To create a knockout mouse, after introducing to ES cells a DNA construct in which a specific gene is mutagenized by the insertion of a drug resistance marker, the cells, that have incorporated the transgene by homologous recombination grow in the presence of the drug and these are injected into a host blastocyst. The correct option is A.
What is biological marker?A biomarker is an objective measure of what is going on in a cell or organism at any given time. Biomarkers can serve as health-related early warning systems.
To create knockout mice, researchers insert artificial DNA into the chromosomes contained in the nuclei of ES cells using one of two methods.
Both methods are performed in vitro, that is, on cultured cells grown in a laboratory setting.
After introducing a DNA construct into ES cells that mutagenizes a specific gene by inserting a drug resistance marker, the cells that have incorporated the transgene via homologous recombination grow in the presence of the drug and are injected into a host blastocyst.
Thus, the correct option is A.
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Why is it more difficult for top carnivores to obtain sufficient energy resources than it is for animals lower on the food chain?
the trophic pyramid is the reason
what the trophic pyramid is: Trophic pyramid, also called an energy pyramid, showing the progression of food energy. The pyramid base contains producers, organisms that make their own food from inorganic substances. All other organisms in the pyramid are consumers
- predators get little energy from the prey they eat so they must consume multiple prey
It is more difficult for top carnivores to obtain sufficient energy resources than it is for animals lower on the food chain because the higher trophic levels have less energy than the lower ones.
The trophic levels of food chainThe food chain is defined as a feeding pathway that consists of similar organisms that are placed in the same trophic levels.
Trophic levels in a food chain are those levels that is occupied by a group of organisms that have a similar feeding mode.
The plants which are the producers are at the lower trophic level while the carnivores are at the higher trophic levels.
The carnivores eats meat from other animals but not plant or plant products which obtain direct energy from sunlight.
Therefore, It is more difficult for top carnivores to obtain sufficient energy resources than it is for animals lower on the food chain because the higher trophic levels have less energy than the lower ones.
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why do you need to take biology in college if your major is Nursing?
Answer:
Because you still have to obtain degree in your nursing
in some flowers, red and white color is codominant. Flowers and be red ( RR), white (rr) or pink (Rr) if two pink flowers are crossed! what percentage of the offspring will also be pink ?
Answer:
50%
Explanation:
If you do a punnet square you get 1 RR: 2 Rr: 1rr
2. How does temperature change in the troposphere?
A. It increases with height.
B. It decreases with height.
C. It increases and then decreases with height.
Answer:
OPTION-A IS CORRECT
IT INCREASES WITH HEIGHT
Explanation:
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To start an action potential moving down the axon, what must happen?
Answer:
Different ions cross the neuron membrane and stimulus causes sodium channels to open I think.
HELP WITH THESE ASAP NO LINKS PLS
16. should be B) Chemical Properties of Water.
Because those are all examples of chemical changes of water.
17. should be B) The liquid will remain a liquid.
Because 52° C is the same as 125.6° F.
What does the red at the beginning of the video represent? What does this mean about the landscape around Mount St. Helens before 1980?
Answer:
On May 18, 1980, an earthquake struck below the north face of Mount St. Helens in Washington state, triggering the largest landslide in recorded history and a major volcanic eruption that scattered ash across a dozen states
Explanation:
If an object is stationary, it means....
A) There are balanced forces acting on the object
B) There are unbalanced forces acting on the object
C) The object is in motion
D) The object is experiencing air resistance
3. Two body systems work together to help remove waste products from blood. What
are these two systems?
a. Respiratory and excretory
b. skeletal and digestive
c. circulatory and reproductive
d. nervous and excretory
The human body is made up of several organ systems that work as a unit to allow the body to function properly. When the body is invaded by the E. coli bacteria from ingesting undercooked meat, a person will likely experience diarrhea, nausea, and vomiting. Which of the following system failed to do its job?
(I’ll give brainliest)
A. Digestive System
B. Excretory System
C. Nervous System
D. Immune System
The fossil presence of anatomically modern humans in ________ demonstrates that our ancestors were capable of substantial water crossings by 40,000 years ago.
Answer:
The correct answer is - Africa.
Explanation:
Scientists found the fossils of modern humans called Mota an ancient man who lived around 40000 to 45000 years ago in Ethiopia. It was the first DNA isolated from Africa.
This DNA sample says that the Europeans have 6% of the DNA of this modern human, which suggests that there was substantial migration of people into Africa from Europe and the middle east by water crossings.
cuál es el límite entre la cavidad torácica y abdominal?
Answer:
El diafragma es un músculo en forma de cúpula que separa la cavidad torácica (pulmones y corazón) de la cavidad abdominal (intestinos, estómago, hígado, etc.).
Explanation:
Purple flowers are a dominant trait while white flowers are a recessive trait.
Explain what this difference means in terms of the alleles for flower colour.
Answer:
the dominant trait will always over role
what hereditary factors affect ones growths
Auxins cause cells to grow ___. A. Longer on the sunny side of the stem. B. Shorter on the sunny side of the stem . C.shorter on the shaded side of the stem .d. Longer on the shades side of the stem
Answer:
D. Longer on the shaded side of the stem
Explanation:
Auxin is a plant hormone that promotes cell growth and elongation in plant stems.
It causes the cells to grow longer on the shaded side of the stem.
This growth allows for the plant to grow in the direction of the light source it has.
So, the correct answer is D. Longer on the shaded side of the stem
What processes and what form is carbon released from all organisms?
how energy transformations involved in photosynthesis are related to energy transformation involved in cellular respiration
Answer:
Photosynthesis is the process by which energy is converted to chemical energy in plant cells. In cellular respiration plants use the chemical energy stored during photosynthesis in basic life processes. During both photosynthesis and cellular respiration, energy is converted.
Explanation:
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The relationship between the remora and the shark is an example of - (5.5)
A predation
B commensalism
C parasitism
D mutualism
Drag a number and symbol to represent the amount of time Carl worked on problems.
___ ___ ____
Answer:
25 - m
Explanation:
If Carl worked m less than 25, 25 - m would represent the amount of time Davis worked minus the difference in the amount of time that he and Carl worked, which would equal the amount of time Carl worked.
Explain the advantages to a plant of having its cell membranes surrounded by cell walls
Answer:
Advantage of cell walls
It protect and support the cell .
To give difinite shape for the cell.
Having cell walls surrounding cell membranes provides several advantages to plants, including structural support, protection against pathogens, regulation of water balance, and prevention of cell rupture.
The cell wall is a rigid structure located outside the cell membrane in plant cells. It is composed primarily of cellulose, a complex carbohydrate. Here are the advantages of having cell walls:
Structural Support: Cell walls provide mechanical support to plant cells and help maintain the overall shape and structure of the plant. They allow plants to stand upright and withstand environmental forces such as wind or gravity. The cell walls of adjacent plant cells are interconnected, forming a strong network that provides stability to the plant as a whole.
Pathogen Protection: The cell wall acts as a physical barrier against pathogens such as bacteria and fungi. It prevents the entry of pathogens into the plant cells, reducing the risk of infection. Additionally, the cell wall can contain antimicrobial compounds and other defense molecules that provide further protection against pathogens.
Water Regulation: The cell wall plays a crucial role in regulating water balance within plant cells. It helps maintain turgor pressure, which is essential for cell expansion and overall plant growth. The cell wall allows water to enter and exit the cell in a controlled manner, preventing excessive water uptake or loss.
Cell Rupture Prevention: The rigid cell wall helps prevent cell rupture or bursting when the internal pressure within the cell increases. It provides strength and stability to the cell, allowing it to withstand internal pressure changes without bursting.
Overall, the presence of cell walls in plant cells offers significant advantages in terms of structural support, protection against pathogens, regulation of water balance, and prevention of cell rupture. These advantages contribute to the overall health, growth, and survival of plants in diverse environmental conditions.
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A metamorphic rock is a rock that has been
Answer:
The answer is B.Changed from it's original state.
Answer: B. Changed from its original state
Explanation: Metamorphic rocks are rocks that change form.
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Is a fish a living organism?????????????????????????
Answer:
yes a fish is a living organism
Answer:
yes
Explanation:
it can move, eat and produce
A pair of identical twins develop leukemias, where immature white blood cells proliferate uncontrollably. In each case, the cancer cells analyzed from identical twins displayed an identical chromosomal mutation and this critical mutation was not found in the twins normal cells. The twins developed leukemia at different times in their lives. What is the best explanation for the origin of this chromosomal mutation
Answer:
The chromosomal rearrangement resulted from a rare somatic mutational event that occurred in utero
Explanation:
Leukemia is a progressive type of cancer where immature white blood cells (leukocytes) proliferate uncontrollably. Next-generation sequencing (NGS) technologies have shown that somatic mutations are relatively common in different types of leukemia such as, for example, acute myeloid leukemia (AML). Moreover, identical twins are developed from one fertilized egg (ovum) that splits and develops into two identical individuals that share all of their genes (i.e., they have exactly the same genetic information). In this case, it is expected that leukemogenesis was initiated in the utero by the occurrence of a chromosomal rearrangement and proceeded early during development as distinct clonalities. In addition, the fact that identical twins developed leukemia at different times in their lives also indicates that this malignancy wasn't caused by only one mutation, but instead it was triggered by multiple mutational events (i.e., leukemia is a multistep cancer caused by secondary genetic changes).
Which of the following statements best describes what happens during exercise?
(Please explain why each of the incorrect statements are wrong. Thank you!)
A.
Blood vessels in the muscles dilate to increase blood flow.
B.
Blood vessels in the heart dilate to increase blood pressure.
C.
Blood vessels in the organs dilate to increase blood oxygen.
D.
Blood vessels in the lungs dilate to increase blood volume.
Flora y fauna y en clima frio??
Answer:
Explanation:
no entiendo
You put a cat in an open cage with cat food, water, and a litter box (where the cat poops and urinates). The cage cat water food litter box weighs 2000 grams. Two weeks later, the cat has eaten all the food, has drunk all the water, and has grown a little bit bigger. The cat's waste (urine and poop) is still in the litter box. How much would you expect the cage cat litter box with poop and urine to weigh now
Answer:
it would weigh more than before
Explanation:
From this diagram of fossils (sorry it’s a bit blurry) which layer is the youngest and which layer is the oldest? How do you know?
Answer:
The bottom layer is the oldest, and the top layer is the youngest
Explanation:
As time goes on more and more sediment gets piled onto a certain place, meaning the oldest fossils will keep getting deeper and deeper
Which of the following defines an ecological succession
Answer:Ecological succession is the process that describes how the structure of a biological community (that is, an interacting group of various species in a desert, forest, grassland, marine environment, and so on) changes over time. The structure of this community becomes more complex as new species arrive on the scene.
Explanation:
A child falls off a bike and skins a knee. Which systems work together to heal the wound?
O Integumentary, Immune, and Circulatory
Respiratory, Immune, and Digestive
O Integumentary, Immune, and Excretory
O Nervous, Immune, and Endocrine
Answer:
A
Explanation: