1. BIOLOGY IS CONTAGIOUS

2. 116 THINGS YOU NEED TO KNOW TO PASS THE MCAS
BIOLOGY EXAM

3. are mostly made of the elements C,H,O,N,P, and S
Living things
are mostly made of the elements C,H,O,N,P, and S
Organic compounds contain carbon
Four important macromolecules are carbohydrates,
lipids, proteins,
and nucleic acids
Polymers are long chains of monomers

4. The monomer of a protein is an amino acids
The monomer of a nucleic acid is a nucleotide
A nucleotide consists of a sugar, a phosphate group, and a nitrogenous base
The function of a carbohydrate is to provide a cell with energy

5. Nucleic acids store genetic information for cells
Lipids store energy and are a component of cell membranes and are used to produce hormones
Proteins have a variety of functions in the cell and make up muscles, hair, and nails
Enzymes are proteins that speed up chemical reactions (also known as catalysts)
Nucleic acids store genetic information for cells

6. In a chemical reaction, reactants combine/change to form products
Substrates fit into the active site of an enzyme like a “lock in a key”
A substrate is a reactant in an enzyme-catalyzed reaction
Enzymes work by lowering the activation energy of a chemical reaction

7. Organelles are the parts of a cell
Two things that affect enzyme function are temperature and the pH(acid/base) of a solution
Organelles are the parts of a cell
Prokaryotes do not have a nucleus; eukaryotes do
Plant cells contain cell walls, large vacuoles, and chloroplasts

8. DNA is found within the nucleus in a eukaryotic cell
Animal cells lack a cell well, never have chloroplasts, and contain centrioles
DNA is found within the nucleus in a eukaryotic cell
Chloroplasts are green and capture sunlight energy to make sugar (glucose) for cells
Mitochondria produce energy (ATP) for cells

9. Ribosomes are the site of protein synthesis
The endoplasmic reticulum and the Golgi bodies work together to modify and ship proteins
Ribosomes are the site of protein synthesis
The cell wall of a plant is made of a carbohydrate (cellulose) and gives plant their rigid shape
The cytoskeleton gives the cell shape and structure

10. Cell membranes are found in all cells and are made of a
semi-permeable
lipid bilayer
Pump and channel proteins are also found in the cell membrane
Active transport uses energy (ATP) to move molecules from
low concentration
to high conc.
Active transport requires protein pumps

11. Facilitated diffusion uses protein channels to move molecules from high conc.
to low conc.
Diffusion moves small molecules through a membrane from high conc. to low conc.
Osmosis is the diffusion of water molecules through a semi-permeable membrane
Photosynthesis: 6H2O +6CO2 + light  C6H12O6 +6O2 (occurs in chloroplast)

12. Cellular Respiration: C6H12O6 +6O2  6H2O +6CO2 + ATP (occurs in mitochondria)
Energy in a molecule of ATP is stored in the bonds between phosphate groups
The stages of cell division (mitosis) are prophase, metaphase, anaphase, and telophase
Cytokinesis causes a cell to divide in two. Animal cells pinch, plant cells assemble membrane and wall

13. Fertilization is when sperm cells and egg cells join together
Gametes (sperm/egg) are made through a two rounds of reductive division called meiosis
After mitosis, there is an equal number of chromosomes in each cell (diploid)
After meiosis, there is half the normal amount of chromosomes in each cell (haploid)
Fertilization is when sperm cells and egg cells join together

14. Crossing over in meiosis helps increase genetic variation in offspring
DNA stores protein instruction in a sequence of nitrogenous bases called a gene
The sugar-phosphate backbone gives the DNA molecule structure
DNA is a double stranded molecule with a deoxyribose sugar

15. RNA is a single stranded molecule with a ribose sugar
A pairs with T and U ; G pairs with C
Three types of RNA: messenger, ribosomal, and transfer
RNA contains U instead of T

16. Replication is when DNA makes an exact copy of itself
Transcription is when a gene is copied onto mRNA
Translation is when the mRNA transcript is used to make a polypeptide (protein)
Mutations can alter a DNA sequence, sometimes (not always) causing a change in the protein

17. The phenotype is what an organism physically looks like
The genotype is what copies of a gene an organism has
Alleles are different versions of a gene
Dominant alleles mask recessive alleles

18. A heterozygous individual has two different alleles
A homozygous individual has two of the same alleles
Blended phenotypes (red + white = pink) show that the alleles are incompletely dominant
Mixed phenotypes (orange + blue = orange and blue) show codominant alleles

19. Evolution is change over long periods of time
Polygenic traits are controlled by more than one gene and show a normal (bell) distribution
Evolution is change over long periods of time
Natural selection states that the best adapted individuals will survive and pass on their genes
Evidence for evolution is shown in fossils, DNA sequences, embryology, and homology

20. Speciation occurs when gene pools become separated over long periods of time
Genetic variation among organism comes from crossing over and mutations
Organisms are classified by the kingdom, phylum, class, order, family, genus, species system
All organisms are descended with changes from an ancient, common ancestor

21. The three domains are eukarya, archea, and bacteria
Polygenic distribution curves can undergo stabilizing, disruptive, or directional selection
The three domains are eukarya, archea, and bacteria
The six kingdoms are archeabacteria, eubacteria, animalia, plantae, fungi, protista
Evolutionary relationships are based on DNA sequences NOT physical appearance

22. The deeper in a rock layer a fossil is found, the older that
Population size is affected by birth rates, death rates, and migration rates.
Carrying capacity is the maximum number of individuals an ecosystem can support
Limiting factors dictate the size of a population

23. Producers are autotrophs – they make their own food
Ecological organization: species – population – community – ecosystem – biome - biosphere
Producers are autotrophs – they make their own food
A food web shows all of the feeding relationships in a particular ecosystem
Consumers are heterotrophs – they eat their food

24. Energy arrows always flow from the producers to the consumers
Only 10% of the available energy is transferred to the next trophic level
The main source of energy for living things is the sun
Herbivores are primary consumers

25. Carbon enters the biosphere through photosynthesis
Carbon is returned to the atmosphere by breathing (respiration) and the burning of fossil fuels
Carbon enters the biosphere through photosynthesis
Bacteria fix nitrogen gas into a form usable by living organisms (nitrogen fixation)
Parasitic relationships involve one organism benefiting and the other organism suffering

26. Mutual relationships show a benefit for both organisms
Commensalism shows a benefit for one organism, and no effect for the other
Mutual relationships show a benefit for both organisms
Homeostasis works via feedback loops and maintains a constant internal environment
Carbohydrates, fat, and protein are all important sources of energy and nutrition

27. Nutrients are absorbed into the blood by the small intestines
The stomach and mouth digest (break down) food into smaller molecules using enzymes
Nutrients are absorbed into the blood by the small intestines
Blood is a suspension of red blood cells, white blood cells, plasma, and platelets
The kidneys filter waste materials out of the blood

28. The heart pumps blood throughout the body
Red blood cells carry oxygen, white blood cells fight infection, and platelets clot blood
The heart pumps blood throughout the body
Veins carry blood to the heart (low oxygen) and arteries carry blood to the body (high oxygen)
Lungs contain tiny sacs called alveoli

29. Air enters the lungs via the trachea (windpipe)
Oxygen diffuses into the blood and carbon dioxide diffuses out of the blood at the alveoli
Air enters the lungs via the trachea (windpipe)
The bolus (mashed food and saliva) enters the stomach via the esophagus
The nervous system allows the body to communicate and coordinate functions

30. There are three types of muscle: skeletal, smooth, and cardiac
Neurons consist of a long axon, several short dendrites, and a cell body
The endocrine system sends chemical signals (hormones) throughout the body
There are three types of muscle: skeletal, smooth, and cardiac
Muscles allow the body to move

31. Bones provide structure and a site for mineral storage
Red blood cells are made in bones
Viruses are made of a protein coat and genetic material (DNA/RNA). They are not alive!
Nerve use electrical impulses and chemical (neurotransmitters)
to communicate