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3 years ago

6

Biology

1 answer:

Lelechka [254]3 years ago

6 0

Answer:

The cell membrane is selectively permeable, which controls the movement of materials in and out of the cell by passive and active transport.

Explanation:

According to this question, animal cells are made up of the following contents: 90% water and 10% protein, carbohydrates, nucleic acid, lipids and other molecules. The cell regulates this internal composition in a stable way via a process called HOMEOSTASIS.

The animal cell is able to regulate or maintain a stable internal composition by the possession of a selective permeable membrane called CELL MEMBRANE. The cell membrane is semi-permeable in the sense that it allows the entry of some molecules into and out of the cell and blocks others.

Some molecules are allowed by the cell membrane without the need for energy input in a transport called PASSIVE TRANSPORT while some requires energy input in a transport called ACTIVE TRANSPORT.

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What is base ? what is acid and salts? plz explantion this question

Dvinal [7]

Explanation:

In acid – base chemistry, salts are ionic compounds that result from the neutralization reaction of an acid and a base. Basic salts contain the conjugate base of a weak acid, so when they dissolve in water, they react with water to yield a solution with pH greater than 7.0.

8 0

3 years ago

Read 2 more answers

Gravity is the force of ______ between all objects.

Rudiy27

Answer:

Gravity is a force of attraction that exists between any two masses, any two bodies, any two particles. Gravity is not just the attraction between objects and the Earth. It is an attraction that exists between all objects, everywhere in the universe.

or just mass.

The Law of Universal Gravitation states that the force of gravity acts between all objects in the universe that have mass.

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3 years ago

Of the answers below, what is the smallest nucleotide sequence that could code for a protein with 300 amino acids?

ololo11 [35]

The nucleotide sequence would have to have 900 nucleotides in order to code for a protein of 300 amino acids. When translating RNA into proteins, RNA is read 3 bases at a time. Each group of 3 bases is a codon, and each codon codes for an amino acid. When read, the proper amino acid is added to a growing chain of amino acids, which will be folded to become a protein.

Therefore, 300 amino acids * 3 nucleotides per amino acid = 900 nucleotides.

6 0

3 years ago

Place the events in the correct order:

Alecsey [184]

Answer:

1. Chromatin condense into chromosomes.

4. Homologous chromosomes pair up (formation of tetrads).

5. Homologous chromosomes separate and move to poles.

2. Sister chromatids separate.

3. Chromosomes unravel in to chromatin.

Explanation:

This question portrays the process of meiosis in a cell. The ordered sequence of events in the options are:

1. Chromatin condense into chromosomes - This process occurs in the Prophase stage. Prior to the cell division, the nuclear material is found as Chromatin material. This Chromatin material then undergoes condensation to form visible chromosomes.

4. Homologous chromosomes pair up (formation of tetrads) - This process also occurs during the Prophase stage of meiosis I. In this stage, homologous chromosomes (similar but non-identical chromosomes received from each parent) are paired up side by side to form a structure known as TETRAD or BIVALENT.

5. Homologous chromosomes separate and move to poles - This process characterizes the Anaphase stage of meiosis I. Homologous chromosomes are pulled apart to opposite poles of the cell by spindle microtubules.

2. Sister chromatids separate - After meiosis I, meiosis II involving sister chromatids instead of homologous chromosomes follows. In the Anaphase stage of meiosis II specifically, sister chromatids are pulled apart towards opposite poles of the cell.

3. Chromosomes unravel in to chromatin - After the whole division process i.e. karyokinesis (division of the nuclear material), the chromosomes begin to unravel to form the CHROMATIN threads once again. This process occurs in the Telophase stage of meiosis.

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3 years ago

How was bacteria first discovered?

matrenka [14]

Bacteria were first observed by the Dutch microscopist Antonie van Leeuwenhoek in 1676

<u>-TheUnknownScientist</u>

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3 years ago