Study Questions #1

Question 1

What characteristics do all living things on earth have in common?

Answer 1

Cellular organization, metabolism, reproduction, heredity, and evolution, sensitivity, regulation, homeostasis, common origin.

Question 2

In the year 2030 you are assigned to look for life on Jupiter’s moon Europa. What will you look for and how will you decide if its alive?

Answer 2

Cellular organization, metabolism, reproduction, heredity, and evolution, sensitivity, regulation, homeostasis, common origin.

Question 3

What is the difference between a hypothesis and a theory?

Answer 3

Hypothesis is an educated answer proposed in a scientific investigation- tested by experiments, must be falsififiable.

Theory is a hypothesis that has been repeatedly tested over time and supported by experimental data. Ie theory of evolution by natural selection.

Question 4

The 5 steps to designing an experiment.

Answer 4

Make a falsifiable hypothesis
Make predictions
Experiment- results/interpretation
Controls - part of experiment where variable is not tested

Data used to support of fail to support hypothesis

Question 5

Who was the first to propose evolution explains the fossil record?

Answer 5

LAMARCK

Theory of evolution acquired characteristics
First to say “evolution” against the church “creationists”

Question 6

How did Lamarck propose that evolution occurs?

Answer 6

• organisms evolve as they strive for perfection

- acquired changes are passed to offspring

Question 7

What contribution did Lyell make to Darwin’s theory of evolution?

Answer 7

Slow pace of teleological processes. Earth is old. Lyell studied geology/rocks/fossils.
Decomposition of soil, fossil evidence

Question 8

What contribution did Malthus make to Darwin’s theory of evolution?

Answer 8

Populations grow in size exponentially-food supply is limited, nature controls population size through death.

Question 9

What evidence led Darwin to propose his theory?

Answer 9

observations on trip 
Lyell's geology/fossils 
Malthus principles of population 
Extinct species related to living organisms 
Characteristics of species vary

Question 10

What are the two parts to Darwin’s theory?

Answer 10

a) variability in a population, some more fit than others

b) genes transferred to next generation (heredity)

Question 11

What are the 5 key assumptions to Darwin’s theory?

Answer 11

Organisms produce more offspring then will survive and reproduce.
Variation among individuals
Surviving organisms are superior (fit/adapted) in certain characteristics.
Characteristics are heritable lots of time on earth passed for these changes.

Question 12

Why is heredity a key element in Darwin’s theory of evolution by natural selection?

Answer 12

Heredity is the key element because it provides the mechanism of evolution.

Question 13

Why is evolution the main unifying theme of biology?

Answer 13

It explains how life came about.

Question 14

Why is Darwin’s theory of evolution a key turning point in biology?

Answer 14

Biology became investigatory, not “stamp collecting” (pure observation)
Evolution became the unifying theme of biology

Question 15

Why do biologists need to know a lot of chemistry?

Answer 15

• life is made of chemicals
• life converts nutrients into bio-chemicals by chemical reactions
• life is chemistry with a purpose
• to understand life, must understand chemistry

Question 16

What is an atom and what are they made of?

Answer 16

An atom is the smallest unit of matter with unique chemical properties. They are made of protons neutrons and electrons.

Question 17

What is an element?

Answer 17

An element is a chemical with the same atomic number

Question 18

What is the difference between atomic mass and atomic number?

Answer 18

Atomic number is the number of protons.

Atomic mass is the number of protons and neutrons.

Question 19

Why is atomic number important?

Answer 19

Atomic number determines number of electrons, therefore the chemical and physical properties of an element.
Reactivity of an element is determined by the number of electrons in the valence shell.

Question 20

What are isotopes?

Answer 20

Isotopes are different forms of the same element with the same atomic number but different atomic mass due to different numbers of neurons.

Question 21

What is radioactive decay, and why is it useful?

Answer 21

Radioactive decay is the emission of particles from unstable isotopes; involves the release of energy; nucleus decays. used in dating and medicine

Question 22

What is the difference between a cation and anion?

Answer 22

Cations have a positive charge (more protons than electrons)

Anions have a negative charge (more electrons than protons)

Question 23

What is the difference between oxidation and reduction?

Answer 23

Oxidation loses electrons and reduction gains electrons. LEO - loss, electrons, oxidation GER- gain, electron, reduction

Question 24

Why are redox reactions important to living organisms?

Answer 24

When electrons move they take their energy with them. Transfer of energy.

Question 25

Difference between an orbital and an energy level?

Answer 25

An orbital is the probable location of an electron and can only contain 2 electrons but an energy level contains several orbitals and can hold 8 electrons.

Question 26

Valence shell

Answer 26

The valence shell is the last energy level of an element that can lose or gain electrons. It determines how elements react with each other.

Question 27

Why do valence electrons determine the chemical properties of an element?

Answer 27

They determine the chemical properties because it determines how the element reacts with other elements. want to fill shell.

Question 28

Why do elements whose atomic numbers differ by 8 have similar properties?

Answer 28

They have similar properties because they form similar bonds with other elements. same number of electrons in valence shell.

Question 29

Why is helium chemically inert?

Answer 29

Helium is chemically inert because its valence shell is filled.

Question 30

Why bromine is reactive?

Answer 30

Bromine is very reactive because it only needs one electron to fill its valence shell

Question 31

Difference between ionic and covalent chemical bond?

Answer 31

Ionic- give/take electrons; weaker bond covalent- share electrons; stronger bond

Question 32

What sort of bonds do you expect lithium to make?

Answer 32

I’d expect lithium(#3) to form ionic bonds because it has a charge of +1 only needs to lose 1 electron. (1or2+ charge - ionic, 1 or 2- charge- ionic)

Question 33

What sort of Bonds do you expect phosphorus to make?

Answer 33

Phosphorus often forms covalent bonds. charge of -3. Will share electrons to fill shell. (if valence shell is half filled- covalent)

Question 34

Why are weak bonds important?

Answer 34

Weak bonds are important for reactions where bonds are often broken and formed. It takes less energy to break them. An example is DNA unzipping and zipping.

Question 35

What sorts of weak bonds are common?

Answer 35

Ionic bonds in water, hydrogen bond, van der Waals, and hydrophobic interactions

Question 36

Hydrogen bond

Answer 36

A hydrogen bond is due to polarity. molecules have a partial positive and negative because some atoms attract electrons more than others.

Question 37

Van der Waals

Answer 37

Van der Waals are due to transient(don’t last) polarity of electrically neutral molecules, sometimes electron distribution is uneven, atoms with partial charge attract atoms with opp charge, induce uneven distribution in neighbors, have optimal Distance, important for protein and dna structure.

Question 38

4 factors that influence rate of chemical reactions

Answer 38

[reactants]
[products]
Temperature
Catalysts

Question 39

Most abundant elements

Answer 39

SPONCH- Sulfur, Phosphorus, Oxygen, Nitrogen, Carbon, Hydrogen

Question 40

Why are SPONCH most abundant

Answer 40

They form useful molecules

Question 41

Difference between macronutrient and micronutrient

Answer 41

The difference is how much organisms require them. Macronutrients are needed more than micronutrients.

Question 42

Difference between organic and inorganic molecule

Answer 42

Organic molecule- any molecule that contains reduced C

Inorganic molecules- everything else

Question 43

Fundamental reason for all the properties of water

Answer 43

The fundamental reason is that water is polar and hydrogen bonds

Question 44

Difference between adhesion and cohesion

Answer 44

Cohesion= water to water bonds
Adhesion= water to anything else bonds

Question 45

Why does water have a high specific heat and heat of vaporization

Answer 45

It has a high specific heat and heat of vaporization because it forms lots of hydrogen bonds and you have to break the hydrogen bonds to heat it and make them to release it.

Question 46

Why should you use deodorants and not antiperspirants?

Answer 46

sweating decreases body temperature and is necessary

Question 47

Why does ice float?

Answer 47

Ice floats because water has a lower density at lower temperatures(after 4degrees C)

Question 48

Why is water a good solvent?

Answer 48

Water is a good solvent because it is polar.

Question 49

Why are ionic bonds weaker in water?

Answer 49

Water separates ions, water forms hydration shell around ions

Question 50

Difference between mean and median?

Answer 50

Mean is the average and median is the middle number of data.

Question 51

Why is median used more than mean

Answer 51

Better measure of central tendency(median should be the top of the bell curve).

Question 52

What is standard deviation and how is it different from variance?

Answer 52

SD is the square root of the variance, denotes degree to which each value deviates from the mean

Question 53

What is a statistical test and what is it used for?

Answer 53

Tests a hypothesis, observed data is compared to expected data in order to analyze the data.