cell division

Question 1

what are chromosomes made of?

Answer 1

dna molecules ( AT, CG )

Question 2

what does each chromosome carry?

Answer 2

a large number of genes

Question 3

in normal body cells, what are the chromosomes normally found in?

Answer 3

pairs

Question 4

what are the stages of mitosis?

Answer 4

prophase, metaphase, anaphase and telophase

Question 5

what happens in stage 1?

Answer 5

cell grows bigger, dna replicates, increase number of sub-cellular structures

Question 6

what happens in stage 2?

Answer 6

complete set of chromosomes is pulled to each end of the cell, the nucleus divides into two nuclei

Question 7

what happens in stage 3?

Answer 7

cytoplasm and cell membrane divide to form two identical daughter cells

Question 8

what is a stem cell?

Answer 8

an undifferentiated cell that can develop into one or more types of specialised cells

Question 9

what are the two stem cells in mammals?

Answer 9

embryonic and adult stem cells

Question 10

where are adult stem cells found?

Answer 10

in certain body parts of adults and children eg: bone marrow

Question 11

where are embryonic stem cells found?

Answer 11

early human embryos

Question 12

where are plant meristems found?

Answer 12

the roots and the shoots of plants

Question 13

what can adult stem cells differentiate into?

Answer 13

certain types of cells, for example, bone marrow can only differentiate into types of blood cells

Question 14

what can embryonic stem cells differentiate into?

Answer 14

can differentiate into any specialised cell

Question 15

what can plant meristems differentiate into?

Answer 15

all cell types and can create clones of the whole plants

Question 16

what are the advantages of using adult stem cells?

Answer 16

fewer ethical issues ( concent ), established technique for treating disease, relatively safe to use as treatments and donors recover quickly

Question 17

what are the advantages for embryonic stem cells?

Answer 17

can treat a wide range of disease as can form any specialised cell, could replace organs, usually no donor needed`

Question 18

what are the advantages to using plant meristems?

Answer 18

rare species of plant can be cloned, plants with good traits could be cloned, fast and low-cost production

Question 19

what are the disadvantages of using adult stem cells?

Answer 19

requires a donor, can only differentiate into certain types of specialised cells

Question 20

what are the disadvantages of using embryonic stem cells?

Answer 20

ethical issues as the embryo is destroyed, rish of transferring viral infections, newer treatment so under researched

Question 21

what are the disadvantages of plant meristems?

Answer 21

cloned plants are genetically identical so a disease could destroy it easily

Question 22

what happens in therapeutic cloning?

Answer 22

cells can create a cloned early embryo, cells can be used for treatments and growing new organs, cells have the same genes as patient so are less likely to reject when transplanted