W10 L1

Question 1

What is allometry?

Answer 1

difference in growth rates of different body parts

causes change in body proportionality

Question 2

What is heterochrony?

Answer 2

changing in the timing of events

Question 3

What is paedomorphy? Ex.?

Answer 3

condition of an adult organism retaining juvenile features

ex. axolotl

Question 4

What is considered the ancestral condition for vertebrates?

Answer 4

ovuliparity

Question 5

What is ovuliparity?

Answer 5

eggs are released by the female into the environment and fertilized externally by the male
common in fish and many frogs

Question 6

What is the important part of egg development where there is the deposition of the yolk in each ovum?

Answer 6

vitellogenesis

Question 7

in ovuliparity, is the yolk in each ovum enough to maintain development of the embryo?

Answer 7

yes

Question 8

What is oviparity?

Answer 8

fertilization is internal but female lays zygote as eggs outside body

Question 9

Why are eggs are generally large?

Answer 9

the yolk needs to last the zygote through metamorphosis into a juvenile organism

Question 10

How much space does the yolk take up in an egg?

Answer 10

20-70% volume

Question 11

What does albumin contain in the egg?

Answer 11

carbohydrates and water that help sustain the embryo

Question 12

why is the shell rigid?

Answer 12

egg made up of 98% crystalline calcite which is where the embryo gets most of its calcium

Question 13

Why is the egg able to have passive gas exchange and allow for moisture to leave?

Answer 13

shell is porous

Question 14

What creates an air cell at the blunt end of the egg?

Answer 14

as embryo grows, shell becomes thinner and water is lost

Question 15

What is ovoviviparity? Ex.?

Answer 15

internal fertilization & zygote retained in body. but parent doesn’t provide zygote with any sustenance
ex. seahorses

Question 16

What type of reproduction is present in lots of sharks?

Answer 16

histotrophic viviparity

Question 17

do females in histotrophic viviparity provide sustenance to the zygotes developing in their oviduct due to internal fertilization?

Answer 17

NO

Question 18

How do zygotes in histotrophic viviparity obtain nutrition?

Answer 18

through other tissues like skin, oophagy, or from adelphophagy

Question 19

what is adelphophagy?

Answer 19

consumption of other embryos in the womb

Question 20

How are nutrients provided in hemotrophic vivaparity?

Answer 20

through a placenta

Question 21

What is the period of time required for full development of fetus in utero from fertilization of the egg to birth called?

Answer 21

gestation

Question 22

When do cells go from totipotent to multipotent in embryogenesis?

Answer 22

during gastrulation, when the three germ layers form

Question 23

What is the primitive streak?

Answer 23

an indentation along the dorsal surface of the epiblast during embryogenesis

Question 24

Where in the embryo does it secrete growth factors that direct cells to multiply and migrate?

Answer 24

a node at the tail end of the primitive streak

Question 25

What cells displace the hypoblast and lie adjacent to the yolk sac?

Answer 25

endoderm cells

Question 26

does the cells of the epiblast become the mesoderm?

Answer 26

NO, they remain and form the ectoderm

Question 27

What are the first three layers of cells in the embryo an example of?

Answer 27

Modules

Question 28

What are modules?

Answer 28

set of cells or set of genes that are intrinsically related to each other than to their surroundings

Question 29

What are modules related to?

Answer 29

Pleiotropy

Question 30

What is pleiotropy?

Answer 30

state where a single gene controls multiple traits