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topjm [15]
3 years ago
7

When do scientists believe life originated on Earth?

Biology
1 answer:
skad [1K]3 years ago
6 0
A. 3.7 billion years ago
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A newborn baby dies soon after birth because her diaphragm and rib cage muscles failed to contract and she was unable to breathe
kozerog [31]

Answer:

Troponin

Explanation:

This is a complex of three proteins  (Trop C, I, T) that are responsible for muscle contraction of  the skeletal and cardiac  muscles . its binds with protein tropomysin  to lie in the grove between the actin filaments.  its prevents contraction by blocking  myosin crossbridge  in a relax muscles.Inorder to aid contractions  calcium ions binds with troponin, which leads to confrontational change.This exposes myosin on actin filaments,  leading to formation of crossbridge and therefore contraction of muscles.

Therefore if there is  a mutation in the gene that encoded Troponin, as explained above, calcium ion  will not be able to bind with tropinin, and there will be no exposure of myosin on actin filaments, no binding of  myosin on actin to cause crossbridge, and consequently no  muscle contraction,

Thus the intercoastal  muscle and diaphragm will not contract leading to death of the baby.

8 0
3 years ago
Read 2 more answers
Like all cells, the neurons' internal organization dictates its function. Neurons have relatively many mitochondria, an extensiv
4vir4ik [10]

Answer:

Neurons have stable, relatively unchanging internal environments.

Explanation:

Neurons or nerve cells is the structural and functional unit of the nervous system. Neurons consists of the dendrites, axon, cell body and different cell organelles.

The neurons have mitochondria that meets the high ATP requirement and and consume more oxygen. The network of rough endoplasmic reticulum and ribosomes produce large number of proteins in neuron. The internal environment is never stable and gets changed as the nerve impulse transmission occur through the neuron. The membrane potential of the neuron gets changed and changes its internal environment.

Thus, the correct answer is option (B).

5 0
3 years ago
A ________ is a section of DNA that codes for a trait or other functional product.
lisabon 2012 [21]
A gene is a section of DNA that codes for a trait or other functional product so the answer is B. gene :)))
i hope this is helpful 
have a nice day 
6 0
3 years ago
What is the difference between the chemical and physical layers of the earth?
r-ruslan [8.4K]
These layers<span> do not correspond on a one-to-one basis with the </span>compositional layers<span>. The Earth has five mechanic </span>layers<span>: The lithosphere is the outermost mechanical </span>layer<span> and is the most rigid </span>layer<span> of the Earth. The lithosphere consists of the crust, and some of the uppermost mantle.</span>
6 0
3 years ago
What happens in a chloroplast?
Vera_Pavlovna [14]

Answer:

Photosynthesis

Explanation:

The chloroplast creates glucose and oxygen, also the chloroplast has chlorophyll.

8 0
3 years ago
Read 2 more answers
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