Biology Test 1

isotope

isotope

one or more forms of an element that have the same number of neutrons

are all isotopes radioactive?

No, some are stable

what is a radioactive isotope?

an isotope that spontaneously emits particles or energy to form a more stable element.

what is the atomic number or iron?

26

what is the mass number for iron?

56

what is the number of protons for iron?

26 protons

what is the number of neutrons for iron?

30 neutrons

what is the number of electrons for iron?

26 electrons

how many shells would iron have?

4 shells

what goes inside the Bohr model “shell” at the core?

the number of protons and neutrons

how many circles do you draw in total around the shell?

however many protons/electrons you have

what is a covalent bond?

the strongest bond

• shares electrons with another molecule

• the extra bonds you add to complete a “shell” in the Bohr model diagram

what is an ionic bond?

a strong bond

• gives electrons for other molecules

what is a hydrogen bond?

weaker bond

• between one slightly positive atom and one slightly negatively changed element

• does NOT have to have hydrogen

smallest unit of life?

cell

smallest unit of matter?

atom

macromolecule

a bunch of molecules combined

what is the scientific method (step by step)?

make an observation>ask a question>make a prediction>make a hypothesis>test the hypothesis>analyze the result (is it supported or not)>form the conclusion and report

a hypothesis MUST BE _____________.

falsifiable

independent variable

what “I” change

dependent variable

what is measured

the dependent variable depends on the ______________________________.

independent variable

Which of the following statements is false?
Organelles exist within cells which exist within tissues.

• Tissues exist within organs which exist within organ systems.

• Communities exist within populations which exist within ecosystems.

• Communities exist within ecosystems which exist in the biosphere.

Communities exist within populations which exist within ecosystems.

Which of the following sequences represents the hierarchy of biological organization from the most complex to the least complex level?
organ, organism, tissue, organelle, molecule

• organism, community, biosphere, molecule, tissue, organ

• biosphere, ecosystem, community, population, organism

• organelle, tissue, biosphere, ecosystem, population

biosphere, ecosystem, community, population, organism

A suggested and testable explanation for an event is called a _________________________.

hypothesis

The type of logical thinking that uses related observations to arrive at a general conclusion is called _____________________________.

inductive reasoning

inductive reasoning is

a form of logical thinking that uses related observations to arrive at a general conclusion

deductive reasoning is

a form of logical thinking that uses a general statement to predict specific results

the scientific method is

research with defined steps that include experiments and careful observation

hypothesis-based science

begins with a specific explanation that is then tested

How many neutrons do (K) potassium-39 and potassium-40 have, respectively?

39 = 20 neutrons

40 = 21 neutrons

Magnesium has an atomic number of 12. How many neutrons, electrons, and protons does magnesium have?

neutrons = 12

protons = 12

electrons = 12

hydrogen bond

Which type of bond represents a weak chemical bond?

An isotope of sodium (Na) has a mass number of 22. How many neutrons does it have?

12 neutrons

Which of the following statements is not true?

• Water is polar.

• Water stabilizes temperature.

• Water is essential for life.

• Water is the most abundant atom in Earth’s atmosphere.

Water is the most abundant atom in Earth’s atmosphere.

Using a pH meter, you find the pH of an unknown solution to be 8.0. How would you describe this solution?

• weakly acidic

• strongly acidic

• weakly basic

• strongly basic

weakly basic

Cellulose and starch are examples of:

• monosaccharides

• disaccharides

• lipids

• polysaccharides

polysaccharides

Phospholipids are important components of:

• the plasma membrane of animal cells

• the ring structure of steroids

• the waxy covering on leaves

• the double bond in hydrocarbon chains

the plasma membrane of animal cells

polar covalent bond

electrons are pulled toward one atom and away from another, resulting in slightly positive and slightly negative charged regions of the molecule

nonpolar bond

forms between atoms when electrons are shared equally between atoms, resulting in no regions with partial charges as in polar covalent bonds

The monomers that make up proteins are called

• nucleotides

• disaccharides

• amino acids

• chaperones

amino acids

Explain why water is an excellent solvent.

Water molecules are polar, meaning they have separated partial positive and negative charges. Because of the charges, water molecules are able to surround charged particles created when a substance dissociates.

Explain at least three functions that lipids serve in plants and/or animals.

Fat serves as a valuable way for animals to store energy. It can also provide insulation. Phospholipids and steroids are important components of cell membranes.

Explain what happens if even one amino acid is substituted for another in a polypeptide chain. Provide a specific example.

a change in gene sequence can lead to a different amino being added to a polypeptide chain instead of the normal one. This causes a chain in protein structure and function. For example, in sickle cell anemia, the hemoglobin B chain has a single amino acid substitution. Because of this change, teh disc-shaped red blood cells assume a crescent shape, which can result in serious help problems.

What are the levels of organization?

atom - molecule - organelles - cells - tissue - organs and organ systems - organisms, populations, and communities - ecosystem - biosphere

What are the building blocks of molecules?

atoms

What allows an item to float on top of water

The surface tension of the item

What are the monomers that make up proteins?

• Sugars 

• Hormones 

• Amino acids 

• Nucleotides

amino acids

denaturation is

the loss of shape in a protein as a result of changes in temperature, pH, or exposure to chemicals

polysaccharide is

a long chain of monosaccharides; may be branched or unbranched

macromolecules types:

• carbohydrates

• lipids

• proteins

• nucleic acids

subtypes of carbohydrates:

• monosaccharides

• disaccharides

• polysaccharides

Monosaccharides includes:

• Galactose

• fructose

• glucose

Disaccharides includes:

• lactose

• maltose

• sucrose

polysaccharides include:

• Starch

• glycogen

• cellulose

• chitin

lipids include:

• fats

• oils

• waxes

• phospholipids

• steroids

lipids are ______________________.

water fearing and nonpolar

fat molecule includes:

• glycerol

• fatty acids

cation is

a positive ion formed by losing electrons

anion is

a negative ion formed by gaining electrons

triglycerides have ________________.

three fatty acids

Saturated fatty acids are saturated with ____________________________.

hydrogen

unsaturated fatty acid is

the hydrocarbon chain contains a double bond

oils are

unsaturated fats are liquid at room temperature

Enzymes

• break molecular bonds

• to rearrange bonds

• form new bonds

Hormones are

chemical signaling molecules

amino acids make up _______________________.

proteins

nucleotides consist of

• a nitrogenous base

• a pentose (five-carbon) sugar

• a phosphate group

discovery science

• stumble upon

• visit a island and find a new species

hypothesis-driven science

researchers propose a testable explanation, called a hypothesis, to explain a specific phenomenon or observation

What factor of LIFE represents this sentence: bacteria in yogurt quickly multiplies to a very high number of cells

reproduction

What factor of LIFE represents this sentence: the roots of your tomato plant grow towards the leaky water line just outside your garden bed

response to stimuli

What factor of LIFE represents this sentence: your tomato plants make their own food via photosynthesis

energy processing

What factor of LIFE represents this sentence: you are 1.5 cm taller than you were in 10th grade

growth and development

What factor of LIFE represents this sentence: you step out to weed the garden on a hot day and begin to sweat

homeostasis

What factor of LIFE represents this sentence: your kidneys that help excrete waste from your blood are made up of many specialized cells

order

What factor of LIFE represents this sentence: a squirrel keeps eating your tomatoes off the vine

energy processing

What factor of LIFE represents this sentence: your mitochondrial DNA is an exact match to your biological mothers’ mitochondrial DNA

reproduction

What factor of LIFE represents this sentence: you eat too many waffle fries at Chick-fil-a, your blood pressure rises until you eliminate the excess salt in your urine

regulation

What factor of LIFE represents this sentence: the lymph nodes just under your skin provide an ideal environment for your immune system to encounter invading pathogens where specialized cells destroy them

order

where are hydrogen and polar covalent bonds?