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

The most important significance of meiosis is that:
1. It increases variations in the gene pool of the species that helps in evolution of that species.
2. It causes growth in the multicellular organisms
3. It conserves specific number of chromosomes in each species across generations
4. It is vital for repair and regeneration functions in the living organisms.

Consider the following statements regarding meiosis:
I. At metaphase I the microtubules from the opposite poles of the spindle attach to the pair of homologous chromosomes.
II. At anaphase I, the homologous chromosomes separate, while sister chromatids remain associates with each other.
Of the two statements:

1. Only I is correct
2. Only II is correct
3. Both I and II are correct
4. Both I and II are incorrect

During meiosis, the bivalent chromosomes clearly appear as tetrads first at:
1. Zygotene of prophase I
2. Pachytene of Prophase I
3. Metaphase I
4. Anaphase I

Consider the following key events:
I. Chromosomes cluster at opposite spindle poles and their identity is lost as discrete elements.
II. Nucleolus, golgi complex and ER reform
The stage of mitosis characterized by these key events is:

1. Prophase

2. Metaphase

3. Anaphase

4. Telophase

During diakinesis of prophase I:
I. Terminalisation of chiasmata takes place
II. Meiotic spindle is assembled.
III. Nucleolus disappears and the nuclear membrane breaks down.
The correct statements are:

1. I, II and III

2. I and II only

3. I and III only

4. II and III only

Identify the correct statement regarding meiosis amongst the following:
I. Meiosis involves two sequential cycles of nuclear and cell divisions but only a single cycle of DNA replication.
II. Meiosis II is initiated after the parental chromosomes have replicated to produce identical sister chromatids at the S phase
III. Meiosis involves pairing of bivalents and recombinations between them.

1. I only

2. I and II only

3. I and III only

4. I, II and III

The enzymes that catalyse removal of groups from substrates by mechanisms other than hydrolysis leaving double bonds are called as:
1. Oxidoreductases

2. Hydrolases

3. Ligases

4. Lyases