1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Mrrafil [7]
2 years ago
9

Telomerase activity may decline with old age and this could explain why cells lose their ability to divide after many replicatio

ns. a. true b. false
Biology
1 answer:
Bumek [7]2 years ago
6 0

It is true that telomerase activity declines with old age which explains why cells lose their ability to divide after many replications.

Telomeres are DNA–protein complexes found at the ends of each chromosome they contain repetitive sequences of DNA. Telomeres protect the genome from nucleic bases degradation, unnecessary recombination, repair, and prevent the fusion of chromosomes. Telomeres, therefore, play a vital role in preserving the information in our genome.

Telomeres shorten with every consecutive DNA replication cycle limiting the number of cell divisions a cell can undergo, Telomeres act as a tumor suppressor by halting the replication of cells which contains several mutations after many division cycles.

To learn more about tumor suppressors here

brainly.com/question/16188646

#SPJ4

You might be interested in
Put these steps in the order in which they occur in light-dependent reactions. Electrons are transferred from photosystem II to
Tamiku [17]

Explanation:

  1. Light energy is absorbed and transferred to the reaction center.
  2. A water molecule is split.
  3. Electrons are transferred from photosystem II to photosystem I.
  4. ATP is synthesized from ADP and inorganic phosphate.

Further Explanation:

Photosynthesis is a chemical pathway that’s integral to producing energy in plants and other primary producers. Energy in the form of molecules of glucose is produced from light, water and carbon dioxide while oxygen is released. This occurs in several complex steps, photosynthesis is a rate limited reaction, depends on several factors including carbon dioxide concentration, ambient temperature and light intensity; the energy is retrieved from photons, I.e. particles of light, and water is used as a reducing agent. This occurs in the thykaloids, where pigment molecules like chlorophyll reside.

The chloroplast is a membrane bound organelle found in plants. It contains several invaginations of  a plasma membrane called the thylakoid membrane. This contains chlorophyll pigments, in stacks called granum, while the internal spaces of the organelle are called the lumen. Liquid surrounds the granum, forming the stroma.

During the light reaction:

  • Light is absorbed by pigments in phosystem II (PSII). This energy is transferred among pigments til it gets to the reaction center, and is transferred to P680; this promotes an electron to a higher energy level where it then goes to an acceptor molecule.
  • Water supplies the chlorophyll in plant cell with replacement electrons for the ones removed from photosystem II. Additionally, water (H2O) split by light during photolysis into H+ and OH- acts as a source of oxygen along with functioning as a reducing agent.
  • the electron moves down an electron transport chain (ti PS I)where it experiences continuous energy loss. This energy fuels the pumping of H+ from the stroma to thykaloid, leading to the formation of a gradient. The H+ move along their gradient and cross through ATP synthase, into the the stroma.
  • ATP synthase converts ADP and Pi to the energy storage molecule  ATP.
  • The electron gets to photosystem I where it  goes to pigments at P700. It absorbs light energy, the electron is promoted to a higher energy level, and passed to an electron acceptor. This leaves a space for another electron which is then replaced by one from photosystem II.
  • in the ETC,  the molecule NADP is reduced to NADPH by providing H+ ions. NADP and NADPH are integral to the Calvin cycle where monosaccharides or sugars like glucose are produced after the modification of several molecules.

Learn more about Photosynthesis at brainly.com/question/4216541

Learn more about cellular life at brainly.com/question/11259903

#LearnWithBrainly

5 0
3 years ago
If I breed a short for FF female with a short for Ff male then I will expect to see what type of offspring
Usimov [2.4K]
If being short is the dominant trait, then you should expect the offspring to also be short.

This is because the traits are spread out as four different possibilities. Either FF, FF, Ff, or Ff. If the dominant trait is being short, “F” then this would mask the recessive trait “f”.
5 0
3 years ago
explain why it is possible to see the detailed structure of a prokaryotic cell with an electron microscope but not with a light
max2010maxim [7]
A microscope is to see smaller things that you can’t see and it is a really good tool.
4 0
3 years ago
All of the following are wastes removed by the kidneys except
pshichka [43]

Answer: water

Explanation:

3 0
3 years ago
19. What are Darwin's four main ideas of natural selection?
vichka [17]
<span>More individuals are produced each generation that can survive.

Phenotypic variation exists among individuals and the variation is heritable.

Those individuals with heritable traits better suited to the environment will survive.
<span>
When reproductive isolation occurs new species will form.</span></span>
7 0
3 years ago
Other questions:
  • How does the anatomy of a female rat differ from that of a human?
    9·1 answer
  • Which body system is responsible for our movement, energy, and for moving food from one organ to another?
    6·1 answer
  • All chordates have _____ (at some point in their life cycle). feathers diaphragm fins pharyngeal pouches
    14·1 answer
  • How are the limbs of the organism pictured above similar?
    9·2 answers
  • Ethnic skin types contain ______ than caucasian skin types.
    11·1 answer
  • This aquatic area is one of the most productive on Earth. More organic matter is created ere each year than comparably-sized are
    15·1 answer
  • Which process releases the greatest amount of ATP
    6·1 answer
  • Consider the virus that has a complex shape ,which organism does this virus infect animal bacteria plants fungi
    14·2 answers
  • what is the concentration where the reaction rate is maximized the active sites of the enzymes are all used adding more substrat
    10·1 answer
  • What are adult stem cells
    10·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!