INTEGRATED SCIENCES MYP 5: UNIT 1 - 3 HEREDITY , ENERGY, PHYSICS

Gamete

Sex cells that have half the usual number of chromosomes (haploid), allowing them to combine with another gamete to form a complete set (zygote).

Prophase I

First stage of meiosis where chromosomes condense, pair up, and crossing over occurs, exchanging DNA between homologous chromosomes.

Metaphase I

The stage where paired homologous chromosomes (tetrads) align in the middle of the cell, preparing for separation.

Anaphase I

The stage where homologous chromosomes (each with two chromatids) are pulled to opposite ends of the cell.

Telophase I

The stage where two new nuclei form around separated chromosomes, followed by cell division to form two cells.

Chromatid

One of two identical halves of a duplicated chromosome, connected by a centromere.

Crossing Over

The process in Prophase I where homologous chromosomes exchange sections of DNA, increasing genetic diversity.

Homologous Chromosomes

Chromosome pairs (one from each parent) that are similar in size, shape, and gene content. They pair up during meiosis I.

Haploid

A cell containing half the usual set of chromosomes (e.g., gametes: sperm and egg).

Diploid

A cell containing two copies of each chromosome (e.g., somatic cells).

Meiosis

The process of cell division where one cell divides into four genetically unique daughter cells, each with half the number of chromosomes (haploid). Meiosis is essential for sexual reproduction.

Gene Mutations

Changes in DNA sequences that can lead to different amino acids being translated, altering the structure and function of proteins.

Single Point Mutations

Changes caused by a deletion, addition, or substitution of a single base in DNA.

Germline Mutations

Mutations that occur in gametes (sperm or egg) and are hereditary, meaning they are passed to offspring during sexual reproduction.

Chromosome Mutations

Errors in the separation of chromosomes during meiosis I, leading to changes in the number or structure of chromosomes.

Asexual Reproduction

A single parent gives rise to clones, which are genetically identical to the parent.

Sexual Reproduction

Requires two parents and combines genetic material to produce genetically diverse offspring.

Genotype

The genetic makeup of an organism (e.g., homozygous dominant, heterozygous).

Phenotype

Observable physical traits resulting from a genotype (e.g., eye color, freckles).

Allele

Different forms of a gene that exist at a specific locus on a chromosome.

Chromosome

A structure made of protein and a single molecule of DNA that carries genetic information from cell to cell.

Diffusion (In Bio)

The movement of particles from an area of higher concentration to an area of lower concentration until equilibrium is reached.

Exothermic Reaction

Releases energy to the surroundings; temperature increases (e.g., combustion).

Endothermic Reaction

Absorbs energy from the surroundings; temperature decreases (e.g., photosynthesis).

Energy

The capacity to do work or transfer heat, existing in forms such as kinetic, potential, thermal, chemical, and electrical.

Heat

The transfer of thermal energy between systems or objects with different temperatures, flowing from hotter to cooler.

Bond Enthalpy

Energy change = Total energy of bonds broken (reactants) - Total energy of bonds formed (products).

Diffusion in chem:

Example with HCL and NH3

• Molecular motion

• guide through concentration gradients

• influence through particle mass

Enzyme

Biological catalyst that increases the rate of a reaction

Lipases

This group of enzymes help digest fats in the gut.

Amylase

In the saliva, helps change starches into sugars.

Maltase

Occurs in the saliva, and breaks the sugar maltose into glucose.

Trypsin

Beak proteins down into amino acids in the small intestine.

Lactase

breaks lactose, the sugar in milk, into glucose and galactose.

Acetylcholinesterase

These enzymes break down the neurotransmitter acetylcholine in nerves and muscles.

Helicase

Helicase enzymes unravel DNA.

DNA polymerase

These enzymes synthesize DNA from deoxyribonucleotides.

Wavelength

Distance between a point on one wave and the same point on the next wave, measured in meters.

Frequency

A number of waves produced by a source each second, common units of measurement:  Hertz (Hz)

Speed of a wave

The distance a wave can travel in a certain amount of time. The unit it is measured in is m/s

Formula

• v is the wave speed in metres per second, m/s

• f is the frequency in hertz, Hz

• λ (lamda) is the wavelength in metres, m

Crest

Labelled as the highest surface part of a wave

Trough

Labelled as the lowest surface part of a wave

Amplitude

A measurement of amount of energy transferred by the wave from its resting position and the highest position.

Refraction

the bending of a wave, like light, as it passes from one medium to another.

Factors affecting refraction

• the density of the mediums

• the angle of incidence.

Electromagnetic Spectrum

Continous spectrum of electromagnetic radiation

Types of wave

Radio waves, micro waves, infrared light, visible light, ultra violent light, x-rays, and gamma rays

Radio wave qualities

Property	Description
Wavelength	> 1 meter
Frequency	< 300 MHz
Speed	3 × 10⁸ m/s (in vacuum)
Energy	Very Low
Common Uses	Radio and TV broadcasting, communication systems, satellites
Dangers	Generally safe; prolonged exposure to strong fields may affect health

Microwaves qualities

Property	Description
Wavelength	1 meter – 1 millimeter
Frequency	300 MHz – 300 GHz
Speed	3 × 10⁸ m/s (in vacuum)
Energy	Low
Common Uses	Microwave ovens, mobile phones, radar systems
Dangers	Can cause tissue heating and internal burns if exposed at high intensity

Infrared light qualities

Property	Description
Wavelength	1 millimeter – 700 nanometers
Frequency	300 GHz – 430 THz
Speed	3 × 10⁸ m/s (in vacuum)
Energy	Moderate
Common Uses	Night vision, remote controls, heating lamps
Dangers	Prolonged exposure can cause skin burns and eye damage

Visible light qualities

Property	Description
Wavelength	700 nm (red) – 400 nm (violet)
Frequency	430 THz – 750 THz
Speed	3 × 10⁸ m/s (in vacuum)
Energy	Moderate
Common Uses	Enables human vision, lighting, photography
Dangers	Very bright or laser light can damage eyes

ultra violent light qualities

Property	Description
Wavelength	400 nm – 10 nm
Frequency	750 THz – 30 PHz
Speed	3 × 10⁸ m/s (in vacuum)
Energy	High
Common Uses	Sterilization, tanning beds, detecting counterfeit items
Dangers	Causes sunburn, skin aging, and increases skin cancer risk

X-ray qualities

Property	Description
Wavelength	10 nm – 0.01 nm
Frequency	30 PHz – 30 EHz
Speed	3 × 10⁸ m/s (in vacuum)
Energy	Very High
Common Uses	Medical imaging (e.g., broken bones), security scanners
Dangers	Can damage living tissue, increases cancer risk with overexposure

Gamma ray qualities:

Property	Description
Wavelength	< 0.01 nm
Frequency	> 30 EHz
Speed	3 × 10⁸ m/s (in vacuum)
Energy	Extremely High
Common Uses	Cancer radiotherapy, sterilizing medical tools, nuclear research
Dangers	Extremely hazardous; causes severe cellular and DNA damage

Snell’s Law

describes the relationship between the angles at which light enters and exits different materials

Snell’s Law formula

Snell's Law Formula: n₁sin(θ₁) = n₂sin(θ₂)

Snell Law Formula explanation

• n₁ = refractive index of the first medium

• n₂ = refractive index of the second medium

• θ₁ = angle of incidence

• θ₂ = angle of refraction

What is titration?

a technique where a solution of known concentration is used to determine the concentration of an unknown solution.

How to carry out titration

A titration is performed by slowly adding a titrant of known concentration to a reaction vessel containing a solution of unknown concentration, using a burette. The end point is detected using a suitable indicator that changes color when the reaction is complete.