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1 year ago

7

Microscopic examination of an animal cell reveals the presence of a plasma membrane but no cell wall. Which additional structure

s would normally be present within this cell?

1 answer:

iragen [17]1 year ago

5 0

Answer:

turttunn

Explanation:

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(c) Based on the data in Table 1, describe why the dominant alleles for body color and wing shape are the alleles that produce a

Brrunno [24]

Answer:

Check the explanation

Explanation:

Consider the below table of F2 data of phenotypic flies: we can reconstruct the table as seen in the second attached image below:

From the above observations it is clear the Gray body long wings and Ebony body vestigial wings are the parental combinations and that the Gray body vestigial wings and Ebony body long wings are the recombinants.

Also the ratio indicates that Gray body is dominant over ebony body and that long wings is dominant over vestigial wings.

here the genes for the two characters have shown independent assortment which means that the genes are unlinked if located on the same chromosome or are located on different chromosomes.

Now F1 hybrid= GgLl (G for Grey and L for Long)

Cross between F1 hybrid and true breeding Gray vestigial (GGll)

GgLl x GG ll

Gametes-----------> GL Gl gL gl Gl

GL Gl gL gl

Gl GGLl GGll GgLl Ggll

(Gray long) (Gray vestigial) (gray Long) (Gray vestigial)

Therefore the probability of getting the flies with gray body vestigial wings= 2/4= 50%

b) The reason why the students obtained the above given F2 results involving a cross between true breeding Gray body and long wings with true breeding Ebony body and vestigial wings is that the genes for the two charcters asssort independently in F2 generation and that the genes are not linked as:

Parents------------------> GGLL x ggll

Gametes -----------------> GL gl

F1---------------------> GgLl (Gray long but in heterozous condition)

Now GgLl x GgLl

Gametes GL Gl gL gl GL Gl gL gl

Here gametes assorted independently and hence in F2 generation we got the above results (U can show the results in the form of punnett square.

4 0

2 years ago

Which of the following is often provided by anthropologists and biologists as a possible explanation for the development of bipe

Lerok [7]

Answer:

C. Standing upright allowed for sightlines over tall grasses and savanna shrubbery

Explanation:

One of the most accepted theories about the development of bipedalism of the hominids is that it was mostly because of the tall grasses and shrubs, so standing upright was providing them with better view. Once the environment changed, and the tropical rainforest was turned into savanna, the hominid ancestors had to adapt in order to survive. Being helpless against the large predators, they needed something in order to be able to detect them from bigger distance so that they can avoid them. The solution seemed to be to be able to see above the tall grasses and shrubs, which meant that they started to use their legs more and more in order to stand up taller. This gradually led to better development of legs for upright standing and walking, also causing changes in the structure of the body, providing the hominids with an adaptation that enabled them to survive in the very dangerous environment.

3 0

1 year ago

Read 2 more answers

What's the primary reason that mammals and avian dinosaurs thrived in the Paleogene period? A. Plants developed as the main food

antoniya [11.8K]

Answer:

I think that it might be A

Explanation:

4 0

2 years ago

Read 2 more answers

Drag each tile to the correct box. The flu vaccine activates adaptive immunity. How does this occur? Antibodies are quickly prod

mestny [16]

Answer:

The correct order would be:

A vaccine introduces a weakened flu virus into the body.

↓

The immune system identifies antigens on the weakened flu virus.

↓

Antibodies are produced, which bind to the weakened flu virus and signal immune cells to destroy it.

↓

The actual flu virus enters the body, and lymphocytes recognize the antigens.

↓

Antibodies are quickly produced and allow the body to fight off the infection.

Vaccination or immunization is the process which helps in developing the immunity (adaptive) against a particular pathogen or microorganism.

It includes the administration of antigen, weakened or heat-killed microorganism (such as flu virus) into the patients body. Body's immune system produces naive B and T cells to eliminate the antigen.

This encounter enables the immune system to produce memory B and T cells against that particular pathogen.

In future, whenever the same antigen enters the body, the immune system gets activated quickly due to the presence of memory cells. It enables the body to produce more effective secondary response against the pathogen.

8 0

2 years ago

Read 2 more answers

Which phrases correspond to "spontaneous generation?"?

vova2212 [387]

Answer:

2 & 4

Explanation:

The theory of spontaneous generation stipulated that life emanated spontaneously from ‘nothing’. This was believed to be true until Francesco Redi & Luis Pasteur later falsified this theory using an experiment. He had two plates of cooked meat. He covered one with a glass bowl and left the other open. The plate with a bowl did not develop maggots while the open one did. This showed that maggot was as a result of hatched eggs that were deposited by flies. Life, therefore, emanates from life.

4 0

2 years ago

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