B2 - cell division fact test

Question 1

what is cell division used for

Answer 1

repair and replacement of cells

Question 2

what is differentiation

Answer 2

the process where unspecialised cells become specialised

Question 3

when do animal cells differentiate

Answer 3

during early stages

Question 4

when do plant cells differentiate

Answer 4

multiple times throughout its lifetime

Question 5

what are chromosomes

Answer 5

made of DNA molecules and carry a large number of genes. they are found in the nucleus

Question 6

how many chromosomes are found in the body

Answer 6

46 (23 pairs)

Question 7

what is the division of cells known as

Answer 7

the cell cycle

Question 8

what happens during each stage of the cell cycle

Answer 8

1. increase in sub-cellular structures and DNA replicates to form 2 copies of each chromosome
2. mitosis - one set of chromosomes are moved to opposite ends of the cell and the nucleus divides
3. the cytoplasm and cell membrane divides to form 2 GENETICALLY identical daughter cells

Question 9

what are stem cells

Answer 9

undifferentiated cells which can produce specialised cells and more stem cells

Question 10

where are stem cells found in humans

Answer 10

embryos and bone marrow

Question 11

where are stem cells found in plants

Answer 11

meristem tissue

Question 12

how are stem cells from embryos used

Answer 12

can be cloned and made to differentiate into most different types of human cells

Question 13

how are stem cells from bone marrow used

Answer 13

can differentiate into many different types of blood cells

Question 14

how are stem cells from meristem tissue used

Answer 14

can differentiate into any type of plant cell, throughout its lifetime

Question 15

what medical conditions are stem cells used to treat

Answer 15

type 1 diabetes and paralysis

Question 16

what is therapeutic cloning

Answer 16

where an embryo is produced with the same genes as the patient. this means the stem cells from the embryo are not rejected by the patient’s body and can be used in treatment

Question 17

what are the disadvantages of using stem cells

Answer 17

• potential risks such as transfer of viral infection
• ethical and religious objections as an embryo can be considered a life

Question 18

what are the advantages of meristem tissue in plants

Answer 18

• can produce clones of plants quickly and economically
• rare species can be cloned to protect them from extinction
• crop plants with special features such as disease resistance can be cloned to produce large numbers of identical plants for farmers