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3 years ago

True / Fasle

Biology

1 answer:

nydimaria [60]3 years ago

4 0

Answer: True, both of the given statements are true.

Explanation:

1. Nearly all the environment contains microorganism whether it is soil, air, water or any other surface. They have the ability of live in the extreme conditions.

There are different forms of bacteria found at different places. Some of them are thermophiles that at found in extremely hot conditions such as thermal vents.

The organism like Psychrophiles are the microorganisms that have the ability to survive at lower temperatures. Example: bacteria found in polar regions.

2. A culture can be defined as a pure culture if it has an unadulterated species of bacteria. It has no contamination and if a small inoculum from the pure sample is streaked on a plate then a pure culture of the sample is obtained.

This should be done in an aseptic condition so that the bacterial species should be free from contamination.

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Answer:

D.) Stimulus is the correct answer.

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3 years ago

The difference between prokaryotic and eukaryotic gene regulation

sleet_krkn [62]

Answer:

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Explanation:

To understand how gene expression is regulated, we must first understand how a gene codes for a functional protein in a cell. The process occurs in both prokaryotic and eukaryotic cells, just in slightly different manners.

Prokaryotic organisms are single-celled organisms that lack a cell nucleus, and their DNA therefore floats freely in the cell cytoplasm. To synthesize a protein, the processes of transcription and translation occur almost simultaneously. When the resulting protein is no longer needed, transcription stops. As a result, the primary method to control what type of protein and how much of each protein is expressed in a prokaryotic cell is the regulation of DNA transcription. All of the subsequent steps occur automatically. When more protein is required, more transcription occurs. Therefore, in prokaryotic cells, the control of gene expression is mostly at the transcriptional level.

Eukaryotic cells, in contrast, have intracellular organelles that add to their complexity. In eukaryotic cells, the DNA is contained inside the cell’s nucleus and there it is transcribed into RNA. The newly synthesized RNA is then transported out of the nucleus into the cytoplasm, where ribosomes translate the RNA into protein. The processes of transcription and translation are physically separated by the nuclear membrane; transcription occurs only within the nucleus, and translation occurs only outside the nucleus in the cytoplasm. The regulation of gene expression can occur at all stages of the process (Figure 1). Regulation may occur when the DNA is uncoiled and loosened from nucleosomes to bind transcription factors (epigenetic level), when the RNA is transcribed (transcriptional level), when the RNA is processed and exported to the cytoplasm after it is transcribed (post-transcriptional level), when the RNA is translated into protein (translational level), or after the protein has been made (post-translational level).

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3 years ago

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Difference male and female reproductive system anatomy

belka [17]

Men have testicles, and a scrotum. Women have ovaries, uterus and a vagina. Also women have wider pelvises than men so that they can have children.

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3 years ago

How did Kepler develop his second law of motion?(1 point)

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Answer:

He found that the planets do not all move at the same speed. (A)

Explanation:

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I’ll mark brainliest <br> explain the sequence of events in the replication of DNA

salantis [7]

Explanation:

Replication is the process by which a double-stranded DNA molecule is copied to produce two identical DNA molecules. DNA replication is one of the most basic processes that occurs within a cell. Each time a cell divides, the two resulting daughter cells must contain exactly the same genetic information, or DNA, as the parent cell. To accomplish this, each strand of existing DNA acts as a template for replication.

How is DNA replicated?:

Replication occurs in three major steps: the opening of the double helix and separation of the DNA strands, the priming of the template strand, and the assembly of the new DNA segment. During separation, the two strands of the DNA double helix uncoil at a specific location called the origin. Several enzymes and proteins then work together to prepare, or prime, the strands for duplication. Finally, a special enzyme called DNA polymerase organizes the assembly of the new DNA strands. The following description of this three-stage process applies generally to all cells, but specific variations within the process may occur depending on organism and cell type.

What triggers replication?

A schematic shows a double-stranded DNA molecule undergoing the replication process. The left side of the molecule is double-stranded. In the middle of the molecule, a globular yellow structure, representing the protein helicase, is bound to the ends of several nitrogenous bases on the lower strand. To the right of the helicase protein, the double helix has opened and the top strand has separated from the bottom. At right, a short segment of the newly replicated double-stranded DNA molecule is visible.

Helicase (yellow) unwinds the double helix.

The initiation of DNA replication occurs in two steps. First, a so-called initiator protein unwinds a short stretch of the DNA double helix. Then, a protein known as helicase attaches to and breaks apart the hydrogen bonds between the bases on the DNA strands, thereby pulling apart the two strands. As the helicase moves along the DNA molecule, it continues breaking these hydrogen bonds and separating the two polynucleotide chains.

A schematic shows a double-stranded DNA molecule undergoing the replication process. At right, the double helix has opened and the top strand has separated from the bottom. A globular yellow structure, representing the protein helicase, is bound to the ends of several nitrogenous bases on the lower strand. A red globular molecule, representing the enzyme primase, is bound to the lower DNA strand to the right of helicase.

While helicase and the initiator protein (not shown) separate the two polynucleotide chains, primase (red) assembles a primer. This primer permits the next step in the replication process.

Meanwhile, as the helicase separates the strands, another enzyme called primase briefly attaches to each strand and assembles a foundation at which replication can begin. This foundation is a short stretch of nucleotides called a prime

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