bio 211 exam 2 Flashcards
What happens when two haploid (n) gamete cells fuse together?
What exactly forms?
Diploid (2n) zygote
What does cleavage result in?
a Blastula: hollow ball of cells
When does gastrulation begin?
The Blastopore
What does Gastrulation result in?
The formation of the embryonic germ layers
What do the three germ layers give way to?
The rise of specialized tissues and structures
What do Hox genes do?
- Control whether a segment of the embryo will form part of the head, thorax, or abdomen
- Transcription factor genes
What are the three germ layers?
Ectoderm, mesoderm, and endoderm
What specialized tissue does the Mesoderm make?
Muscles, skeletal tissue, blood vessels
What does the Ectoderm make?
Nervous system, epidermis
What does the Endoderm make?
Digestive and respiratory organs
What is Asymmetry?
No pattern in the body
What is radial symmetry?
Body parts are arranged around a central axis and associated with sessile and limited movement
What is bilateral symmetry?
Body parts are arranged along a central axis and is associated with cephalization
What is Cephalization?
The concentration of nervous tissue at one end of the body, leading to the development of a brain and head
What is a difference between diploblasts and triploblasts?
Diploblasts have two germ layers (endoderm & ectoderm), while triploblasts have three germ layers (endoderm, ectoderm, mesoderm)
What is found in fungi cells but not animal cells?
Cell wall
True or False
Fungi secrete enzymes to break down decaying matter, which releases nitrogen, phosphorus, and carbon dioxide into the the ecosystem
True
True or False
If fungi are absent there is more biologically available nitrogen and phosphorus
False
True or False
Fungi decomposition is a major component of the global carbon cycle
True
True or False
Mycorrhizae fungi give plants sugars in exchange for nitrogen and phosphorus
False
True or False
Mycorrhizae fungi help plants communicate with each other
True
True or False
Mycorrhizae fungi give plants nitrogen and phosphorus in exchange for sugars
True
What would happen to the amount of biologically available N & P if all the fungi in the forest was removed?
It would rise
What is an acoelomate?
An invertebrate lacking a coelom
What traits make sponges an animal?
Lack true tissues, collagen holds individual cells together, built around a central cavity, mostly marine filter feeders
What traits make up an invertebrate?
Lack a cranium, lack defined vertebral column/spine, live in terrestrial/aquatic environments, most have a hard outer skeleton that protects the body
What symmetry do Cnidarians have?
Radial symmetry
What are some ex amples of
