GRADE 9 -REVIEWER

REVIEW.....
the Wonders of Science

Respiratory System

The respiratory system is responsible for the exchange of oxygen and carbon dioxide in the body. It includes organs such as the lungs, bronchioles, and alveoli. The process of respiration involves inhalation and exhalation, as well as the diffusion of gases to and from body cells. The respiratory system also has protective mechanisms, such as the epiglottis and cilia, to prevent foreign substances from entering the airways.

Multiple Choice

What is the main function of the respiratory system?

• To exchange oxygen and carbon dioxide in the body

• To protect the airways from foreign substances

• To facilitate the diffusion of gases to and from body cells

• To regulate the process of inhalation and exhalation

Respiratory System:

To exchange oxygen and carbon dioxide in the body. It also helps facilitate the diffusion of gases to and from body cells. The respiratory system is responsible for regulating the process of inhalation and exhalation. Additionally, it helps protect the airways from foreign substances.

Remember this.......

• Cellular respiration: The process by which chemical energy in food molecules is released and captured in the form of ATP.

• Respiratory system: Includes the diaphragm, lungs, trachea, and nasal cavity.

• Breathing: The physical process of getting air in and out of the lungs.

• Respiratory rate: The average respiratory rate for a 6-year-old child is 20-30 breaths per minute.

• Circulatory system: Consists of arteries, veins, and blood vessels.

• Genes: Segments of DNA that contain instructions for making proteins.

• DNA: Base pairs in DNA are A-T and C-G, connected by covalent bonds.

Multiple Choice

Which process involves the release and capture of chemical energy in food molecules?

• Cellular respiration

• Respiratory system

• Breathing

• Circulatory system

Cellular Respiration

Trivia: Cellular respiration is the process by which cells break down food molecules to release chemical energy. It occurs in the mitochondria of cells and is essential for the survival of all living organisms. Without cellular respiration, organisms would not be able to generate the energy needed to carry out their daily activities. Fun Fact: The overall equation for cellular respiration is C6H12O6 + 6O2 → 6CO2 + 6H2O + ATP, where ATP represents the energy currency of the cell.

Remember this....

• A gene is a region in DNA that controls a hereditary characteristic

• A nucleotide consists of a nitrogen base, sugar, and phosphate

• The complimentary strand of A-A-G-C-C-A is T-T-C-G-G-T

• Francis Crick's partner in determining the structure of DNA is James Watson

Remember this....

• • Humans have 46 chromosomes

  • Chromosomes contain genetic information for development and function

  • Genes are responsible for inheriting specific characteristics

  • Genotype consists of structures called factors or genes

  • Sex chromosomes determine the sex of an organism

  • Sex-linked genes and traits are inherited through sex chromosomes

  • Genes found on sex chromosomes are called sex-linked genes

  • Species can become extinct due to environmental forces or evolutionary changes

Multiple Choice

Which scientist was Francis Crick's partner in determining the structure of DNA?

• James Watson

• Albert Einstein

• Marie Curie

• Isaac Newton

James Watson

Trivia: James Watson was Francis Crick's partner in determining the structure of DNA. Their groundbreaking discovery revolutionized the field of genetics and earned them the Nobel Prize in Physiology or Medicine in 1962. Their work laid the foundation for modern molecular biology and our understanding of genetic inheritance.

Remember this........

• Execution: The process of carrying out a plan or action.
• Exemption: Being freed from a rule or obligation.
• Consumption: The act of using up resources or goods.
• Destruction: The act of causing severe damage or harm.
• Sex-linked traits: Traits that are determined by genes located on the sex chromosomes.
• Sex-limited traits: Traits that are expressed in only one sex.

Multiple Choice

What are sex-linked traits?

• The process of carrying out a plan or action

• Being freed from a rule or obligation

• The act of using up resources or goods

• Traits that are determined by genes located on the sex chromosomes

Sex-Linked Traits

Traits that are determined by genes located on the sex chromosomes. These traits are typically more common in one gender than the other. Examples include color blindness and hemophilia. They are inherited differently than traits determined by genes on autosomes.