Kanchipuram

Nishant Raj replied | 23 hrs ago

The cell cycle is the process by which a cell grows, prepares for division, and divides into two daughter cells. It is divided into two main phases:

🌿 1. Interphase (Preparation Phase)

This is the longest phase of the cell cycle and is further divided into 3 sub-phases:

➤ G₁ Phase (Gap 1):

• The cell grows in size.

• Proteins and organelles are synthesized.

• The cell performs its regular functions.

• It prepares for DNA replication.

• Checkpoint: The cell checks if it's ready to copy DNA.

➤ S Phase (Synthesis Phase):

• DNA replication occurs here.

• Each chromosome is copied, forming sister chromatids.

• Now the cell has double the amount of DNA, but the number of chromosomes remains the same.

➤ G₂ Phase (Gap 2):

• The cell continues to grow.

• It synthesizes proteins needed for mitosis (like spindle fibers).

• The cell checks for DNA damage and repairs it.

• Prepares for actual cell division.

🌱 2. M Phase (Mitotic Phase)

This phase includes mitosis (division of the nucleus) and cytokinesis (division of the cytoplasm). Mitosis is divided into 4 stages:

➤ Prophase:

• Chromosomes condense and become visible.

• Each chromosome consists of 2 sister chromatids.

• The nuclear membrane starts to break down.

• The spindle fibers begin to form from centrosomes.

➤ Metaphase:

• Chromosomes line up at the center (equator) of the cell.

• The spindle fibers attach to the centromere of each chromosome.

➤ Anaphase:

• The centromere splits.

• Sister chromatids are pulled apart toward opposite poles of the cell by spindle fibers.

• Now, each chromatid is an individual chromosome.

➤ Telophase:

• Chromosomes reach the poles and de-condense (become thread-like again).

• Nuclear envelopes re-form around each set of chromosomes.

• The cell has two nuclei now.

🌊 Cytokinesis (Not part of mitosis, but happens at the end):

• The cytoplasm divides.

• Two daughter cells are formed, each with the same number of chromosomes as the parent cell.

Kanika Rawat replied | 2 hrs ago

• Interphase: G₁ (growth), S (DNA copy), G₂ (preparation)
• Mitosis: Prophase, Metaphase, Anaphase, Telophase → leads to two identical cells.

Nishant Raj replied | 23 hrs ago

The valency of carbon is 4.
This means carbon can form four covalent bonds with other atoms to complete its outer shell (which needs 8 electrons, but carbon has only 4 in its outer shell).

🔗 Property of Carbon that Leads to Long Chain Compounds:

This property is called Catenation.

✨ Catenation:

• It is the ability of carbon atoms to form long chains or rings by bonding with other carbon atoms.

• These chains can be straight, branched, or cyclic.

• Carbon can also bond with other elements like hydrogen, oxygen, nitrogen, etc., to form a vast variety of compounds.

🧪 Why is Carbon So Good at Catenation?

1. Small size → Strong C–C bonds.

2. Tetravalency → Can form 4 stable bonds.

3. Stable covalent bonding with many elements.

Kanika Rawat replied | 2 hrs ago

Carbon has a valency of 4, so it forms four covalent bonds with other atoms.

It can bond with carbon atoms as well as other elements like hydrogen, oxygen, etc.The property of catenation allows carbon to form long chains and rings.These chains can be straight, branched, or cyclic.This is why carbon forms a large number of compounds called organic compounds.

Kaizen Global replied | 17 Jun

ChatGPT said: