Biology 100 Final Exam Study Guide

What is a scientific theory?

A scientific theory is a well-substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experiment.

What is the correct order of complexity?

Atom, Molecule, Organelle, Cell, Tissue, Organ, System, Organism, Population, Community, Ecosystem, Biosphere

What is the definition of a population?

Members of a single type of living thing, living together in a defined area

What is homeostasis?

Maintaining a constant internal environment

What is the definition of a tissue?

A large mass of similar cells that make up a part of an organism and perform a specific function.

Living things inherit information from their parents encoded in what?

DNA

What are the subatomic particles of an atom?

protons, neutrons, and electrons

Which subatomic particle plays the greatest role in chemical reactions?

electrons

Why will atoms react with other atoms?

their outermost shell of electrons has not been filled

What is the definition of a hydrophobic molecule?

A molecule that is repelled by water or is "water-fearing".

How many covalent bonds can oxygen make with hydrogen?

two

What is the definition of a solute? Solvent?

A solute is the substance to be dissolved (example: sugar). The solvent is the one doing the dissolving (example: water).

What is the definition of an acid (in regards to hydrogen atoms)?

Acids are substances that can donate H+ ions to bases.

What is glycogen?

a substance deposited in bodily tissues as a store of carbohydrates. It is a polysaccharide that forms glucose on hydrolysis.

What is a polysaccharide?

a carbohydrate (e.g., starch, cellulose, or glycogen) whose molecules consist of a number of sugar molecules bonded together

What is a phospholipid?

two fatty acids, attached to a glycerol 'head' and a phosphate group. they are located in the phospholipid bilayer and have a hydrophilic (or 'water loving') head and a hydrophobic (or 'water fearing') tail.

What are the functions of proteins?

Quickening chemical reactions, chemical messengers, repair and maintenance, energy, hormones, enzymes, transportation and storage of molecules, and forming antibodies, healing, mechanical support, storing nutrients, cell signaling.

What are proteins made up of?

amino acids

What is DNA made up of?

nucleotides

What are the organelles found in an animal cell?

nucleus, nuclear membrane, cytoplasm, rough and smooth endoplasmic reticulum, mitochondrion, lysosome, Golgi body, ribosome

What is the boundary of an animal cell called?

cell membrane

What is the main function of the nucleus?

Its main function is to regulate gene expression; it also controls cellular growth and replication.

What is the main function of ribosomes?

making proteins

What is the main function of the cytoskeleton?

provides structural support

What are found in plant cells and not animal cells?

chloroplasts, central vacuoles, and cell walls

What is the purpose of the plasma membrane?

It regulates what enters and exits the cell.

Are the fatty-acid tails of a phospholipid hydrophilic or hydrophobic?

hydrophobic

What part of the plasma membrane helps keep it fluid?

cholesterol

What needs to be present for something to move passively through a cell membrane?

concentration gradient

What is the difference between passive and active transport?

passive transport does not require energy while active energy does. In the case of active transport, the molecules move against the concentration gradient from low to high concentration.

What is entropy?

the measure of "disorder" in a system

(everything is constantly getting more and more disordered)

What is an example of potential energy? Kinetic Energy?

An example of potential energy is a gun about to go off or a rock at the top of a hill. Kinetic energy would be those objects in motion, such as a gun shooting or a rock rolling down a hill.

What is the First Law of Thermodynamics?

the Law of Conservation of Energy, states that energy cannot be created or destroyed in an isolated system.

What is the energy currency of cells called?

ATP

What type of organic molecule makes up enzymes?

Enzymes are organic molecular proteins composed of amino acids

What are the four bases in DNA?

A, T, G, and C

(Adenine, Thymine, Guanine, and Cytosine)

What is an estimate number of the genes in the human genome?

20,000-25,000

What is being separated during anaphase of mitosis?

sister chromatids

If a cell contains 30 chromosomes, how many chromatids will be present during prophase?

60

(the chromosomes have doubled to get ready to split into two cells)

What is the difference between animal cell division and plant cell division?

in plant cytokinesis, a new cell wall is fashioned between the new daughter cells, while in animal cells the cell membrane constricts to pinch the parent cell into daughter cells.

What is binary fission?

After replicating its genetic material, the cell divides into two nearly equal sized daughter cells. The genetic material is also equally split. (it is the most common form of asexual reproduction in prokaryotes and some single celled eukaryotes)

How many chromosomes are in a human gamete?

23

What are the products of meiosis? How are they different than the products of mitosis?

meosis produces 4 unique haploid daughter cells, while mitosis produces 2 identical diploid daughter cells.

What steps in meiosis contribute to genetic diversity?

crossing over, random chromatid assortment, and fertilization

What is an autosome?

any chromosome that is not a sex chromosome (in humans, our first 22 chromosomes are autosomes)

A human egg contains how many and what kind of chromosomes?

23 chromosomes (22 autosomes and 1 sex (x) chromosome)

An X chromosome from the mother and a Y chromosome from the father makes what?

a male

What is the phenotype of an organism?

the visible characteristics determined by the genotype

What is an example of incomplete dominance?

red and white flowers mixing to make pink ones

What is an example of a heterozygous genotype?

Hh (one dominant and one recessive allele)

Which type of dominance is most likely to display a bell curve of phenotypes?

polygenic inheritance

(example: height, weight, etc)

Who is a "carrier" of X-liked disorders, such as hemophilia and color blindness?

a heterozygous female who is normal but carries one nonfunctioning allele?

Why do X-linked conditions appear more frequently in males than females?

women have two x chromosomes, so one can cancel out the faulty gene, whereas males have only one x chromosome.

What is sickle-cell anemia?

a severe hereditary form of anemia in which a mutated form of hemoglobin distorts the red blood cells into a crescent shape at low oxygen levels. It is most common among those of African descent.

What is hemophilia?

a medical condition in which blood cannot sufficiently clot and slight injuries cause severe bleeding.

What disease is commonly caused by aneuploidy?

Down Syndrome

What helped determine the DNA was a double-helix structure?

X-ray diffraction

What units are bonded together to make a strand of DNA?

Bases: A,T, G, C

How many different types of bases are there in DNA?

4

Be able to replicate a sequence of bases of DNA.

A bonds to T and G bonds to C. (In MRNA, T changes to U)

What is the definition of a mutation?

A change in the structure of a gene caused by the change of a single base (when it isn't corrected)

How many different types of amino acids are there?

20

What is the most critical feature in a protein that determines its function?

Shape (bends)

What are monomers of proteins?

Amino acids

What is a codon?

A sequence of three nucleotides that form a genetic code in DNA or RNA.

Be able to make a strand of mRNA from a sequence of DNA.

A to U, G to C

What is the first amino acid of a new polypeptide chain?

Met

What two taxons are used to represent the organism?

Genus and species

How do you properly write the genus and species of an organism?

First letter capitalized in genus, all the rest lower case, all italics

What is the correct order for taxons of life?

Life, domain, kingdom, phylum, class, order, family, genus, species

What is Taxonomy?

The branch of science concerned with classification

What is a heterotroph? Autotroph?

A heterotroph eats its food for energy and an autotroph makes its own food for energy (photosynthesis)