Biology, 28.10.2020 16:10, heyitzmeamelie

PP HELP Describe the major events in the cell cycle. Begin at G1 and follow around the cycle through M

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answered: mia7955

Answer/Explanation:

The cell cycle consists of interphase and mitosis (M). Within interphase, there are three phases: G1, S, and G2.

G1 phase - the first 'gap' phase.The cell grows in size, and synthesises the necessary mRNA and proteins required to divide. This is also where the key decision as to whether the cell will divide takes place. This is based on whether or not the environmental conditions are favourable for division and whether the cell is receiving the correct signals to divide. This is called the G1/S transition, and is the critical decision making point as to whether the cell cycle will progress.

S phase - the 'synthesis' phase. The cell replicates its DNA in preparation for passing the genetic material onto the daughter cells. Once the cell's DNA is replicated, it enters G2.

G2 phase - the second 'gap' phase. The cell continues to grow in size and prepare for mitosis. There is a DNA damage checkpoint here, where the cell ensures that the DNA has properly replicated. Next, it moves into mitosis (M).

M phase - the mitosis phase. This consists of 4 stages (PMAT) - prophase, metaphase, anaphase, telophase. The cytoplasm divides during cytokinesis

During prophase the chromosomes condense and pair up. The mitotic spindle forms, and the nuclear membrane disappears. During metaphase, the chromosomes line up at the centre of the cell - at the metaphase plate. The mitotic spindles attach to the chromosomes - to each sister chromatid.During anaphase, the sister chromatids are pulled apart to opposite poles of the cellDuring telophase, two new nuclei form, surrounding the two new sets of chromosomes. Cytokinesis then occurs, pinching the membrane to create two new cells.

answered: Guest

1. amino acid refers to the fundamental building block of proteins, comprising of an amino group and a carboxyl group.

2. catalyst refers to any substance, which increases the rate of chemical reaction without being used up in the reaction.

3. a complex molecule containing he genetic code is dna or deoxyribonucleic acid.

4. an enzyme refers to a molecule of protein, which is unique in accelerating up a particular chemical reaction in the biological systems.

5. nucleic acid refers to an sequence of sugars, phosphates, and nitrogenous bases, for example, dna and rna.

6. a protein refers to a large, composite organic molecule comprising of a huge number of amino acids associated together with the of peptide bonds.

7. rna refers to a nucleic acid that takes part in the production of proteins.

8. substrate refers to a compound, which takes part in a chemical reaction, and is chemically modified by the reaction.

answered: Guest

answer;

-vessels in the chest

the diagnosis of angina pectoris literally means "vessels in the chest"

explanation;

-angina pectoris is the medical term for chest pain or discomfort due to coronary heart disease.it is the chest pain due to an inadequate supply of oxygen to the heart muscle. the pain is typically severe and crushing, and it is characterized by a feeling of pressure and suffocation just behind the breastbone.

agina pectoris is caused by reduced blood flow to your heart muscle. the blood carries oxygen, which the heart muscle needs to survive. when the heart muscle isn't getting enough oxygen, it causes a condition called ischemia