Answer the following questions in complete sentences in the space provided:

1. Why does cell division take place in single-celled organisms?

2. What occurs in a cell when it is not undergoing cell division?

3. How do chromosomes change before cell division?

4. What is mitosis?

5. Why doesn’t mitosis occur in prokaryotes?

6. What would happen if DNA did not duplicate during interphase?

7. What is cytokinesis and when does it happen?

8. During what phase of mitosis do the chromosomes line up?

9. When do the chromosomes condense and become visible under a microscope? 10. What happens to the chromosomes during anaphase?

11. Sometimes a cell inaccurately duplicated its DNA, and the resulting cells are not identical. What effects might such a change have on the organism?

Answer:

1.All multicellular organisms use cell division for growth and the maintenance and repair of cells and tissues. Cell division is tightly regulated because the occasional failure of regulation can have life-threatening consequences. Single-celled organisms use cell division as their method of reproduction.

2.What happens to cells that "decide" not to divide? If the decision is to not divide, the cell goes into a quiescent, or nondividing state, called G0 (G zero).

3.Prophase is the first phase of mitosis. During this phase, the chromosomes inside the cell's nucleus condense and form tight structures. In fact, the chromosomes become so dense that they appear as curvy, dark lines when viewed under a microscope (Figure 1).

4.Mitosis is a process where a single cell divides into two identical daughter cells (cell division).

5.In bacterial cells, the genome consists of a single, circular DNA chromosome; therefore, the process of cell division is simplified. Mitosis is unnecessary because there is no nucleus or multiple chromosomes. This type of cell division is called binary fission.

6.If a cell has not properly copied its chromosomes or there is damage to the DNA, the CDK will not activate the S phase cyclin and the cell will not progress to the G2 phase. The cell will remain in S phase until the chromosomes are properly copied, or the cell will undergo programmed cell death.

7.Cytokinesisis the part of the cell division process during which the cytoplasm of a single eukaryotic cell divides into two daughter cells. Cytoplasmic division begins during or after the late stages of nuclear division in mitosis and meiosis.

8.Metaphase. Chromosomes line up at the metaphase plate, under tension from the mitotic spindle. The two sister chromatids of each chromosome are captured by microtubules from opposite spindle poles. In metaphase, the spindle has captured all the chromosomes and lined them up at the middle of the cell, ready to divide.

9.During prophase, the complex of DNA and proteins contained in the nucleus, known as chromatin, condenses. The chromatin coils and becomes increasingly compact, resulting in the formation of visible chromosomes.

11.When Replication Errors Become Mutations. Incorrectly paired nucleotides that still remain following mismatch repair become permanent mutations after the next cell division. This is because once such mistakes are established, the cell no longer recognizes them as errors.

Which of these statements best describes the connection between biodiversity and evolution?
The more biodiversity an area has, the greater the chances of new species arising.
If biodiversity is high, then more predation will take place, preventing species from evolving,
Without a lot of biodiversity, organisms are more likely to survive, so they have more time to adapt.
Evolution depends upon low biodiversity to keep population sizes down, which increases numbers of genes.

The population size of organisms in an ecosystem is based on a variety of limiting factors. The graph
below shows how a rabbit population changed in size over a five-year time period.



Based on the information in the graph, what is the maximum number of rabbits that can obtain
what they need to survive in this ecosystem?



A.about 35

B.about 10

C.about 5

D.about 25

The Sun seems to move across the sky each day because of the rotation of the Earth on its axis. The Sun's path across the sky also appears to change over the different seasons of the year.

Why does the Sun's path change over the different seasons?
A.
because the Earth is tilted and revolving around the Sun
B.
because the Sun is tilted and rotates around its axis
C.
because the Sun is tilted and revolving around the Earth

Which statement explains why secondary succession is generally more rapid than primary succession?
An area of secondary succession has never been colonized.
There are no competing organisms in secondary succession.
The soil is already present at the start of secondary succession.
Pioneer species in secondary succession include bacteria.

Someone help me please!

Cell Wall Functions:
1.Structure and protection
2.Organizes DNA
3.Digests, recycles materials
4.all of the above

HEy please help me..with number 3

The hypothesis that the continents once formed a single landmass, broke up and drifted to their present location is either:
Pangaea
Evolution
Atomic
Continental Drift

plz help

first answer (melted rock in the interior of the earth cools after so many years, turns to solid rock. after plates into each other, mountains form due to pressure which brings the rock on the earth's surface. another way is when rocks flow out with lava, the lava cools and hardens into a rock). this is my first answer. Answer about how you think melted rock deep within Earth could change over time. Would you revise your answer now? If so, how? If not, explain why.

PLEASE HELP (THIS IS SCIENCE

what are some traits of an index fossil? what are they used for?

Think about what abiotic factors giraffes and trees both need to survive. The tree and the giraffe are competing over what factor

If you saw a new moon on Sunday, when will you probably see a full moon?
A) on Sunday in one week
B) a week from Friday
C) on Sunday in two weeks
D) on Wednesday in two weeks

Carolus Linnaeus created a classification system (taxonomy) in the 1700's based on what? *

Describe the movement of Earth’s mantle. Explain how convection currents can cause tectonic plates to move.

Which type of molecule speeds up chemical reactions in living things?

Lipid
Nucleic acid
Protein
Water

When geneticists cut genes from one organism and insert them into the DNA sequence of another organism, the process is called

Which characteristic of our solar system is most crucial to support life on Earth?
A.the length of time of earths revolution
B.distance between the earth and sun
C.the distance between the sun and other stars

How can you use the terms of air pressure, air masses, and fonts to describe the formation of a tornado ??

How are convex and concave lenses used?

IF YOU HELP ME I WILL GIVE YOU BRAINLIEST

How might genetically engineered crops help people in harsh climates(15p)

The diagram below shows a food web. The organisms in a food web can be classified based on how they
get the energy they need.




Which organism in this food web is a primary consumer?



A>mouse

B>snake

C.fox

D.hawk

In what direction and with how much net force will the satellite move?

hey help please......

The Titanic was the most
A. vessel
B. luxurious
C. gazed
ship of its kind in 1912.

A scientist lists the characteristics of an organism that he is observing
It is multicellular
It has cell walls made of cellulose,
It makes its own food,
In which of these Kingdoms should the organism be classified?
Animalia
Archaea
Fungi
Plantae

The Classification level that includes the most specific traits is an organism's ______

Which muscle has 3 muscle "heads' or points of origin that is responsible for straightening the arm?

O Abdominals
O Biceps
O Triceps
O Gluteus Maximus​

Scers who search for oss scheuse the smalfossilto describe some of the finds. An example of a transitional fossilis Dimetrodon, which lived 280-265 million years ago. Dimetrodon had alzard-e appearance but had a sale
structurecking out from is back that owed to regulate is body temperature, an ability that is found today in modern warm-blooded mammals. While Dimetrodon swallowed its prey whole like reptiles do it also had different types of teeth, a tratalo
common to which of the best explains how tonalfossils support the theory of evolution?
Transitional fois show rats common to ancestors as well as descendants
Trafo show how the organic characteristics remain the same over time
Tanlos show how individual organism can change their characteristics during their times
Transitional fossils show how populations of past organisms were not able to change their characteristics over time