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2 years ago

What property of a mineral is being observed when looking for what color is left after scratching it on a ceramic plate?

Biology

1 answer:

lions [1.4K]2 years ago

6 0

Answer:

Streak Test

Explanation:

A streak test is used by geologists to help determine the powdered color of a mineral. They usually use a white or black plate, scrape a sample of the mineral onto the plate, and voila!

P.S. I also had a question like this on a test before.

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What are the differences in their hard parts, distribution, reproduction among phytoplankton of cyanobacteria, diatom, coccolith

Margarita [4]

Answer:

Explanation:

DIFFERENCES BETWEEN HARD BODY PARTS.

•Cyanobacteria have calcified sheaths.

• Diatoms have hard but porous cell wall.

• Coccolithophores have hard body parts.

• Silicoflagellates skeleton is composed of opaline silica.

• Dinoflagellates do not have hard body parts

• Green algae - no hard body parts.

• Brown algae - no hard body parts.

DIFFERENCES BETWEEN DISTRIBUTION

• Cyanobacteria are found almost in every terrestrial habitat on planet.

• Diatoms are found in oceans, freshwater, soil and damp.

• Coccolithophores are exclusively marine.

• Silicoflagellates are found in marine environment.

• Dinoflagellates are both freshwater and marine.

• Green algae grow on objects that do not move such as substrate, rock.

• Brown algae - wide distribution from tropical to polar zones.

DIFFERENCES BETWEEN REPRODUCTION.

• Cyanobacteria - asexually by binary or multiple fission, fragmentation, spore formation.

• Diatom - asexually by cell division through mitosis.

• Coccolithophores - asexually by binary fission.

• Silicoflagellates - asexually

• Dinoflagellates - asexually

• Green algae - sexually or asexually by cell division, fragmentation, spore formation.

• Brown algae - sexually and asexually.

5 0

3 years ago

Is blood clotting an example of a positive or negative feedback mechanism? Explain your answer based on the description of the m

serg [7]

Answer:

Blood clothing is an example of positive feedback.

This type of feedback mechanism is useful to the body because it multiplies the factor that intervenes in clotting accelerating the process.

If a toxin affects the molecules that signal for platelets the feedback will not be effective enough to produce clotting and the body will keep bleeding.

Explanation:

Blood clotting is an example of positive feedback due to the fact that when the vascular endothelium is damaged platelets will go to this area and activate themselves once they are in contact with the collagen fibers of the damaged structure. When the platelets are activated they will release the contents that is stored in their granules. One of the contents is a Gq-linked protein receptor cascade, that will increase the concentration of calcium in the platelets. Calcium activates protein kinase C, which, in turn, activates phospholipase A2 (PLA2). PLA2 will modifies an integrin membrane increasing its affinity to bind fibrinogen. The activated platelets change their shape , and the fibrinogen cross-links with the integrin membrane aiding in the aggregation of adjacent platelets. After this the coagulation cascade takes place. there are two pathways the extrinsic and the extrinsic one.

The extrinsic pathway will be activated due to tissular factor released by the platelets and the intrinsic pathway will be activated due to endothelial collagen. The final product of both pathways is factor x.

Factor x will transform prothrombin into thrombin will activate the conversion of fibrinogen into fibrin. Thrombin will form a net of fibrin that will the clot.

A cascade reaction is useful because every component of the cascade are related making a quick reaction once that one of then is activated and can activate other or more factors.

If a toxin affects the molecules that signals for platelets, platelets will not go to the damaged area and in consequence there will not be thrombin and fibrin to form the clot together with platelets.

7 0

3 years ago

What are components of earths life support system

ludmilkaskok [199]

Answer:

they are rocks, water, air, soil and living things

Explanation:

5 0

3 years ago

Read 2 more answers

Give one real life example of an enzymatic reaction in the human body.

son4ous [18]

Answer:

Enzymes are the bio-catalyst produced by the body.

They increases the rate of bio-chemicals reaction taking inside the body.

They form enzyme-substrate complex in order to increase the rate of the reaction.

They are highly specific in nature.

Example:

Hexokinase catalyses the conversion of glucose to glucose-6-phosphate.

Salivary amylase catalyses the breakdown of starch into maltose (simpler sachharides).
Protein kinase is an enzyme used to activate or deactivate other by adding phosphate group to them.

5 0

3 years ago

Channel proteins facilitate the transport of molecules by active transport.

docker41 [41]

Answer:

b. False

Explanation:

Channel proteins use passive transport, that is, they do not require energy such as ATP for transporting molecules.

8 0

3 years ago