St Peter the Apostle High School
BIOLOGY DEPARTMENT
CELL DIFFERENTIATION HOMEWORK
NAME: ________________
TEACHER COMMENT:
PUPIL COMMENT:
PARENT COMMENT:
HOMEWORK 1
1. Which of the following is not a use of stem cells?
A Skin grafts
B Drug testing
C IVF treatment
D Bone marrow transplant
(1)
2. Which line in the table below describes correctly cell division in a specific
cell type?
3. The diagram below shows some stages in the development of blood cells
and nerve cells.
(1)
(a) What are stem cells?
(1)
(b) State the location of the tissue stem cells which develop into blood cells.
(c) Describe what is meant by the term differentiation.
(1)
(1)
(d) Both embryonic stem cells and tissue stem cells are used in medical
research. Give one reason why embryonic stem cells are potentially more useful
than tissue stem cells.
(1)
4. The human body contains hundreds of cell types all of which have
developed from stem cells in the early embryo.
(a) Name two types of cell that may develop from tissue stem cells in red
bone marrow.
1.
2.
(1)
(b) (i) What type of cell division only occurs in germline cells?
(1)
(ii) Suggest why mutations in germline cells could have serious consequences.
(1)
(c) A company has developed a drug that could treat the symptoms of an
inherited disease. Before proceeding to clinical trials using volunteers, the
company decides to carry out additional tests in the laboratory using stem cells.
What ethical considerations might have influenced this decision to use stem
cells?
(2)
5.
A scientist is working on a stem cell line and is investigating the
necessary growth conditions needed to make the stem cells
differentiate into blood cells.
The cultures were set up on day 0. The scientist took the original
flask of cells, counted the cell number and made sure each of the
new flasks received the same cell number (as shown below).
Original flask of cells
Flask 1
Flask 2
with 4 × 10 5 cells
with 4 × 10 5 cells
per cm 3
per cm 3
a) The scientist performed a five-fold dilution of the cells before
transferring them into flasks 1 and 2.
How many cells per cm 3 were in the original flask if the original flask
contained 20 cm 3 of growth media?
__________ cells per cm 3
b)
After 6 days of collecting results the scientist analysed the
data, which is shown in the table below. (Note: Viable just means
the cells that are alive).
Flask 1 – media
only
Flask 2 – media +
cytokine
Viable cell number
× 10 5 per cm 3
Viable cell number
× 10 5 per cm 3
Day result
collected
0
4.0
4.0
2
4.6
4.6
4
5.0
9.2
6
3.3
10.7
8
2.1
13.8
10
1.2
27.6
12
0.3
32.9
i)
Use this data to plot a graph of the results of this experiment
ii)
What conclusion can you draw from these results?
b) Why did the scientist put the same cell number into flasks 1 and 2?
(3)
(1)
(1)
HOMEWORK 2
1. Give an account of cell differentiation under the following headings.
(i) Stem cells; (4)
(ii) Somatic cells; (4)
(iii) Germline cells. (2)