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hoa [83]
2 years ago
8

Normally penetration of the egg by the sperm cell signals the start of the developmental process. What can replace this signal w

hen no sperm are involved?
Biology
1 answer:
padilas [110]2 years ago
8 0

Answer: parthenogenesis (apomixis and automixis)

Explanation: parthenogenesis can be simply defined as a form of asexual reproduction where the developmental process begins i.e egg develop into an embryo without the prior fertilization from sperm cells.

Egg cells or sex cell (oocyte) are reproduced by replications which produces two diploid cells having full complement of chromosomes that is required for the developmental process to begin.

This form of reproduction occurs in plants as well as some lower invertebrates such as anthropods (insects) and some species of aves, amphibians and reptilians.

It should be noted that parthenogenesis doesn't occur in mammals.

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svlad2 [7]

A non scientific question is a question which cannot be proved to be true as no experiment or no data can be gathered from it. Why are roses the best flowers? is an example of  nonscientific question. The answer of this question is subjective and it brings no scientific data. Scientific question on the other hand is a question that may lead to a hypothesis and help us in answering (or figuring out) the reason for some observation.

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Botulinum toxin is produced by Clostridium botulinum, a gram-negative bacterium. The toxin actually consists of 7 related toxins
Bess [88]

Answer:

A. Botulinum toxin possesses a heavy chain and a light chain, each of which takes part in the toxicity. The binding of the protein and its invasion within a nerve cell is permitted by the heavy chain. After the entry is permitted, the light chain functions like a protease and chops proteins, which would usually permit neurotransmitters to discharge out from the cell. This is basically a commotion of exocytosis or the discharging of neurotransmitters.  

The acetylcholine, that is, the obstructed neurotransmitter generally conducts a nerve impulse to a muscle, allowing the muscle to contract. By inhibiting the neurotransmitter, the botulinum toxin results in its distinctive flaccid paralysis.  

B. The small doses of the sterile, purified botulinum toxin when used in a medical setting as an injectable form prevent the release of a chemical known as acetylcholine by the nerve cells, which signal contraction of the muscles. By selectively interfering with the underlying tendency of the muscles to contract, the prevailing frown lines are smoothed out, and in the majority of the cases are almost invisible for a week.  

8 0
3 years ago
During what step the of Central Dogma is Gene Therapy used?
zhenek [66]

The answer is; DNA

The central dogma is DNA- RNA- Protein

Gene therapy involves the replacement of bad genes in the DNA of a human subject with a better gene. A recessive/mutated allele is removed and  a healthy one is inserted. This way, the proper proteins can be produced solving the disease trait. Ultimately, it will not require drugs to treat the disease.


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a mechanism that is effective in maintaining a normal glomerular blood pressure only if the systemic mean arterial pressure rema
rodikova [14]

A mechanism that is effective in maintaining a normal glomerular blood pressure only if the systemic mean arterial pressure remains between 80 and 180 mm hg is called renal autoregulation.

<h3>What is renal autoregulation?</h3>
  • Autoregulation is the inner characteristic of blood vessels present in end organs, like heart, kidney, and mind, by which they dilate or constrict in response to pressure changes, thus help to keep the blood flow generally steady.
  • Usually our body tries to regulate our blood pressure in range of 50 to 150 mm Hg.
  • Regulation of renal blood flow and glomerular blood pressure in kidneys is called renal autoregulation.
  • There are 3 mechanisms of renal blood flow namely myogenic response (MR), tubuloglomerular feedback (TGF) and third mechanism that is independent of TGF but slower than MR.

Learn more about renal autoregulation here:

brainly.com/question/28064114

#SPJ4

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B. Some of the mass escaped as gas

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