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Aneli [31]
3 years ago
5

Describe the source of free oxygen in the Earth’s early atmosphere

Biology
1 answer:
Zina [86]3 years ago
6 0
Tree's give off oxygen for us to breath
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I believe that local controls are what causes reactive hyperemia to increase tissue perfusion. Reactive hyperemia or venous hyperemia is the transient increase in organ blood flow that occurs following a brief period of ischaemia. 
Tissue perfusion is the decrease in oxygen resulting in the failure to nourish the tissues at the capillary level. Local blood flow regulation involves the rapid control of arterial vasomotion based on the metabolic needs of the surrounding tissues and cells. 
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3 years ago
What are some types of scientists?
Lostsunrise [7]

Answer:

astro,bio,and celluar

Explanation:

there are many diiferent types of scientists

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Which statements apply to laws? Check all that apply.
Nataly [62]

Answer:A law is a factual statement., and A law cannot be changed or replaced.

Explanation: idk cuz i did it -_-

7 0
4 years ago
Read 2 more answers
Which is true of genes?
stepan [7]

Answer:

They are sections of DNA that produce the proteins that control an organism's characteristics.

Explanation:

  • <em><u>Genes are units of heredity found in a certain place on a chromosome and that codes for a certain product.</u></em>
  • A trait of an organism is a characteristic that an organism can pass on to its offspring through its genes .
  • Genes are sections of DNA that contains information which controls a trait. Therefore, a trait depends on genes. Therefore; genes are the sections or segments of DNA that code for a specific trait in organisms.

6 0
3 years ago
Recall that one approach to the study of cell cycle regulation has been to fuse cultured cells that are at different stages of t
nikitadnepr [17]

Answer:

1. T

2. T

3. NP

4. F

5. F

Explanation:

In somatic cells, the cell cycle can be divided into 1-the interphase, 2-the mitotic phase or M phase, and 3-the G₀ phase. In turn, the interphase of the cell cycle can be divided into three phases: 1-the gap 1 (G1) phase or growth 1 phase, 2-the S phase (DNA replication or DNA synthesis), and 3-the gap 2 (G2) phase or growth 2 phase. During the G1 phase, the cell synthesizes key enzymes which are required during DNA replication (S phase) and cell division (M phase). Cytoplasmic factors are proteins and messenger RNAs (mRNAs) that control cell functions during the cell cycle. This cycle is modulated by proteins known as control factors, i.e., cyclins and cyclin-dependent kinases (Cdks) that work together to control the progression through different phases of the cell cycle. The transition from S to G2 occurs after DNA replication. This transition (S to G2) is controlled by a DNA damage checkpoint orchestrated by the ATM (Ataxia telangiectasia mutated) and ATR (Ataxia Telangiectasia and Rad3 related) kinases which are recruited to DNA damage sites. Moreover, the ​transition from G2 to M phase is mediated by the accumulation of mitotic inducers, which lead to an increase in the activity of mitotic kinase and finally trigger mitotic entry.

7 0
3 years ago
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