Section 1 - The Nature and Variety of Organisms P2

Question 1

What are specialised cells?

Answer 1

Cells which are designed to carry out a certain function

Question 2

How is red blood cell adapted?

Answer 2

Has a dip so it has a bigger surface to diffuse more oxygen and doesn’t have a nucleus so there’s more space to carry oxygen

Question 3

How can you investigate how pH affects Enzyme activity?

Answer 3

ADD A BUFFER SOLUTION WITH A DIFFERENT pH LEVEL OF THE TUBES CONTAINING THE ENZYME-SUBSTRATE SOLUTION

• You can use the enzyme catalyse which catalyses the breakdown of hydrogen peroxide into water and oxygen
• collect the oxygen in a measuring cylinder and measure how much is given off over a certain amount of time
• run a series of experiments with different temperature water baths at different temperatures to see how temperature affects the reaction
• control variables-enzyme concentration,volume of solution

Question 4

What are specialised cells?

Answer 4

Cells that are designed to carry out a particular function

• their structures can vary
• most cells are specialised to a degree

Question 5

What are examples of human specialised blood cells?

Answer 5

• read blood cells- specialised for carrying oxygen

- white blood cells- specialised for defending the body from pathogens

Question 6

What is cell differentiation?

Answer 6

The process by which a cell changes to become specialised for its job

Question 7

What ways can a cell change?

Answer 7

• can develop different organelles

- turn into different types of cells

Question 8

What are undifferentiated cells called?

Answer 8

Stem cells

Question 9

What is the importance of stem cells?

Answer 9

-can divide and produce lots more undifferentiated cells, and then can differentiate into different types of cells depending on what instructions they are given

Question 10

Where are stem cells found?

Answer 10

In early human embryos

Question 11

Why are stem cells interesting to doctors and medical researchers?

Answer 11

-they have the potential to turn into any kind of cell at all

Question 12

Where are stem cells found in adults?

Answer 12

Only in certain places, such as bone marrow

-unlike embryonic cells they can’t turn into any cell type at all, only certain ones, such as blood cells

Question 13

What have stem cells from embryos and bone marrow been used to grow in labs?

Answer 13

• clones (genetically identical cells)

- made to differentiate into specialised cells to use in medicine or research

Question 14

How can stem cells cure many diseases?

Answer 14

• medicine already uses adult stem cells to cure disease
• embryonic stem cells could also be used to replace faulty cells in sick people (make insulin producing cells for people with diabetes, nerve cells for people paralysed by spinal injuries…)

Question 15

What are the risks involved with using stem cells in medicine?

Answer 15

-Stem cells in labs may become contaminated with a virus which could be passed on to the patient, making them sicker

Question 16

Why are people against stem cell research?

Answer 16

• human embryos shouldn’t be used for experiments since each one is a potential human life
• campaigners think scientists should work on finding and developing other sources of stem cells

Question 17

What are arguments for stem cell research?

Answer 17

• curing existing patients who are suffering, in some peoples opinion is more important than rights of embryos
• embryos used in research would be unwanted ones from fertility clinics (which would probably be destroyed otherwise)