Which part of the earth system contains the air we breathe?

Which of the following can cause a communicable disease?:

schepotkina [342]

the answer is

c. virus

4 0

3 years ago

Captive breeding programs are used to _______.

Roman55 [17]

<span>A breeding program is a program to increase the population of a species so captive breeding programs are used to replenish the wild populations of endangered species which is the answer under A. It's basically what happened to the pandas, they were bred in captivation to ensure that they wouldn't dissapear completely or become extinct.</span>

3 0

3 years ago

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Why does the rate of heart beat increases during exercise?

kherson [118]

During exercises, our muscles needed energy for contractions. The heart pumps more rapidly and more powerfully during this time for a few reasons.

First, more oxygen and nutrients like glucose can be transported to the heart. Muscle cells uses oxygen and glucose for aerobic respiration to generate energy.

Secondly, more carbon dioxide and waste can be transported away from the muscles. Waste products from aerobic respiration includes carbon dioxide or water etc. The faster the heart pumps, the faster the blood gets transported so more waste can be carried away.

Thirdly, lactic acid can be carried away too. When oxygen supply is not enough, the cells undergo anaerobic respiration to generate energy. This type of respiration does not require oxygen, but a waste product called lactic acid is produced. Lactic acid must be carried away from cells because they're harmful. Therefore, the faster the heart pumps, the more lactic acid gets carried away.

Last but not least, heat can be carried away too. Part of the energy generated is turned into heat. Therefore, in order to help us cool down, blood travels fast to carry heat away from the heat generating muscle cells.

5 0

3 years ago

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1.Write the equation for light dependent reaction of photosynthesis

Annette [7]

Answer:

1. The overall chemical equation of the light-dependent reactions is given below:

12 H₂O + 12 NADP+ + 18 ADP + 18 Pi + light and chlorophyll ----> 6 O₂ + 12 NADPH + 18 ATP

2. The overall chemical equation for the light-independent reactions of the Calvin cycle is given below :

3 CO₂+ 6 NADPH + 5 H₂O + 9 ATP → glyceraldehyde-3-phosphate (G3P) + 2 H+ + 6 NADP+ + 9 ADP + 8 Pi

Explanation:

1. The light-dependent reactions convert light energy into chemical energy, producing ATP and NADPH which are used light-independent reactions to drive the synthesis of sugar molecules from inorganic CO₂ and water. Light-dependent reactions takes place in photosystem I and II. Photosystem I and Photosystem II ( PS I and PS II) are the two biochemical systems, active in chloroplasts, that serve as sites of electron transfer reactions in photosynthesis. Energy from sunlight is used to split water which releases electrons and hydrogen atoms which are transferred to NADP+ to produce ATP and NADPH and oxygen is produced as a waste product.

The overall chemical equation of the light-dependent reactions is given below:

12 H₂O + 12 NADP+ + 18 ADP + 18 Pi + light and chlorophyll ----> 6 O₂ + 12 NADPH + 18 ATP. Note that Pi refers to inorganic phosphate

2. The Calvin cycle refers to the light-independent reactions in photosynthesis. It occurs in three stages.

Stage 1 (Carbon fixation): In this first stage of the Calvin cycle, light-independent CO₂ is fixed by enzyme called ribulose bisphosphate carboxylase (RuBisCO) to ribulose bisphosphate (RuBP) to form glyceraldehyde-3-phosphate.

Stage2: ATP and NADPH are used to reduce 3-phosphoglycerate (3-PGA) into glyceraldehyde--phosphate (G3P). ATP and NADPH are used up in the process and are converted to ADP and NADP+, respectively.

Third stage: RuBP is regenerated, which enables the system to prepare for more CO2 to be fixed.

The overall chemical equation for the light-independent reactions of the Calvin cycle is given below :

3 CO₂+ 6 NADPH + 5 H₂O + 9 ATP → glyceraldehyde-3-phosphate (G3P) + 2 H+ + 6 NADP+ + 9 ADP + 8 Pi

6 0

3 years ago

Anyone mind filling this chart in for me? Thanks, i really appreciate it, just put answers below.

nataly862011 [7]

By row:

1 | 2

2 | 4

2n (same as parent) | n (half that of the parent)

Somatic (form body tissue) | Reproductive (form gametes)

5 0

2 years ago