Chapter 47

Question 1

vitelline envelope

Answer 1

• Glycoprotein
  outside the cell membrane

Question 2

zona
pellucida

Answer 2

Humans have a thickened
vitelline envelope called a

Question 3

• Fertilization

Answer 3

joins a sperm and an
egg to form a diploid zygote

Question 4

external fertilization

Answer 4

individuals
release their gametes into their
environment

Question 5

• Internal fertilization

Answer 5

Males may package sperm into a
spermatophore, which is placed in the
female’s reproductive tract by the
male or female

Question 6

spermatophore

Answer 6

male packages his sperm in a protective case and delivers it to the female in different ways

Question 7

• Sperm competition

Answer 7

competition
between sperm from different males
to fertilize a female’s eggs

Question 8

• Cryptic female choice

Answer 8

In some species, females choose which
male will fertilize her eggs by
manipulating sperm storage or
physically eject sperm from
undesirable males

Question 9

Formation of Germ Layers (Gastrulation)

Answer 9

Ectoderm (Outer Layer)

Forms skin, nervous system, eyes, and parts of the mouth/rectum

Mesoderm (Middle Layer)

Develops into muscles, bones, circulatory system, reproductive organs, and connective tissues

Endoderm (Inner Layer)

Becomes digestive, respiratory, urinary, and reproductive tract linings, as well as organs like the liver and pancreas

Each germ layer plays a key role in shaping the body’s structure and function! 😊

Question 10

cleavage

Answer 10

The stage of rapid cell division (step 2)

Question 11

blastula

Answer 11

The mass of dividing cells is called the (step 3)

Question 12

gastrulation

Answer 12

Cells move and rearrange to form three germ layers, creating the gastrula. (step 4)

Question 13

Fertilization first

Answer 13

Activates development, starting with a single cell (step 1)