Part 10

Question 2

Parasympathetic Nervous System

Answer 2

Rest and Digest”

Question 11

Sexual Reproduction in PLANTS

Answer 11

• life cycles of plants are characterized by ALTERNATION of DIPLOID sporophyte and the HAPLOID gametophyte generation.

Evolutionary trend has been towards INCREASED dominance of the SPOROPHYTE generation.

Question 12

Gametophyte Generation

Answer 12

HAPLOID gametophyte generation produces GAMETES by MITOSIS.

Union of female and male gametes at fertilization restores the diploid sporophyte.

Gametophytes reproduce SEXUALLY while the sporophyte reproduces asexually.

Mosses (bracheophyta): gametophyte is the dominant generation.

Question 13

Sporophyte Generation

Answer 13

DIPLOID sporophyte produces haploid spore by MEIOSIS.

Spores divide by mitosis to produce the haploid or gametophyte generation.

e.g. Ferns: Sporophyte is dominant.
Angiosperms: Woody plant seen is sporophyte stage.

Question 14

How is blood type determined?

Answer 14

By three alleles, Ia, Ib, and i.

Only two alleles are present in any single individual, but the population contains all three alleles.

Question 15

Homozygous DOMINANT red snapdragons crossed with Homozygous white snapdragons RECESSIVE gives what in F1 progeny? F2?

What type of dominance is this?

Answer 15

F1 generation will give 100% pink flowers, since generation will give Rr.

F2 will give 1:2:1 progeny in this ratio.
(red, pink, white)

Pink color is result of the combined effects of the red and white genes in heterozygotes.

The type of dominance is called INCOMPLETE dominance because of the pink.

Question 16

Dihybrid Cross

Answer 16

Parents differ in TWO traits.

Question 17

Crossing over

Answer 17

Genes on the same chromosome will stay together unless crossing over occurs.

Exchanges information between chromosomes and may break the linkage of certain patterns. = Mendel’s Law of Indenpendent Assortment

Question 18

TTPP x ttpp = ?

Answer 18

Genotype for all is TtPp and iwll be phenotypically dominant for both traits.

Question 19

TtPp x TtPp = ?

Answer 19

Produces four different phenotypes:

tall purple, tall white, dwarf purple, dwarf white, in the ratio of 9:3:3:1, respectively.

Typical pattern of mendelian inheritance in a dihybrid cross between heterozygotes with independently assorting traits.

Question 20

Curare

Answer 20

Blocks the POST-synaptic ACETYLCHOLINE receptors so that acetylcholine is unable to interact with the receptor.

Leads to PARALYSIS by blocking nerve impulses to muscles.

Question 21

Gibberellins

Answer 21

Stimulate rapid STEM ELONGATION, particularly in plants that normally do not grow tall.

INHIBIT the FORMATION of new ROOTS.

STIMULATE the production of NEW PHLOEM cells by CAMBIUM.

TERMINATE DORMANCY of seeds and buds.

Question 22

Auxins

Answer 22

STIMULATE the production of NEW XYLEM cells.

Important class of plant hormones associated with several growth patterns:

1. Phototropism
   - (growth towards light; Indole acetic acid is one of the auxins associated with phototropism) - MORE auxins = DECREASED growth.
2. Geotropism:
   (Growth TOWARDS or AWAY from gravity)
   - NEGATIVE geotropism = Causes shoot to grow UPWARD, AWAY from acceleration of gravity. (INCREASE in auxin = incerase growth)

• POSITIVE geotropism = Causes roots to grow TOWARDS the pull of gravity. (HIGH concentration of auxin = inhibit growth)

Question 23

Peptide Hormones

Answer 23

SURFACE receptors

Generally act VIA secondary messengers

Question 24

Steroid Hormones

Answer 24

INTRACELLULLAR receptors
Hormone/receptor binding to DNA promotes transcription of specific genes.

e.g. estrogen and aldosterone

Question 25

Gastrointestinal Hormones

Answer 25

1. Gastrin - stimulates secretion of HCl
2. Secretin - released by small intestine and stimulates secreation of bicarbonate to neutralize acidity.
3. Cholescystokinin - released from small intestine in response to presence of fats and causes contraction of gallbladder and release of bile.
4. Bile - involved in digestion of FATS.

Question 26

Calcitonin is released from what gland? what does it do?

Answer 26

Thyroid, decreases calcium concentration in plasma by inhibiting release of Ca2+ from bone.

Question 27

Inducible Systems

Answer 27

REPRESSOR binds to OPERATOR, forming a barrier that PREVENTS RNA polymerase from transcribing the structural genes.

For transcription to occur, the INDUCER must bind to the REPRESSOR forming an inducer-repressor complex. This cannot bind to operator.

Question 28

Repressible Systems

Answer 28

REPRESSOR is INACTIVE until it combines with the COREPRESSOR.

Repressor can bind to operator and PREVENT transcription only when it has formed a repressor-corepressor complex.

Corepressor is END-product since it is being synthesized.

Question 29

Types of Gene Regulation in Prokaryotes

Answer 29

1. Inducible Systems
2. Repressible Systems

Based on accessibility of RNA polymerase.

Directed by OPERON, which consists of structural, operator, and promoter genes.

Question 30

Nondisjunction

Answer 30

Either the failure of homologous chromosomes to separate properly during MEIOSIS I, or the failture of sister chromatids to separate properly during MEIOSIS II.

Can result in trisomy (2N +1) or Monosomy (2N -1).

e.g. trisomy is down syndrome (chr. 21)

Question 31

Sickle-Cell anemia

Answer 31

Disease in which red blood cells become crescent-shaped because defective hemoglobin.

Carries less oxygen.

Caused by SUBSTITUTION of VALINE (GUA or GUG) for GLUTAMIC ACID (GAA or GAG).

Question 32

Reagents used to effect Markovnikov addition to an alkene

Answer 32

H2O/Cl2
Hg(OAc)2/H2O then NaBH4
H2O/H2SO4

Question 33

Antiaromatic

Answer 33

A cyclic, conjugated polyene that possesses 4n electrons.

Question 34

Permutations

Answer 34

p = q! (q - r)!

When working with problems in which items are taken from a larger set in SPECIFIC ORDER.

q = represent a set of items 
r = objects taken r at a time in specific order.

Question 35

Combinations

Answer 35

qCr = q! / [r!(q - r)!]

Possible number of combinations = qCr