final exam

Question 1

what are the 7 characteristics of all living organisms?

Answer 1

1. composed of cells
2. complex and ordered
3. respond to their environment
4. can grow, develop, and reproduce
5. obtain and use energy
6. maintain internal balance
7. allow for evolutionary adaptation

Question 2

what are the levels of cells, organisms, and populations that a biologist can study?

Answer 2

cells
atoms –> molecule –> macromolecule –> organelle –> cell
organisms
tissue –> organ –> organ system –> organism
populations
population –> species –> community –> ecosystem –> biosphere

Question 3

explain the scientific method and its components

Answer 3

• observation
• hypothesis formation
• prediction
• experimentation
• conclusion

Question 4

properties of water

Answer 4

1. water has a high specific heat
2. water has a high heat of vaporization
3. solid water is less dense than liquid water

Question 5

define isotopes

Answer 5

• atoms of a single element that possess different numbers of neutrons
• radioactive isotopes are unstable and emit radiation as the nucleus breaks up

Question 6

define isomers

Answer 6

two or more compounds with the same formula but a different arrangement of atoms in the molecule and different properties.

Question 7

define dehydrogenation

Answer 7

a hydrogen atom is lost (1 electron, 1 proton)

Question 8

aerobic respiration

Answer 8

final electron receptor is oxygen
C₆H₁₂O₆+ 6O₂ –> 6CO₂+6H₂O

Question 9

anaerobic respiration

Answer 9

final electron acceptor is an inorganic molecule (not O₂)

Question 10

fermentation

Answer 10

final electron acceptor is an organic molecule

Question 11

photosynthesis equation

Answer 11

6CO₂+ 12H₂O –> C₆H₁₂O₆+ 6H₂O +6O₂

Question 12

oxygenic photosynthesis is carried out by:

Answer 12

• cyanobacteria
• 7 groups of algae
• all land plants - cholorplasts
• only 1% of the solar energy that reaches the earth is captured by photosynthesis

Question 13

eukaryotic cell cycle

Answer 13

1. G₁ (gap phase 1)
   - primary growth phase, longest phase
2. S (synthesis)
   - replication of DNA
3. G₂ (gap phase 2)
   - organelles replicate, microtubules organize
4. M (mitosis)
   - subdivided into 5 phases
5. C (cytokenesis)
   - separation of 2 new cells

interphase is steps 1-3

Question 14

parts of mitosis

Answer 14

1. prophase
2. prometaphase
3. metaphase
4. anaphase
5. telophase

Question 15

cytokinesis in animal cells

Answer 15

• cleavage of the cell into equal halves
• animal cells – constriction of actin filaments produces a cleavage furrow

Question 16

meiosis division

Answer 16

meiotic cells have an interphase similar to mitosis. After interphase, germ-line cells enter meiosis 1.

prophase 1 & 2
metaphase 1 & 2
anaphase 1 & 2
telophase 1 & 2

Question 17

mendel’s experimental method

Answer 17

1. produce true-breeding strains for each trait
2. cross-fertilize true-breeding strains having alternate forms of a trait
3. allow the hybrid offspring to self-fertilize for several generations and count the number of offspring showing each form of the trait

usually 3 stages

Question 18

F₁ generation

Answer 18

• first filial generation
• offspring produced by crossing 2 true-breeding strains
• for every trait mendel studied, all F₁ plants resembled only 1 parent
  
  • referred to this trait as dominant
  • alternative trait was recessive

Question 19

F₂ generation

Answer 19

• second filial generation
• offspring resulting from the self-fertilization of F₁ plants
• although hidden in the F₁ generation, the recessive trait had reappeared amoong the some F₂ individuals
• Always found to be 3:1 ratio

Question 20

principle of segregation

Answer 20

• “mendel’s first law of heredity”
• 2 alleles for a gene segregate during gamete formation and are rejoined at random, 1 from each parent, during fertilization
• physical basis for allele segregation is the behavior of chromosomes during meiosis
• mendel didn’t know abt chromosomes or meiosis

Question 21

dihybrid crosses

Answer 21

• examination of 2 separate traits in a single cross
• mendel produced true-breeding lines for 2 traits
• the F₁ generation of a dihybrid cross shows only the dominant phenotypes for each trait
• allow F₁ to self-fertilize to produce F₂

Question 22

polygenic inheritance

Answer 22

more than one gene can affect a single trait
(ex. 4 genes are involved in determining eye color)

Question 23

pleiotropy

Answer 23

a single gene can affect more than one trait
(ex. cystic fibrosis)

Question 24

phosphodiester bond

Answer 24

• bond between adjacent nucleotides
• formed between the phosphate group of 1 nucleotide and the 3’ OH of the next nucleotide
• the chain of nucleotides has a 5’ to 3’ orientation

Question 25

central dogma

Answer 25

* francis crick * information only flows from: DNA --> RNA --> protein * transcription = DNA --> RNA * translation: RNA --> protein * retroviruses violate this order using reverse transcriptase to convert their RNA genome into DNA (ex. HIV)

Question 26

gel electrophoresis

Answer 26

* separate DNA fragments by size * submersed in buffer that can carry current * negatively-charged DNA migrates towards the positive pole * larger fragments move slower, smaller move faster

Question 27

polymerase chain reaction

Answer 27

* allows the amplification of a small DNA fragment using primers that flank the region Each PCR cycle involves three steps: 1. denaturation (high temperature) 2. annealing of primers (low temperature) 3. DNA synthesis (intermediate temperature)

Question 28

quantitative RT-PCR

Answer 28

* reverse transcription quantitative PCR involves isolating mRNA, converting to cDNA using RT, then using PCR to amplify specific cDNAs * amount of DNA produced can be measured in real time by the PCR machine * can be found with DNA-binding dyes and probes

Question 29

genetic engineering

Answer 29

* expressions vectors contain the sequences necessary to express inserted DNA in a specific cell type * transgenic animals contain genes that have been inserted without the use of conventional breeding (mouse eyeless gene worked to organize eye formation in *Drosophila*

Question 30

CRISPR/Cas9 system

Answer 30

* a guide RNA targets Cas9 to a gene that matches the guide RNA sequence * Cas9 can cut the DNA with which it is associated * DNA can be repaired: double-stranded DNA containing a mutation can be provided to replace normal gene sequence * Cas9 can also be targeted to activate or repress gene expression

Question 31

gene therapy

Answer 31

* adding a functional copy of a gene to correct a hereditary disorder * severe combined immunodeficiency disease (SCID) illustrates both the potential and the problems (15 treated successfully, 3 developed leukemia)

Question 32

knockout and transgenic organisms

Answer 32

* transgenic organisms are all or part transformed cells * ADD MORE HERE

Question 33

# unifying themes in biology cell theory

Answer 33

* all organisms are composed of cells * cells are life's basic units * all cells come from preexisting cells

Question 34

# unifying themes in biology molecular basis of inheritance

Answer 34

* deoxyribonucleic acid (DNA) * sequence of 4 nucleotides encode cell's info * gene: discrete unit of info * genome: entire set of DNA instructions * continuity of life depends on faithful copying of DNA into daughter cells

Question 35

what are the four components of the cellular membrane?

Answer 35

1.phospholipid bilayer 2.interior protein network 3.transmembrane proteins 4.cell surface markers.

Question 36

define symporters and antiporters

Answer 36

symporters: a membrane transport protein that facilitates the movement of two different molecules across the cell membrane in the same direction. antiporters: ^ different directions