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3 years ago

What is electrophoresis? Why does it allow scientists to separate pieces of DNA?

1 answer:

8 0

Genetic fingerprinting – the analysis of DNA in order to identify the individual from which the DNA was taken to establish the genetic relatedness of individuals. It is now commonly used in forensic science (for example to identify someone from a blood sample) and to determine whether individuals of endangered species in captivity have been bred or captured from the wild.
•DNA sequencing – the determination of the precise sequence of nucleotides in a sample of DNA or even a whole genome e.g. the Human Genome Project. 

The process of electrophoresis: 
DNA is chopped, close to the VNTR regions, into fragments using restriction enzymes. The DNA fragments are placed on the agarose gel and a direct current is applied continuously to the gel. The DNA fragments are attracted to the anode. The shorter the fragment, the faster it moves. 
The fragments are transferred onto an absorbent paper placed on top of the gel. The paper is heated to separate the 2 strands in each DNA molecule. Complementary probes which have a radioactive phosphorus isotope are and this pair up with the DNA strands. The paper is placed on an X-ray film and the film goes dark due to radiation emitted by the probes. Now we end up with a pattern of dark stripes on the film matching the positions reached by the fragments in the agarose gel.

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Kohlberg asked subjects to explain how they would respond to moral dilemmas true or false

Alona [7]

Answer:

The correct answer is - True statement.

Explanation:

Kohlberg supported the theory of Piaget's theory of moral development and studied further and asked the question to the different age groups related to the moral dilemma.

Kohlberg was mainly interested in the reason behind the decision related to the moral dilemma than they are right or wrong. He found that logic of reasons tends to change with an increase in age.

Thus, the correct answer is option - true.

8 0

3 years ago

Match the bacterial shape with its description

slega [8]

Answer:(A) a cylindrical shaped bacteria exhibiting a variety of rod shapes.- pleomorphic.

B) A bend, or 'coma shapped' rod - Vibrio.

C) Long, curved, flexible rod - spirochete.

D) Long, curved rod - Spirillum.

E) A small, cylindrical shaped bacteria with a cocci appearance - coccobacillus.

F) Cylindrical shape - Rods.

G) Round shape - Coccus.

Explanation:

A). A pleomorphic bacteria is the one which is capable of changing it's shape, mode of nutrition and reproduction.

B). Vibrio is the genus of gram-negative bacteria. It posses a curved comma shape. This is responsible for foodborne infections.

C). Spirochete is a helical, rod shaped bacteria. It posses flexible cell wall and a mechanism that helps in motility.

D). Sprillium is a gram-negative bacteria. It has a rigid spiral structure. It has a long curved rod. It is found in the stagnant water and can also be responsible for causing water borne diseases.

E). Coccobacillus is a bacteria which has shape which is in between cocci and rod. These are very short rods which are mistakenly consider as cocci.

F). A bacillus or bacilliform bacteria is a rod shaped bacteria which can be found in different taxonomic groups of bacteria. These have cylindrical shape.

G) A coccus is the shape of the bacteria which can be consider as either spherical, ovoid or round in shape.

6 0

3 years ago

Help me to answer this

lidiya [134]

Answer:

Explanation:

No I don't think so because there are animals who live there and he shouldn't destroy their habitat

5 0

2 years ago

A phenotypic ratio for a dihybrid cross is predicted to be 9:3:3:1. The experimental values are:

Maslowich

Two traits that we are examining are the color (purple/white) and the smoothness.
In our sample, we have 135 individuals ( 75 +28+24+8= 135).

Since we know that expected ratio of a dihybrid cross, is 9:3:3:1 we can calculate what is the expected values of each phenotype is.

So, for the white wrinkled phenotype, we expect that there will be one-sixteenth of the whole sample ( there are 16 parts of the whole sample 9+3+3+1=16).
So, we multiply the whole sample- 135 with one-sixteenth (or 0.0625) and get 8,4375.
When you calculate the values for all phenotypes you get results shown in the attached excel table.
When you have your expected and experimental values you compare them with a chi-square test. (The test determines if the difference between the expected and experimental results is statistically significant).

4 0

3 years ago

Read 2 more answers

The student who caught the cold caused by this specific Rhinovirus was exposed to the exact same Rhinovirus 18 months later. Wha

Ilya [14]

The student who caught the cold caused by this specific Rhinovirus was exposed to the exact same Rhinovirus 18 months later. Memory B cells of the immune system will protect her from getting the same cold again.

In immunology, a memory B cell (MBC) is a type of B lymphocyte that forms part of the adaptive immune system. These cells develop within germinal centres of the secondary lymphoid organs.

Memory B cells circulate in the blood stream in a quiescent state, sometimes for decades. Their function is to memorize the characteristics of the antigen that activated their parent B cell during initial infection such that if the memory B cell later encounters the same antigen, it triggers an accelerated and robust secondary immune response.

Memory B cells have B cell receptors (BCRs) on their cell membrane, identical to the one on their parent cell, that allow them to recognize antigen and mount a specific antibody response.

Learn more about memory B cell here : brainly.com/question/23423029

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8 0

2 years ago