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3 years ago

7

The mosquito in the amber is an organism preserved over millions of years. This is a perfect example of a ____________________.

(vestigial structure or fossil).

1 answer:

natka813 [3]2 years ago

6 0

Answer: A body fossil

Explanation:

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Is Crohns disease an inherited disorder

stich3 [128]

Answer:

yes it does run in the family

Explanation:

the inheritance pattern of Crohn disease is unclear because many genetic and environmental factors are likely to be involved. However, Crohn disease tends to cluster in families; about 15 percent of affected people have a first-degree relative (such as a parent or sibling) with the disorder.

hope this helps :^)

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3 years ago

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What must happen before meoisis can begin

kotegsom [21]

Answer:

Before meiosis actually begins, the DNA that is packaged into chromosomes must be fully copied.

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One of your lab partners has followed the recommended procedure of running Gram-positive and Gram-negative control organisms on

andreyandreev [35.5K]

Answer:

Reduced in holding time of decolrization step and also used less Alcohol because decolrization step is important in Gram's staining.The decolorization step must be performed carefully. Otherwise over-decolorization may occur. This step is critical and must be timed correctly otherwise the CV stain will be removed from the Gram-positive cells. If the decolorizing agent is applied on the cell for too long time, the Gram-positive organisms to appear Gram-negative..

Explanation:

Gram' staining is a technique used in microbiology labs to differentiate between Gram's positive and negative

<u>Gram-positive bacteria :</u>Stain dark purple due to retaining the primary dye called CV in the cell wall.

<u>:Gram-negative bacteria </u>Stain red or pink due to retaining the counter staining dye called Safranin or neutral red.

There are four basic step in Gram" staining

1) Application of the Primary Stain to a Heat-Fixed Smear of Bacterial Culture

2)Addition of Gram's Iodine

3)<u>Decolorization with 95% Ethyl Alcohol:</u>Alcohol or acetone dissolves the lipid outer membrane of Gram-negative bacteria, thus leaving the peptidoglycan layer exposed and increases the porosity of the cell wall. The CV-I complex is then washed away from the thin peptidoglycan layer, leaving Gram-negative bacteria colorless.

On the other hand, alcohol has a dehydrating effect on the cell walls of Gram-positive bacteria that causes the pores of the cell wall to shrink. The CV-I complex gets tightly bound into the multi-layered, highly cross-linked Gram-positive cell wall thus staining the cells purple.

The decolorization step must be performed carefully. Otherwise over-decolorization may occur. This step is critical and must be timed correctly otherwise the CV stain will be removed from the Gram-positive cells. If the decolorizing agent is applied on the cell for too long time, the Gram-positive organisms to appear Gram-negative. Under-decolorization occurs when the alcohol is not left on long enough to wash out the CV-I complex from the Gram-negative cells, resulting in Gram-negative bacteria to appear Gram-positive.

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3 years ago

What are the mRNA triplets coded for from this gene? A) GGG UUC ACC B) CCC AAG TGG C) GGG TTC ACC D) UUU CCC AGA

vfiekz [6]

Complete question:

A gene on strand of DNA has the following nucleotide sequence: CCCAAGTGG

A) GGG UUC ACC

B) CCC AAG TGG

C) GGG TTC ACC

D) UUU CCC AGA

Explanation:

What are the mRNA triplets coded for from this gene?

A) GGG UUC ACC

RNA codons determine certain amino acids, so the order in which the bases occur within in the codon sequence designates which amino acid is to be made bus with the four RNA nucleotides (Adenine, Guanine, Cysteine and Uracil). Up to 64 codons (with 3 as stop codons) determine amino acid synthesis. The stop codons ( UAG UGA UAA) terminate amino acid/ protein synthesis while the start codon AUG begins protein synthesis.

Further Explanation:

All the genetic information within the eukaryotic cell is stored within the nucleus as helical DNA. This DNA is condensed and tightly wound around histones as chromosomes. Chromosomes within the nucleus is unwound, unzipped and read by enzymes in a complex series of steps known as transcription. The message on DNA, called genes is copied by RNA polymerase, to form mRNA complementary sequence to that of the DNA strand. These are then translated into proteins in ribosomes.

Nucleic acids like DNA stores all of an organism’s genetic information. Nucleic acid molecules comprise the nitrogenous bases Guanine, Adenine, Cytosine and Thymine. Conversely, RNA nucleotides are Adenine, Guanine, Cysteine and Uracil. These pair up as base pairs due to their varied structure- largely influenced by the location of N molecule.

In certain combinations, these bases form codons which act as instructions for protein synthesis. Codons are three nucleotide bases encoding an amino acid or signal at the beginning or end of protein synthesis. Thus, these contribute to the broad diversity of living organisms, as varied combinations of these 64 codons can produce many proteins which can be organized into cells, tissues and organisms.

Learn more about transcription at brainly.com/question/11339456

Learn more about DNA and RNA at brainly.com/question/2416343?source=aid8411316

#LearnWithBrainly

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3 years ago

The hormones that are released by the adrenal cortex and that play a key role in the body's response to long-term stressors are

OLga [1]

Answer:Cortisol
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