applied beyond these levels the wheat plant will no longer use it to
what would happen if you gave your dog a tiny piece of chocolate?
Explain how humans are able to produce one type of hemoglobin as they develop in utero, then produce another to use after birth
Answer:
Hemoglobin F has a different composition from the adult forms of hemoglobin, which allows it to bind (or attach to) oxygen more strongly. This way, the developing fetus is able to retrieve oxygen from the mother's bloodstream, which occurs through the placenta found in the mother's uterus.
Photosynthesis is a complex set of chemical reactions in which light energy is converted in to______________________ energy.
Answer:
chemical energy
What is Florida’s most popular gamefish
Answer:
Sailfish
Explanation:
One of Florida's most popular gamefish is the Sailfish.
Help me more point given if right
Answer:
A
Explanation:
How can a person cannot taste PTC I'd both of their parents have the ability to taste PTC?
Answer:
the parents are (Tt) and each passed down the recessive allele so the child is (tt)
Explanation:
Help me with this please
What are 5 differences between prokaryotic and eukaryotic cells?
Answer:
Go to science.org and type your question up, they have plenty of diagrams and i used it to ace all of my bio quizzes.
Explanation:
Hope this helps! Have a great day!
Please help i am giving away brainiliest
Describe the Lysogenic cycle.
No dam links
Answer:
Here ya go
Explanation:
The lysogenic cycle, is one of two cycles of viral reproduction. Lysogeny is characterized by integration of the bacteriophage nucleic acid into the host bacterium's genome or formation of a circular replicon in the bacterial cytoplasm. In some interactions between lysogenic phages and bacteria, the lysogenic conversion may occur, which can also be called phage conversion.
BRAINLES
plz help thank you
Answer:
1.70%
2.25%
3.5%
hope this helped:)))))))))))
Organisms such as yeast can reproduce through mitotic division. During this type of reproduction, nondisjunction is possible.
True
False
Please Help I will mark bRAINLIEST
Answer:
d
Explanation:
In particular, organelles called chloroplasts allow plants to capture the energy of the Sun in energy-rich molecules; cell walls allow plants to have rigid structures as varied as wood trunks and supple leaves; and vacuoles allow plant cells to change size.
In a sample of double stranded dna if 27% of the nitrogenous bases are thymine what percentage of nitrogenous bases are cytosine
Answer:
23%
Explanation:
According to Chargaff's law A = T and G = C
T = 27%
A = 27%
27 + 27 = 54
100 - 54 = 46
46/2= 23
So 23%
Flowers come in all different sizes, therefore we need different sizes of
Answer: -flower holders ?
Explanation:
A cloud of dust and gas in space were stars are formed is a _____ .
Answer:
nebula
Explanation:
Which are both forces?
A.) Work and Power
B.) Power and Gravity
C.) Gravity and Friction
D.) Friction and Work
(Need help this is due by 11:59 tonight!)
Answer:
I think that the answer might be C. Gravity and Friction
Explain how a school bus uses all of these energy types.
-Mechanical
-Chemical
-Electrical
-Thermal
Answer:
Mechanical
94 percent of all school buses in America are powered by diesel engines because of their reliability, durability and safety. Almost half of these (46 percent) rely on the cleanest, near-zero emission diesel engine technology.
Chemical
school bus uses petroleum as chemical potential energy.
Electrical
An electric bus draws electricity from the power grid and stores it in a battery that can be recharged once the electricity has been used up. This basically mirrors the way our electronics work. We plug them in and let the battery charge and then use them wirelessly until it's time to charge again
Thermal
They heat the cold coolant from engine's block to 160° F in as little as one hour, then pump it back to the vehicle's engine and heat exchangers. The result: engine is preheated and the vehicle's heat exchangers distribute an abundance of heat to the vehicle's interior.
a recipe calls for 1 cup of sugar and 1/2 cup of flour.Zoe uses 1 cup of salt and 1/2 cup of flour.
which kind of mutation is best modeled by zoes version of the recipe
Answer:
Substitution
Explanation:
Given the information in the question substitution seems like the most appropriate answer. Zoe used 1 cup of slat rather than 1 cup of sugar, she substituted sugar for salt.
Insertion is wrong because Zoe did not add another ingredient, there is still only 2 ingredients.
Transition is wrong because, given the information, because the state(liquid or solid) of the ingredients has not changed. Zoe is still use dry ingredients per say.
And beneficial also seems to be wrong because we don't know if using salt instead was beneficial to the recipe or to Zoe.
Explanation:
Answer: Subsitution
Explanation: i took the quiz
What does "reliably" mean in these sentences?
Answer:
it would be the top right one
Answer:
in a way that can be trusted
Explanation:
hope this helps!
(no reporting nor deleting this.)
Which of these is a characteristic of body cells that require large amounts of energy?
answers:
They have a large number of mitochondria.
They have a large number of vacuoles.
They have a small number of chloroplasts.
They have a small number of mitochondria.
Answer:They have a large number of mitochondria.
what are the three age categories labels between childhood and adulthood
Answer: Early adolescence, middle adolescence, and late adolescence.
brainliest or a thank you please :)) <33
How many chromosomes are in the cells after they divide? How many chromatids are there?
Answer:
two chromatids
After DNA replication, each chromosome now consists of two physically attached sister chromatids. After chromosome condensation, the chromosomes condense to form compact structures (still made up of two chromatids). As a cell prepares to divide, it must make a copy of each of its chromosomes.
Explanation:
hope it help to you:)
8. Which set of chromosomes represents a mutation? *
8 points
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Answer:
8 points
111!
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what can a negative consequence of humans being hunter-gatherers?
A. they needed to stay in one location for food
B. Nate cultivated their own food
C. they had to move around to find food
D. they had to have large families to help on the farm
Answer:
C
Explanation:
Describe the difference between primary succession and secondary succession. (Be sure to use the vocabulary terms: climax community and pioneer species in your description. Also include a general
time frame for each event)
Answer:
Explanation: Primary means that it was from thAT TIME PERIOD AND SECONDARY MEANS YEARS AFTER THAT TIme period.
How does air pollution affect human health?
a. Respiratory infections
b. Lung Cancer
c. Asthma
d. All of the Above
Answer:
The answer for this question is D
can someone plzz help me on this question its hard :( and i want to pass
Answer: A
Explanation:
Your welcome