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noname [10]
2 years ago
6

1. Single-celled organisms

Biology
1 answer:
Varvara68 [4.7K]2 years ago
5 0

Answer:

A is the correct answer

Explanation:

the existed about 3.8to 4.0 billion years ago

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You have been growing some animal cells in a test tube. The cells grow for several days, then do not appear to grow as well. You
svetlana [45]

Answer:

D. There is no enough oxygen in the culture fluid

Explanation:

The cells in the test tube need to carryout one of the important metabolic processes of living organisms - respiration. The process involves the breakdown of glucose to generate energy for other metabolic processes in the cell.

Respiration can be carried out in the presence of oxygen (aerobic) or in the absence of oxygen (anaerobic). Human cells are primarily aerobic but can carryout respiration anaerobically in the presence of inadequate oxygen.

For aerobic respiration, glucose is broken down in the presence of oxygen to produce carbon-dioxide, water and energy in the form of ATP:

C_6H_1_2O_6 + 6O_2 --> 6CO_2 + 6H_2O + ATP

<em>In the absence of oxygen, the glucose becomes converted to lactic acid and a smaller amount of ATP is produced as compared to aerobic respiration.</em>

<em>Hence, lactic acid gradually builds up in the absence of oxygen due to anaerobic respiration.</em>

The correct option is D.

6 0
3 years ago
Read 2 more answers
According to the central dogma, which of the following represents the flow of genetic information in cells?
const2013 [10]

Answer:

DNA to RNA to protein.

Explanation:

Central dogma in biology was given by Crick in 1957. The central dogma explains the flow of genetic information in the cells.

According to the central dogma, DNA can multiply and increase its number by the process of replication. The information from DNA is changes to RNA by the process of transcription. The expression of protein product expression occur from the RNA by the process of translation. Hence, the information travels from DNA to RNA to protein.

Thus, the correct answer is option (2).

4 0
3 years ago
Name the enzyme that breaks down H2O2.. Anybody know?!?!?!?!
Alborosie
The enzyme that breaks down H2O2 is called catalase.
3 0
2 years ago
The ___ ___ is responsible for maintaining homeostasis within any cell.
dmitriy555 [2]
Cell membrane is responsible 
8 0
3 years ago
Read 2 more answers
The large surface area in the gut directly facilitates _____.
Flura [38]

Answer:

B. Absorption

Explanation:

  • Absorption is a process that takes place in the small intestines or ileum of the GI tract, in which simple and soluble nutrients are absorbed into the blood stream.
  • Absorption is enhanced by several adaptations of the gut such as large surface area of the gut which directly facilitates absorption of nutrients.
  • Presence of villi and microvilli in the gut increases the surface area for absorption of nutrients in the ileum.
6 0
3 years ago
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