Which of the following distinguishes the prophase1 of meiosis from the prophase of mitosis?
1. homologous chromosomes pair up
2. spindle forms
3. nuclear membrane breaks down
4. chromosomes become visible

Identify the structure of the amino acid that is a Zwitter ion :

The ion required as the co-factor for the proteolytic enzyme, carboxypeptidase, is:
1. Zinc

2. Copper

3. Iron

4. Manganese

With respect to meiosis, when does DNA replication occur?
1. Before meiosis I only
2. After meiosis I only
3. Before and after meiosis I
4. After meiosis II

The inhibition of succinic dehydrogenase by malonate is an example of:
1. Non-competitive reversible inhibition
2. Non-competitive irreversible inhibition
3. Competitive inhibition
4. Allosteric inhibition

The component molecules of the cell membrane have two main parts, the head and the tail. These parts are either hydrophobic (repelled by water) or hydrophilic (attracted to water). Which is which?
1. Hydrophilic Head and Hydrophobic Tail
2. Both Hydrophobic
3. Hydrophilic Tail and Hydrophobic Head
4. Both Hydrophilic

The living state of an organism is a :
1. non-equlibrium steady state
2. non-equilibrium variable state
3. steady state in perfect equlibrium
4. variable state in perfect quilibrium

The main difference between active transport and facilitated diffusion is:
1. In active transport the molecules move from areas of high to areas of low concentration
2. In active transport, you need carrier proteins
3. In active transport you need ATP to move molecules against a concentration gradient
4. In active transport, only water molecules move.

Scientists think that mitochondria may have once been separate living organisms for all of the following reasons except that they
1. have cilia and flagella
2. have their own DNA
3. can reproduce
4. can produce their own proteins

The phase of mitosis in which the spindle fibers break apart, two new nuclear membranes begin to form, and the chromosomes disperse into chromatin is
1. metaphase
2. telophase
3. anaphase
4. prophase