cell division

Question 1

what do chromosomes do

Answer 1

Chromosomes carry genetic information in a molecule called DNA.

Question 2

mitosis- a cell divides when

Answer 2

-an organism grows
-an organism becomes damaged and needs to produce new cells

Question 3

what are stem cells?

Answer 3

-are cells that have not undergone
differentiation

-a cell which has not yet become
specialised
is called undifferentiated.

Question 4

what happens in stem cells?

Answer 4

an embryo develops from a fertilised egg. Cells at the early stages in the development of the embryo are stem cells.

If cells are removed from the embryo – called embryonic stem cells- they will differentiate into any cell type.

Question 5

adult stem cells can be found in several regions including the :

Answer 5

brain
eyes
blood
heart
liver
bone marrow
skin
muscle

Question 6

stem cells in plants

Answer 6

Cell division in plants occurs in regions called meristem

Cells of the meristem can differentiate to produce all types of plant cells at any time
during the life of the plant.

The main meristems are close to the tip of the shoot, and the tip of the root.

Question 7

what is an advantage of plant stem cells

Answer 7

-can be used to make clones of plants quickly and cheaply
-can help endangered species close to extinction
-crops that are resistant to diseases and pests, and produce large numbers of genetically identical plants.

Question 8

what is cell differentiation?

Answer 8

Animals and plants produced by sexual reproduction begin life as a single cell

• a fertilised egg or zygote

Question 9

how is the circulatory system specialised

Answer 9

-transports substances
-defend the body, regulate temperature

Question 10

how is the muscular system specialised

Answer 10

brings about movement

Question 11

how is the nervous system specialised?

Answer 11

carry messages for the body work as a coordinated whole

Question 12

how is the reproduction system specialised

Answer 12

Bring about fertilisation to produce new offspring

Question 13

how are palisade mesophyll specialised

Answer 13

to carry out photosynthesis

Question 14

how is the xylem cell specialised

Answer 14

Transport water and dissolved minerals from the roots, up the plant

Question 15

how is the phloem cell specialised

Answer 15

Transport products of photosynthesis,

including sugars and amino acids,

Question 16

cloning in plants will be ?

Answer 16

genetically identical to the original plant
for desirable characteristics eg. disease resistant

Question 17

what are human stem cells

Answer 17

Stem cells can divide to produce new cells, which can then divide into different cell types.

. They could be used to replace cells that have been damaged or destroyed

They have to be transplanted into patients

Question 18

give examples of what human stem cells can be used for

Answer 18

in type 1
diabetes

in cases of multiple sclerosis
, which can lead to paralysis

in cases of spinal cord , brain injury, that have led to paralysis

Question 19

what stem cellls are there?

Answer 19

-embryonic stem cells
-adult stem cells

Question 20

embryonic stem cells information

Answer 20

Embryonic stem cells can differentiate into a wider range of cell types

difficult to obtain and their uses raises ethical challenges.
The best source is the five-day-old embryo.

Question 21

adult stem cells information

Answer 21

Adult stem cells will differentiate into a narrower range of cell types.

Question 22

example of adult stem cell transport

Answer 22

Bone marrow cells will differentiate into different types of blood cell

in cases of blood cell cancer
such as leukaemia and lymphoma
when blood cells have been destroyed by cancer treatment