insect sex development

Question 1

hox genes

Answer 1

control the subdivision of embryos into regions of different developmental fates along the anteroposterior axis

-homologous in diverse organisms
-are the master genes that control expression of subordinate genes

Question 2

homeobox

Answer 2

-highly conserved amino acid coding sequence shared among hox genes, that binds DNA
-regulate the transcription of other genes, typically the genes that are a part of gene cascades involved in development

Question 3

transcription factor

Answer 3

a protein that, by interacting with a regulatory DNA sequence, affects the transcription of the associated gene

Question 4

homeotic selector genes

Answer 4

control patterning of body structures

Question 5

how is position-specific expression achieved?

Answer 5

HOX genes then trigger cascades of developmental gene pathways (via TF’s)

Question 6

mating (basic ways)

Answer 6

swarming, sex pheromones, territorial display/fighting, courtship display, no idea

Question 7

Swarming

Answer 7

aggregate in large noise group
use different landmarks to attract attention (edges, treefalls, mountain tops, food plants)

midges, mayflies, honeybees, some mosquitoes

Question 8

sex pheromones (how work)

Answer 8

attract by secretion from abdomen or wings
detect by antennae
long distance
found in silk moths, beetles, wasps

Question 9

courtship offerings

Answer 9

offer food or fake food in silk wrapping

-prevents interspecific mating
-uses structural modifications, territorial display, behavior

Question 10

aggressive display

Answer 10

some male beetles may have enlarged jaws or horns for fighting with other males for females

Question 11

sexual parasitism

Answer 11

males mating with flowers

Question 12

shape of plant feeders ovipositor

Answer 12

needle-like

Question 13

parasitic wasp oviposition

Answer 13

melt their way through wood using cellulases from accessory gland, push egg through tube, egg deforms from oval to hotdog shape

Question 14

wasp and bee ovipositor

Answer 14

used defensively or offensively, not for egg laying, egg emerges alongside sting

Question 15

solitary wasp sting function

Answer 15

prey capture or defense

Question 16

social wasp sting function

Answer 16

capture prey, defend nest against vertebrates, not for feeding

Question 17

HETEROSYNTHETIC VITELLOGENESIS

Answer 17

help

Question 18

oviparity

Answer 18

lay eggs externally

Question 19

ovoviparity

Answer 19

retain eggs internally, they hatch inside, mother lays larvae externally

Question 20

viviparity

Answer 20

embryos develop free in females haemolymph, partially developed embryo hatches from egg and develops in placenta like organ in female (tsetse fly)

Question 21

ametabolous

Answer 21

looks the same through almost all stages (no metamorphosis)

Question 22

hemimetabolous

Answer 22

half of metamorphosis (body similar to adult stage, but it wingless) and gains wings at last stage of development

Question 23

holometabolous

Answer 23

complete metamorphosis

Question 24

juvenile hormone

Answer 24

terpene

Question 25

20-hydroxyecdysone

Answer 25

steroid (insects can’t make sterols)

Question 26

cuticle layers from outside exposed layer to internal

Answer 26

epicuticle, exocuticle, endocuticle, epidermal cell layer

cuticle is all but cell layer
procuticle is exo/endocuticle

Question 27

molting cycle

Answer 27

1. mitosis (division) of epidermal cells
2. apolysis (epidermal cell separation from overlying cuticle)
3. molting fluid secreted (inactive tho)
4. epicuticle produced (protects epidermis)
5. molting fluid activated (digests endocuticle)
6. new procuticle produced beneath the outer epicuticle
7. ecdysis (shedding of old exoskeleton)
8. sclerotization of procuticle to form new exocuticle

Question 28

when to molt?

Answer 28

size big enough -> juvenile hormone cleared from hemolymph -> photoperiod ‘gate’ open-> secrete PTTH and ecdysone -> stop eating/growing and begin metamorphosis

Question 29

PTTH

Answer 29

made in brain, released from corpora cardiaca

Question 30

where is ecdysone produced?

Answer 30

prothoracic gland

Question 31

where is the juvenile hormone made?

Answer 31

brain (corpora allatum), also serves as a yes/no switch that tells cells what type of molt to do

Question 32

what are the two types of molt and what conditions determine the type of molt?

Answer 32

Ecdysone in the presence of JH produced by the corpora allata leads to an isometric molt and in the absence of JH to an anisometric molt.