Download presentation
1
INSECT DEVELOPMENT
2
Spermatogenesis Germarium Zone of Growth Zone of Maturation
Zone of Transformation N N N N
3
Oogenesis Ovum Oogonium Mitosis to produce more germ cells
Onset of meiosis I Primary oocyte (meiosis I prophase - arrested - present at birth) 2N Complete meiosis I First polar body N Secondary oocyte (arrested at metaphase of meiosis II) Ovulation Ovum Second polar body N
4
Structure of Egg polar granules micropyle yolk spheres
nuclear cytoplasm aeropyle chorion nucleus periplasm (cytoplasm) polar granules vitelline membrane
5
aeropyles micropyle
6
Sperm Transfer 1. Spermatophore
7
spermatophore sperm nutrients for female
8
Does female actually get the nutrients?
Spermatophore takes up radioactive protein Inject male with radioactive protein Spermatophore passed to female Eggs contain radioactive protein
9
Sperm Transfer 2. Direct intromission
10
Sperm Transfer 2. Direct intromission Penes of male Argia (Odonata)
11
Sperm Transfer 3. Traumatic (Haemocoelic) insemination
12
Development - Fertilization
Syncytial blastoderm germ cells
13
Development - Germ Band Formation
Blastoderm cells migrate ventrally Germ band
14
Insect Development - Gastrulation
1 ectoderm mesoderm 2 3 germ band
15
Amnionic sac Midgut rudiments 2 1 dorsal closure neuroblasts 3 4
16
Gastrulation in Tribolium
Stage 2 -3 from previous slide
17
Heart endoderm Ectoderm mesoderm Gut fat body Hemocoel tracheal invagination somatic muscles Ventral nerve cord
19
Fate of the Germ Layers cleavage energids blastoderm pole cells
ectoderm mesoderm endoderm midgut stomodeum proctodeum epidermis trachea salivary glands mesodermal bands neuroblasts CNS gametes gonad visceral muscles somatic muscles fat body heart
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.