IGCSE Biology 2024 Top 10 Most Important Definitions

Summary

This video presents the top 10 essential definitions in IGCSE Biology, covering key concepts like double circulation, active transport, and the definition of a species. It explains how hormones function, the significance of homeostasis in maintaining internal balance, and the characteristics of a population. The transcript also clarifies important terms such as genes, chromosomes, and excretion, emphasizing their roles in biological processes. This concise overview serves as a valuable resource for students preparing for their IGCSE examinations, highlighting fundamental topics necessary for a solid understanding of biology.

Takeaways

• 😀 Double circulation refers to blood passing through the heart twice to complete a full cycle around the body.
• 🚀 Active transport is the movement of ions or large molecules across the cell membrane using carrier proteins, requiring energy from respiration.
• 🐾 A species is defined as a group of organisms that can reproduce to produce fertile offspring.
• 🧬 A gene is a segment of DNA that encodes for a specific protein, while an allele is a different form of a gene.
• 🧪 A chromosome consists of a length of DNA that contains multiple genes.
• 💉 Hormones are chemicals secreted by endocrine glands, transported by blood, that alter the activity of specific target organs.
• 🌡️ Homeostasis is the process of maintaining a constant internal environment within an organism.
• 👥 A population is a group of organisms of the same species residing in the same habitat at the same time.
• 🚮 Excretion is the removal of toxic substances, waste products of metabolism, and excess substances from the body.

Q & A

What is double circulation?

Double circulation is when the blood goes through the heart twice to complete a full cycle around the body.

What is active transport?

Active transport is the movement of ions or large molecules through the cell membrane using carrier proteins against concentration gradients, utilizing energy from respiration.

How is a species defined in biology?

A species is defined as a group of organisms that reproduce to produce fertile offspring.

What is a gene?

A gene is a length of DNA that codes for a protein.

What is an allele?

An allele is a different form of a gene.

What does a chromosome contain?

A chromosome is a length of DNA that contains genes.

What is the role of hormones in the body?

Hormones are chemicals secreted by endocrine glands, carried by the blood, that alter the activity of specific target organs.

What is homeostasis?

Homeostasis is the process of maintaining a constant internal environment in the body.

What defines a population in biological terms?

A population is a group of organisms of the same species living in the same habitat at the same time.

What is excretion?

Excretion is the removal from the body of toxic substances, waste products of metabolism, and substances in excess of requirements.