Organisms Grow Flashcards
When do animals’ growth rates often stop?
When they reach the juvenile stage
What body plan is common in animals?
Determinate body plan
What body plan do plants have?
Indeterminate body plan
What is fertilization?
Answer: Formation of a diploid zygote from a haploid egg and sperm
What are early stages of development often studied in?
Model systems
Which model organisms are used to study early development?
Answer: Sea urchin eggs and sperm
Acrosomal Reaction:
Sperm contact with jelly coat releases
acrosome
What does the depolarization of the egg membrane create?
Answer: Fast block to polyspermy
What happens during the cortical reaction?
Answer: Cortical granules fuse with egg plasma membrane
What does the cortical reaction result in?
Cleavage of receptors and formation of fertilization envelope (slow block)
What does cleavage do to the cytoplasm of a large cell?
Answer: Partitions it into smaller cells called blastomeres
What is the fluid-filled cavity in a blastula called?
Answer: Blastocoel
