BIO PAPER 2

What is a community?

All of the organisms living in the same habitat.

What happens when light is too bright?

• Muscles in the iris contract

• Reduce size of pupil

• Reduces (amount of) light entering

What is an advantage to genetically different produce?

Not all susceptible to the same disease / pathogen.

What is an advantage of genetically identical produce?

They grow at the same rate.

What is tissue culture?

A group of cells are grown into a new organism.

How does selective breeding work?

• Breed best of A and B (together)

• Select offspring with highest egg numbers and heaviest / fastest growing

• Breed (these) offspring together

• Repeat over many / several generations.

Why does PH of milk change more quickly when temperatures are higher?

• Enzymes more active or more bacteria produced

• Lipids broken down more quickly

• Fatty acids produced more quickly (which changes pH)

How does increased diversity of trees increase biodiversity?

• More / different types of food available

• More / different types of habitat shelter or nest sites available

Why can reduced FSH cause underdeveloped breasts?

• Lack of FSH causes lack of oestrogen (production)

• Breast development is dependent on oestrogen

Why are cells produced from Meiosis genetically different?

• Random chromosome from each pair (of chromosomes)

• Moves to one end of the cell

How did fossils help make Darwin’s theory of evolution accepted?

• They show change over time

• Fossil records shows development of species over time

• They show evidence of extinction