Water
What type of bond holds the hydrogen and oxygen atoms together within a single water molecule?
Covalent bonds
What is the first step of the scientific method, where you notice something in the natural world?
Make an observation
What molecule contains the genetic information that directs structure and function in living things?
DNA
Why do some atoms become more chemically stable once they have formed covalent bonds?
Atoms become more stable because sharing electrons in covalent bonds allows them to fill their outermost (valence) shell. A full valence shell lowers potential energy and makes the atom less reactive—similar to the stability of noble gases.
What type of bond forms between water molecules and gives water many of its unique properties?
Hydrogen bonds
What is a hypothesis in science?
A testable, falsifiable explanation for an observation.
What is the term for maintaining stable internal conditions, like body temperature or blood pH, despite outside changes?
Homestasis
What is the difference between a covalent bond and an ionic bond?
A covalent bond is a sharing of electrons, while an ionic bond is a transfer of electron(s)
Why does water have a high specific heat compared to many other substances?
Hydrogen bonds absorb heat energy, resisting temperature changes. (hard to break)
Why is it important to include a control group in an experiment?
It allows comparison by showing the effect of the variable being tested.
How does natural selection drive populations of organisms to change from one generation to the next?
Individuals with advantageous traits survive and reproduce more, passing those traits on, which leads to adaptation and evolutionary change over time.
What property of water molecules allows them to form Hydrogen bonds with each other
The polarity of the molecule. Oxygen attracts the electrons, making the oxygen slightly negative and the hydrogen slightly positive, forming a lattice structure.
WHy does water stick together to form droplets on the surface of objects
The hydrogen bonds are attracted to each other, creating cohesion (water sticking to water)
Why is repeatability (replication) essential in scientific experiments?
It ensures that results are reliable, not due to chance, and can be confirmed by other scientists.
What are emergent properties and give one example
New characteristics that appear at higher levels of biological organization; for example, consciousness emerging from networks of neurons.
Why do nonpolar molecules not dissolve in water
Ex. Water and oil
Nonpolar molecules, like oils, do not dissolve well in water because they lack charged or polar regions, so they cannot form hydrogen bonds with water. Instead, water molecules stick to each other, pushing nonpolar molecules aside.
Why does sweating cool the body
Water absorbs heat as it evaporates, breaking hydrogen bonds and carrying heat away from the skin.
Why is it important to test only one independent variable at a time in an experiment?
To ensure that any observed effect can be directly linked to that variable, avoiding confusion from multiple changing factors.
Give the process from DNA to proteins
DNA is transcribed into messenger RNA (mRNA), which is then translated by ribosomes into a chain of amino acids that fold into a functional protein.
In terms of bonding, why does ice float
hydrogen bonds in ice form a stable lattice that spaces water molecules farther apart, making ice less dense than liquid water.