Lecture 1 - The Cell

Question 1

Classification system

Answer 1

Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species

Question 2

All mammals belong to the class _________ and the phylum __________

Answer 2

Mammalia; Chordata
birds are in Chordata too but in class Aves

Question 3

Kingdoms in Eukarya

Answer 3

Protista, Fungi, Plantae, Animalia

Question 4

Species

Answer 4

if can produce fertile offspring with one another

Question 5

Barriers to producing fertile offsprings

Answer 5

• geographic isolation
• temporal isolation (different seasons)
• genetic incompatibility (gametes do not form viable offspring); ex: mule = female horse and male donkey)

Question 6

Cell theory

Answer 6

• smallest basic unit life

- shared by all living things

Question 7

Polymorphism

Answer 7

• gene that has multiple alleles corresponding to distinct forms of a phenotype
• existence in the population makes evolution and speciation possible

Question 8

Gene pool

Answer 8

total of all alleles in a population

-> evolution = change in a population’s gene pool

Question 9

Speciation

Answer 9

• evolution can lead to this

- formation of new species

Question 10

Inbreeding

Answer 10

• mating of relatives
• increases # of homozygous indivs in a population without changing allele frequency
• can lead to speciation (ex: if population divided into groups and mutation occurs in one group but not the other)

Question 11

Bottleneck

Answer 11

• can lead to speciation (randomly)

- when a disaster occurs in which few survivors (allele frequency not representative of original population)

Question 12

Specialization

Answer 12

process by which the members of a species tailor their behaviours to exploit their environment

Question 13

Genetic or behavioural changes that are advantageous in the given environment can lead to speciation

Answer 13

Adaptation

Question 14

Hardy-Weinberg equilibrium

Answer 14

• theoretical population in which no evolution would occur
  1. mutational equilibrium (rate of fwd mutations = back mutations)
  2. large population
  3. random mating (lack of sexual selection)
  4. immigration or emigration must not change the gene pool (no introduction or decline of alleles)
  5. no selection for the fittest organism
• *when one is broken, evolution occurs

Question 15

T or F. Large populations are subject to genetic drift

Answer 15

F, small!

Question 16

Genetic drift

Answer 16

where one allele may be permanently lost due to the death of all members having that allele

Question 17

Driving principle of natural selection

Answer 17

genes that are advantageous in a given environment are preferentially passed down from generation to generation

Question 18

Differential reproduction

Answer 18

giving offspring a better chance to reproduce

Question 19

Viral particle or Virion

Answer 19

mature virus outside host cell

Question 20

Viruses are comparable to …

Answer 20

nuclei of a cell; exploits organelles around it to synthesize protein and metabolize nutrients
when a virus is inside a cell = extra nucleus

Question 21

Structure of a virus

Answer 21

• capsid
• tail, base plate, tail fibers
• nucleic acid
• lipid-rich protein envelope for some

Question 22

Virus following a lytic cycle

Answer 22

virulent; disease-causing

Question 23

Viral envelopes

Answer 23

• made from host cell membrane; through exocytosis
• protects enveloped virus from immune system
• receptors on envelope allow it to bind to a new host cell and start all over again
• original cell doesn’t die right away but due to the degradation of its membrane will eventually die
• unlike nonenveloped viruses where their release does cause the death of host cell (lyse cell)

Question 24

Small rings of naked RNA without capsids, which only infect plants

Answer 24

Viroids

prions in animals (naked proteins)

Question 25

These are capable of reproducing themselves without RNA or DNA

Answer 25

prions

Question 26

Each bacterial phospholipid bilayer is composed of

Answer 26

phosphate group, two fatty acid chains, and a glycerol backbone

Question 27

Protoplast

Answer 27

Bacterial plasma membrane + everything it contains

Question 28

What surrounds the protoplast?

Answer 28

bacterial envelope

Question 29

What does penicillin attack

Answer 29

the amino acid crosslinks of the peptidoglycan

Question 30

Space between plasma membrane and cell wall

Answer 30

periplasmic space

- contain many proteins that help bacteria acquire nutrition, such as hydrolytic enzymes

Question 31

Three forms of genetic recombination allow bacteria to trade DNA

Answer 31

conjugation, transduction, and transformation

Question 32

Bacteria increase by __________ growth

Answer 32

exponential, meaning that each organism produces two offspring, which then produces two offspring and so on

Question 33

Plasmid

Answer 33

regions with extragenomic DNA

- conjugation

Question 34

If the plasmid can integrate into the chromosome, it is called …

Answer 34

an episome

Question 35

F plasmid vs R plasmid

Answer 35

F - fertility factor; codes for the sex pilus

R - donates resistance to certain antibiotics (even different species); also a conjugative plasmid

Question 36

Process by which bacteria incorporate DNA from the external environment into their genomes

Answer 36

Transformation

Question 37

Transposons

Answer 37

• provide a way for nucleotides to move from one position to another
• pieces of DNA capable of ‘jumping’ from one place to another along genome
• transposase catalyzes the transposon’s removal from and incorporation into the chromosome
• one way that genes from a plasmid ca be incorporated into genome