Science book which of the following evidence that Earth is a sphere ? choose all that apply

How does the structure of a brain cell related to its function?

lesya [120]

Solution:

Structure dictates function. Ribosomes provide another good example of structure determining function. These small cellular components are made of protein and ribosomal RNA (RNA).Their main function is to translate messenger RNA, or mRNA, into strings of amino acids called proteins.

The structure and shape of each type of human cell depends on what function it will perform in the body. For example, red blood cells (RBCs) are very small, flat discs, which allows them to easily fit through narrow capillaries and around sharp corners in the circulatory system to deliver oxygen throughout the body.

Neurons carry messages from the brain and spinal cord to the rest of the body, using electrical signals down their lengths and chemical signals between neurons. Since electrical signals travel much faster than chemical signals, neurons are long and thin to minimize the number of slower chemical signals that would be required between links in a chain of many shorter neurons.

The elongated shape of muscle cells allows the contraction proteins to line up in an overlapping pattern that makes muscle flexing possible.

And human sperm cells’ structures allow them to “swim” long distances to reach an egg for fertilization. They do this by using flagella, their long whip-like tails, and also by being very small, carrying little more than the DNA for a potential zygote.

This is the required answer.

7 0

3 years ago

DCCD (dicyclohexylcarbodiimide) inhibits oxidative phosphorylation when the substrate is mitochondrial NADH. DCCD is a drug that

VARVARA [1.3K]

Answer:

A) Decreases cellular energy production

B) DCCD also affects K+ transport

Explanation:

A) Consequences are of DCCD on cellular energy production: Decreases cellular energy production

ATP-synthase pump is composed of two subunits: F1 catalytic subunit that synthesizes ATP, and F0 proton pumping subunits, that transport H+ through the membrane. F1 subunit might act independently of F0 to produce ATP, but this molecule can not be released without H+ gradient, which generates a movement necessary for ATP release from the catalytic center.

When any of the parts composing F0 react with DCCD, the subunit can not transport H+ through the membrane. DCCD inhibits the enzyme activity by blocking the protons´ flow.

As DCCD blocks the protons´ flow, and the protons´ flow is necessary to release the ATP molecule from the F1 subunit, no other ADP + Pi can enter to F1 subunit, and the production of ATP stops.

B) Other cellular effects of DCCD

There seem to be other effects of DCCD on cell activity, some of which are still under study. To name a few:

Diimide from DCCD seems to stimulate cytochrome b reduction and inhibits its reoxidation by ferricyanide.
When exposing the cell to high concentrations of DCCD for a long time, might occur an alteration in the electron transporting chain
Inhibition of ubiquinol-cytochrome c reductase activity when exposing the cell to high concentrations of DCCD.
Inhibition of K+ transport, associated with the inhibition of H+ transport.

Concerning the effect of DCCD on the K+ transport, DCCD stops the extrusion of H+ and the consequent intrusion of K+.

DCCD strongly inhibits the simultaneous flow of H+ and K+. First, it inhibits H+ flow, acidification of the environment stops, but at this point, K+ keeps moving through the membrane. Once the H+ flow has ceased, the K+ flow slowly decreases until it finally stops moving. There is a lag time in the DCCD effect on K+ flow to the instantaneous effect on H+ flow.

5 0

3 years ago

As the course of evolution has proceedin plants, what is the overall trend in the relationship of the diploid stage and the hapl

Lostsunrise [7]

Meiosis in simple terms is the process by which gametes (sperm and egg) fuse together to produce a fertilised egg. Haploid is a word that refers to how many chromosomes a certain cell has. In this case the gametes have a haploid number of chromosomes, which is half the number a normal cell has. A normal cell has a diploid number of chromosomes. So in meiosis the two gametes come together with their hapoid number of chromosomes each to create an egg that has a diploid (standard) number of chromosomes.

3 0

3 years ago

Ape species began to dwindle during the Miocene, leaving only a few remaining: a situation that exists up to the present. It is

fiasKO [112]

The change in weather pattern caused forest to become sparse and hot weather caused the reduction of apes as they had less food and difficulty in surviving the climate.

Explanation:

In Miocene epoch volcanic mountain chains were created in Central Africa which abruptly changed the local weather.

The sea-level got drop due to global cooling of that time.

This resulted in continental drift making land connection of Africa with Eurasia.

The primates started migrating through this route.

The African forest become dry causing selective pressures in primates.

The cooler climate in Eurasia caused extinction and migration of primates to Africa in late Miocene epoch.

The hot and humid climate and less woodland caused a reduction in number of apes which were replaced by modern world monkeys.

7 0

3 years ago

Discuss the factors that could fail the process of dough rising (6marks)

Alex Ar [27]

Answer:

The yeast is no longer active, Climate conditions, too much liquid, Wrong type and amount of yeast, Not adding or using too little salt, Insufficient baking time and Wrong oven temperature.

Explanation:

The yeast is no longer active, Climate conditions, too much liquid, Wrong type and amount of yeast, Not adding or using too little salt, Insufficient baking time and Wrong oven temperature are the factors that could fail the process of dough rising. For rising of dough, the environmental conditions and materials that is used in dough must be present in optimum range or quantity.

8 0

2 years ago