What is a purine and a pyrimidine? Name them.

Answers

Answer 1

Answer:

Purines and Pyrimidines are nitrogenous bases that make up the two different kinds of nucleotide bases in DNA and RNA. The two-carbon nitrogen ring bases (adenine and guanine) are purines, while the one-carbon nitrogen ring bases (thymine and cytosine) are pyrimidines.

Explanation:


Related Questions

How/why is ecosystem diversity important?

Answers

Answer:

Ecosystem diversity is a type of biodiversity. It is the variation in the ecosystems found in a region or the variation in ecosystems over the whole planet. Biodiversity is important because it clears out our water, changes out climate, and provides us with food.

Explanation:

It clears out water , makes safe climate change and provides everyone with a meal

Independent assortment is the exchange of genetic material between
homologous chromosomes.
True Or False

Answers

Answer:

False

Explanation:

According to Gregor Mendel in his law of INDEPENDENT ASSORTMENT, independent assortment of genes is a phenomenon whereby the segregation of the alleles of one gene into gametes occurs independently of the alleles of another gene i.e. their segregation does not affect/influence one another. Independent assortment occurs in the Metaphase 1 of meiosis 1, where homologous chromosomes randomly align at the equator of the cell. This random orientation of homologous chromosomes determines which chromosome will separate into which gamete.

According to the question, the exchange of genetic material between homologous chromosomes is termed CROSSING-OVER. Crossing over or Recombination occurs during the Prophase I state of meiosis I, where non-sister chromatids of homologous chromosomes exchange a portion of their gene.

Hence, the answer is false because the exchange of genetic material between homologous chromosomes is crossing-over.

Directional selection only occurs in response to naturally occurring events.
Please select the best answer from the choices provided
Тrue
False

Answers

Answer:

False

Explanation:

Directional selection is a force in nature that causes a population to evolve towards one end of a trait spectrum. This change happens gradually and is hard to notice over a short period of time. This change is consistent and constant.

why do lichens and mosses get mostly replaced by larger plant species during succession

Answers

Answer:

Lichens that colonize bare rock secrete acids that break down the rock and start the soil-production process. Also, as lichens die, they provide some organic matter that also contributes to soil. Mosses can then colonize the thin soil; as mosses die, the soil thickens more allowing other hardy species to colonize

Explanation:

Which would a microscope be LEAST useful in studying?
A. spider
B. amoeba
C. bacterium
D. paramecium

Answers

Answer:

A

Explanation:

spiders can be seen with the naked eye

Answer:

A

Explanation:

A spider is large enough to see and observe without a microscope. Bacteria, amoeba and paramecium are all very tiny, and can’t be seen with just our eyes. To see these things, we would need a microscope. Therefore, a microscope would be the least useful when studying A: a spider.

Birds, lizards, and amphibians are very different groups of animals. However, these groups share some qualities that help them survive. Which of the following is an example of such a quality? A. Birds, lizards, and amphibians have fur to keep their bodies warm. B. Birds, lizards, and amphibians produce milk to feed their young. C. Birds, lizards, and amphibians reproduce by laying eggs. D. all of these

Answers

Answer:

The answer is C

Explanation:

Brainliest?

Answer:

C.

Most mammals don't lay eggs, but platypuses do

A. Only mammals have fur

B. Mammals produce milk

D. The first two were wrong

Explanation:

Which form of nitrogen is most abundant on earth? N2 (Atmospheric Nitrogen) NH3 (Ammonia) NO2- (Nitrite) NO3- (Nitrate)

Answers

Answer:

N2 (Atmospheric Nitrogen)

Explanation:

Nitrogen is a chemical element positioned as 7 on the periodic table. Nitrogen is found as a gas in the atmosphere (N2) and constitutes the most part of the air making it the most abundant gas on Earth.

Atmospheric nitrogen (N2) is the most abundant of its form found on Earth. It can be converted to its compound form e.g. nitrates (a plant usable form) by lightning and some bacteria in the soil.

The picture below shows a lead sheet and a lead pipe.
The lead sheet and lead pipe would have

the same mass
the same chemical properties
different crystal structures
different arrangement of atoms

Answers

I’m not too sure but I would say THE SAME CHEMICAL PROPERTIES.

The diet of leaf-cutter ants is principally
a. leaves
b. fungus
c. saliva-coated leaves
d. fungus-treated leaves

Answers

Answer:

it would be B.

Explanation:

Answer:

b. fungus

Explanation:

FIRST PERSON TO ANSWER GETS BRANLYSEST After Hunter drank a glass of milk, sugar levels in his blood increased. This stimulated the hormone insulin to be released. Insulin helped the sugar move from his blood into cells, so his blood sugar levels decreased. Which statement explains what happened next? Positive feedback caused his pancreas to stop secreting insulin. Negative feedback caused his pancreas to stop secreting insulin. Negative feedback caused his pancreas to produce more insulin. Positive feedback caused his pancreas to produce more insulin.

Answers

Answer:

The correct answer B

When the body gets the glucose, the glucose in the blood increase then the hormone insulin is released so that the glucose from the blood can be transferred from blood into the cells of the body.

The release of hormone insulin is a positive feedback.

Once the glucose is transferred into the cells of the body then the negative feedback starts acting that stops the secretion of insulin from the pancreas.

What will happen next is that negative feedback would cause his pancreas to stop secreting insulin.

The maintenance of relatively constant internal body processes depends largely on negative feedback.

Negative feedback mechanisms ensure that setpoints are returned.

Hence, whatever causes setpoints to be breached is reversed or removed totally.

In this case, the continuous secretion of insulin will further lower the blood sugar level and causes the setpoint to be breached further. Thus, the actuator (insulin) has to be removed.

More on negative feedback can be found here:   https://brainly.com/question/15379119?referrer=searchResults

Which cellular process creates energy?

A. The conversion of ADP to ATP

B. The breaking of the chemical bond between the 2nd and 3rd phosphate
molecules in ATP.

C. The breaking of lipid chains.

D. The transportation of ions across the membrane.

Thank you!!​

Answers

Answer:

B. The breaking of the chemical bond between the 2nd and 3rd phosphate

molecules in ATP.

Answer:

The conversion of ADP to ATP if I remember correctly.

1pt Which of the following cells would be produced by meiosis?
A. a heart cell
B. an eye cell
C. a sperm cell
D. a skin cell

Answers

Answer: c

Explanation:

because meiosis produces our sex cells

OPEN ENDED QUESTION
Why is the Cuyahoga River fire an
important event in dealing with water
pollution?

Answers

It showed people to stop dumping trash into the river.

Question 12
Identify and select the the correct vocabulary that correctly describes DNA. Choose ONLY the correct answers, pick 3.

Answers

Answer:

I personally answered:

nucleotides with adenine, guanine, cytosine, or thymine are the monomers

thymine base pairs with adenine

guanine base pairs with cytosine

Explanation:

Why should the United States be concerned about air pollution in china

Answers

Answer:

The United States should be concerned because many of the things they have is manufactured or made in China . Some things like food or things that could be affected by germs or pollution could affect the users of it and make them sick.

Answer:

c. wind carries air pollution

Explanation:

Chargaffs rule states

Answers

Answer:

Isn't the Chargaffs a DNA of a rule state that have to be 1/1 ratio.

Explanation:

The shortest day of the year in Canada happens during _____.

March
September
June
December

can you guys help me asp

Answers

The shortest day of the year in Canada happens during December 21.

it happens in december

9 Light cannot escape the intense gravitational pull of a
black dwarf
red giant
main-sequence stan
black hole

Answers

I think it’s black hole

Which statements describe floods and wildfires? Check all that apply.
(Select all that apply)
A.Both are natural hazards that affect Florida.
B.Both may affect coastal and inland regions.
C.Both are caused by drought conditions.
D.Both are made worse by the presence of muck
E.Both may be caused by thunderstorms.
F.Both may cause property destruction.

Answers

Answer:

A, B, E, F,

Explanation:

The statements that describe floods and wildfires are as follows:

Both are natural hazards that affect Florida.Both may affect coastal and inland regions.Both are made worse by the presence of muck.Both may cause property destruction.

Thus, the correct options are A, B, D, and F.

What is Wildfire?

Wildfire may be defined as an uncontrolled fire that burns in the wildland vegetation, often in rural areas.

Both floods and wildfires are natural hazards that affect both coastal as well as inland regions. Ultimately both cause rapid destruction of property and lives.

Therefore, it is well described above.

To learn more about Floods, refer to the link:

https://brainly.com/question/134213

#SPJ2

Approximately how long ago did our current era begin ? O A. 1 million years OB. 4.5 billion years C. 65 million yearsO O 100, 000 years

Answers

Answer:

C. 65 million years ago

Explanation:

The current locations of the continents and their modern day inhabitants, including humans, can be traced to this period.

Pls vote brainliest :)

What did Mendel's cross-pollination of pea plants prove?


A. Inheritance of certain factors is dependent upon the genetic code.


B. Certain factors are dominant, and other factors are recessive.


C. All the cells in an organism carry the same hereditary factors.


D. Crossing a tall plant with a tall plant will always result in a tall plant.

Answers

Answer:B

Explanation:

Answer: The correct answer is B- Certain factors are dominant, and other factors are recessive. :)

Explanation:

I took the test. I also had to read a lot about Mendel for my science class.

Hope this helps! <3

Why would humans not be able to repair and reproduce without bacteria short summary please helpp

Answers

Bacteria still offers its benefits. Like for example in the digestive system, they help break down food, like plant fibers. They also supply us with vitamins like biotin and Vitamin K.

When a plant does not get enough water its leaves wilt and stomata are
closed to prevent further loss of water through transpiration. This wilting of leaves and closing of stomata is caused by a growth inhibiting hormone. What is the name of this growth inhibiting hormone that causes wilting of
leaves?

• auxin

• gibberelins

• abscisic acid

Answers

I believe it is auxin because that’s what helps the plant grow and works with hormones to stay healthy

Which of the following identifies the most important reason why the percentage of deaths due to infectious diseases dropped from 1970 to 2015?
Group of answer choices

A.The number of people living in poverty fell as nations became increasingly more developed.

B.More people moved into urban areas, and fewer people remained in disease-prone rural areas.

C.More children were immunized against the major infectious diseases.

D. The use of pesticides became increasingly effective at killing biological threats.

Answers

Answer:

A

Explanation:

I choose A people in one hand really have to come together and make this world a strong, better, and brighter place.

How many ATP are generated in the electron transport chain?
O 2
04
O 32
0 36

Answers

Answer:

32

Explanation:

ANSWER: 32






Explanation: took the test in EDG

A large population of green aphids lives in an field and feeds on wild rose plants. What will most likely resut if exposure to insecticides causes mutations in the aphids over
several generations?

Answers

Answer:gene frequencies in the aphids will change

Explanation:

Drag each label to the correct location on the image
Arrange the symbols to form a DNA molecule.
5
3
5
3'

Answers

Answer:

The right answers are mentioned in the picture.

A base pair (bp) is the pairing of two nucleobases located on two complementary strands of DNA or RNA. This pairing is carried out by hydrogen bridges. There are four types of nucleic bases: A-T-C-G, these letters Adenine, Thymine, Cytosine, and Guanine. A with T and C with G.

It is also necessary to take into account the antiparallel character of the DNA strands. If a strand is in the 5 '3' direction, its complete strand is in the 3 '5' direction.

Explanation:

hich of the following organisms receives at least some energy from plants?
A.
coyotes
B.
rabbits
C.
deer
D.
all of these

Answers

Answer: B

Explanation: Coyotes and deer dont really eat plants like that but deer do sometimes so my best bet is B or C. I hope this is helpful!!

How does soil quality affect the characteristics of ecosystems?

Answers

The answer is. Soils play an important role in all of our natural ecological cycles—carbon, nitrogen, oxygen, water and nutrient.A handful of soil can contain billions of different organisms that play a critical role in soil quality to support plant growth.

Many fish in the lake die due to an increase in water temperature. What Limiting Factor is this an
example of? *

A. Competition

B. Predation
C. Temperature
D.Natural Disaster

Answers

Answer:

C, Temperature

Explanation:

Increase in water heat, changes the temperature levels for the water itself, and including that it may be even warmer towards the bottom of the lake.

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