Speciation without geographic isolation is called _______

Which of the folowing explain why sterols(or steriods) are considered to be lipids

taurus [48]

They are hydrophobic and insoluble in water

6 0

2 years ago

Provide evidence to reject this statement, "Human phenotypes are usually a clear cut either situation"

tensa zangetsu [6.8K]

Wavy hair is a very easy example that this is false. It's a merge between straight and curly hair. Our traits tend to mix and blend together, it's not so simple. Everybody isn't just tall or short, one or the other. Everybody is a different height because it's a mid between your parents.

8 0

3 years ago

Read 2 more answers

imagine a cell-surface receptor protein is being newly synthesized. How can it get into the membrane that it will ultimately be

motikmotik

Answer:

the steps for a new receptor synthesis:

Explanation:

Do not forget the steps vary from an eukarityc cell to prokarityc one.

IN AN EUKARYOTIC CELL:

1- Transcription: in the nucleus, mRNA is synthesized from the DNA sequence that codifies the protein. Exons are spliced if needed by spliceosomes.

2- From nucleus into cytoplasm: mRNA goes through nuclear membrane into the cytoplasm were ribosomes, substrates for protein synthesis and other organelles are.

3- Ribosomes recognize a signal in mRNA and start reading the genetic code, three consecutive nucleotides at a time and adjust the correspondent tRNAs (tRNAs carry the aminoacids)

4- Peptide bonds are formed between consecutives aminoacids, and a polypeptide is build up according to the mRNA sequence.

5- (The mRNA has a signal that is recognized by the rough endoplasmic reticulum) The peptide goes into this reticulum (RER) and then into Golgi apparatus. (more chemical modifications are made if needed). By this moment the protein has an inserted portion in a lipid membrane.

6- The protein is transported in a vessel that finally fusions with cytoplasmic membrane and the receptor is in destiny. Hydrophobic aminoacid sequences are inserted in membrane.

IN A PROKARYTIC CELL:

1- Transcription (no splicing is needed, there are not exons)

2- There are not nucleus and cytoplasm divided (no transport)

3- Ribosomes recognize a signal in mRNA and start reading the genetic code, three consecutive nucleotides at a time and adjust the correspondent tRNAs (tRNAs carry the aminoacids)

4- Peptide bonds are formed between consecutives aminoacids, and a polypeptide is build up according to the mRNA sequence.

5- The mRNA has a signal that is guides the growing protein to cellular membrane. Hydrophobic aminoacid sequences are inserted in membrane.

8 0

2 years ago

Bmi provides common language for doctors, dietitians and agencies like insurance companies to use as a method to determine an in

Ganezh [65]

BMI<span> (body mass index), which is based on the height and weight of a person, is an </span>inaccurate<span> measure of body fat content and does </span>not take into account muscle mass, bone density, overall body composition, and racial and sex differences. <span>BMI is a substitute measure of body fatness because it is a measure of excess </span>weight<span> rather than excess body </span>fat<span>. Factors such as age, sex, ethnicity, and muscle mass can influence the relationship between BMI and body </span>fat<span>.</span>

6 0

2 years ago

What part of the female system is the usual site of fertilization of the ovulated oocyte?.

Paul [167]

Fertilization of the egg cell by the sperm usually takes place in the fallopian tube. The fertilized egg then travels to the uterus and implants in the endometrium.

<h3>What are fallopian tubes?</h3>

Fallopian tubes are also called oviducts or uterine tubes. It is the passage through which the egg enters the uterine cavity from the ovary.
Fallopian tubes are part of the reproductive tract. They have a smooth muscle wall, an inner mucous membrane, and an outer layer of loose supporting tissue (serosa).

<h3>Why does fertilization take place in the fallopian tubes?</h3>

The fallopian tube (oviduct) regulates fertilization through sperm induction and sperm hyperactivity. Sperm induction is achieved by rheotaxis, thermotaxis, and chemotaxis. Rheotaxis is caused by tubal fluid that creates a current flow from the tubal ampulla to the tubal isthmus.

To learn more about fallopian tubes visit:

brainly.com/question/12711470

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8 0

1 year ago

Speciation without geographic isolation is called ________ speciation.