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3 years ago

What important event in animal evolution marks the beginning of the Cambrian period?

Biology

1 answer:

Alenkinab [10]3 years ago

3 0

The appearance of fossils would the the answer.

Although there has been some scientific debate about what fossil strata should mark the beginning of this period, the "International Geological Congress" determined that the Cambrian period was approximately 543 million years ago of which the first appearance in the fossil record of worms that made horizontal burrows was discovered.

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Identify all the amino acid-specifying codons where a point mutation (a single base change) could generate a nonsense codon.

Murrr4er [49]

Answer:

Glutamic Acid (Glu): codons GAA, GAG

Glutamine (Gln): codons CAA, CAG.

Lysine (Lys): codons AAA, AAG, UCG

Serine (Ser): codons UCA, UCG

Leucine (Leu): codons UUG, UUA

Tyrosine (Tyr): codons UAC, UAU

Tryoptophan (Trp): codon UGG

Arginine (Arg): codons CGA, AGA

Glycine (Gly): codon GGA

Cysteine (Cys): codon UGU

Explanation:

Non sense codons are: UAA, UAG, UGA. Then following the genetic code (see attached file) a single base substitution in any of the codons indicated in the answer could generate a stop codon. This single base substitution might happen in the first, second or third base of the codon.

7 0

3 years ago

The cookie cutter shark feeds by taking a bite of flesh out of whales and large fish. The shark does not kill the larger fish it

uranmaximum [27]

Predator bc it's still feeding on it

6 0

3 years ago

ANYONE FROM UTTARAKHAND

alekssr [168]

Answer:

Nopeeeeeeee...

3 0

2 years ago

If you wanted to design an artificial hormone who's action on a target cell required the least amount of interaction with that c

vitfil [10]

Answer:

The water soluble hormones affect the target cells with least amount of interaction.

Explanation:

Hormones are the chemical messengers. These are the substances secreted by the endocrine glands. The hormones are secreted directly into the bloodstream and are carried to the target cells within the blood only.

Based on their structure, hormones are water-soluble or lipid-soluble. The lipid-soluble hormones are steroid hormones and thyroid hormones. These hormones can easily pass through the lipid bilayer of the cell membrane of the target cell. Therefore, the lipid-soluble hormones have intracellular receptors that are present in either cytoplasm or the nucleus of the target cells.

On the other hand, the water-soluble hormones can not pass through the lipid bilayer of the target cells. Therefore, these hormones have extracellular receptors on the surface of the target cells. Binding of the water-soluble hormones to their cell surface receptors triggers the production of the intracellular second messengers that finally carry the signal to the target protein or any other target molecule.

<u>Therefore, a water-soluble hormone exhibits the least amount of interaction with the target cell. Amine hormones such as epinephrine and melatonin, peptide hormones such as oxytocin are some examples of the water-soluble hormones. </u>

8 0

2 years ago

Cells that do not divide are described as being in the ____ phase.

KengaRu [80]

Answer:

The G0 Phase

Hope this helps!!

3 0

3 years ago