Chapter 12: Part 2

Question 1

Understand gas exchange through the shell

Answer 1

• oxygen travels through shell membrane, all the way to the inner membrane, to create oxygenated blood as carbon dioxide leaves the opposite way through the cuticle of shell
• chorioallantoic membrane allows oxygen in and carbon dioxide out through porous shell, goes through checkpoint at allantois

Question 2

Understand How the amount of yolk varies with developmental strategy

Answer 2

• less yolk content means precocial, less developed at hatching; will need more help to survive(bohemian waxwing)
• more yolk content means more developed at hatching, Altricial (ex: Brown Kiwi)

Question 3

Describe the variation in egg size, shape, and color

Answer 3

• surfaces can be pitted, chalky, glossy
• coloration can help with camouflage in wild, avoid predation
• shape can protect egg in its habitat

Question 4

Example of egg shape adaptation

Answer 4

• Common Murres eggs are created to roll on one end and hold position on the other, prevents rolling off cliffside habitat

Question 5

Name four stages of egg development in oviduct

Answer 5

• Infudibulum
• magnum
• isthmus
• Uterus

Question 6

Infundibulum

Answer 6

• site of fertilization

Question 7

Magnum

Answer 7

• first layer of albumen added

Question 8

Isthmus

Answer 8

• inner membrane, outer shell membrane, and albumen added

Question 9

uterus

Answer 9

• shell gland (albumen, shell, and pigments added)
• uterovaginal junction (location of sperm storage tubules)
• egg sits near vagina cloaca

Question 10

What happens to the cloaca during egg laying?

Answer 10

• Part of the cloaca and the last segment of
  the oviduct turned inside out
• The vent is then everted
• The egg does not contact the walls of the cloaca and get contaminated by feces
• The intestine and inner part of the cloaca are kept shut by the emerging egg

Question 11

Describe how embryos grow

Answer 11

• the blastoderm is going to form multiple dermis type layers
• the yolk sac will help the amnion grow and the allantois helps it breathe during development
• albumen slowly decreases, takes up less space

Question 12

Captial breeders

Answer 12

• Draw heavily on stored energy and
  nutrient reserves to produce their
  large, expensive egg

Question 13

Income breeders

Answer 13

ingest on a daily basis the resources
that they need for egg production