B2 - cell division

Question 1

what is a moral disadvantage of embryonic stem cells

Answer 1

they come from IVF babies and aborted embryos which people feel is immoral

Question 2

what are adult stem cells?

Answer 2

stem cells found in adults that can only differentiate into limited numbers of cells

Question 3

are adult stem cells pluri or multi potent

Answer 3

multipotent

Question 4

what are embryonic stem cells?

Answer 4

stem cells found in embryos that can differentiate into any type of cell

Question 5

are embryonic stem cells pluri or multi potent

Answer 5

pluripotent

Question 6

what are stem cells

Answer 6

an undifferentiated cell able to undergo mitosis to make other stem cells or differentiate to become specialised cells

Question 7

what is an advantage of adult stem cells

Answer 7

tissues created won’t be rejected

Question 8

whats a disadvantage of embryonic stem cells

Answer 8

rapid cell division could cause cancer

Question 9

what is therapeutic cloning

Answer 9

a process where an embryo is produced that is genetically identical to the patient so the cells can be used in medical treatment

Question 10

what is an advantage of therapeutic cloning

Answer 10

can grow organs with no rejection issue

Question 11

what is a disadvantage of therapeutic cloning

Answer 11

the morality of the procedure is questioned

Question 12

what are some potential sources of stem cells (5 options)

Answer 12

unused embryos, bone marrow, cloned adult stem cells, umbilical chords, amniotic fluid

Question 13

what are dangers of stem cell treatment (3 options)

Answer 13

rapid cell growth could lead to cancer, stem cells from others could be rejected, new tissue could carry a virus which could attack the body

Question 14

what is differentiation

Answer 14

the process where cells become specialised for a particular function

Question 15

what does multipotent mean

Answer 15

can only differentiate into certain numbers of cells depending on where they are found e.g. adult stem cells

Question 16

what does pluripotent mean

Answer 16

a cell can differentiate into anything e.g. plant and embryonic stem cells

Question 17

how does most plant growth occur

Answer 17

cell elongation where cells swell with water and expand

Question 18

where does growth and cell division occur in plants

Answer 18

in the meristem

Question 19

where in the plant contains undifferentiated cells

Answer 19

the meristem

Question 20

when do plant cells usually differentiate

Answer 20

when they are in their final position

Question 21

can plant cells re-differentiate

Answer 21

yes they can re-differentiate and become another type of cell

Question 22

what is a nucleus

Answer 22

an organelle in the cell which contains the genetic information and controls the cells activities

Question 23

what is a chromosome

Answer 23

how the genetic material is found in the cell and is the DNA molecule coiled up into X structures

Question 24

what is DNA

Answer 24

molecules that contain the genetic instructions for the features of an organism

Question 25

what is a gene

Answer 25

a section of the DNA that codes for a particular protein, which gives a particular feature

Question 26

how many chromosomes are in human body cells

Answer 26

46

Question 27

how many chromosomes are in human gametes

Answer 27

23

Question 28

why are chromosomes found in pairs in body cells

Answer 28

because you receive 23 from your mother and 23 from your father and these form pairs

Question 29

what is a zygote

Answer 29

the new cell formed by the fusion of gametes in sexual reproduction

Question 30

how are human zygotes formed

Answer 30

the gametes (sperm and egg) combine and the chromosomes combine leaving 46 chromosomes forming a single cell with the full genetic info

Question 31

what needs to happen for a zygote to form a fully grown organism

Answer 31

cell division needs to occur in order for the organism to grow

Question 32

what is the type of cell division responsible for growth and repair

Answer 32

mitosis

Question 33

what type of reproduction is cell division

Answer 33

asexual reproduction

Question 34

what does mitosis produce

Answer 34

two cells identical to each other and the parent cell

Question 35

what is the first stage of the cell cycle

Answer 35

interphase

Question 36

what is the second phase of the cell cycle

Answer 36

mitosis

Question 37

what is the final phase of the cell cycle

Answer 37

cytokinesis

Question 38

what happens in the interphase

Answer 38

replicates DNA to form two copies of each chromosome ready for cell division and increase of number of ribosomes and mitochondria to supply enough protein and energy for cell division

Question 39

what happens during mitosis

Answer 39

chromosomes shorten and become visible as chromatids, the nuclear membrane disappears and the chromosomes line up at the middle of the cell, the chromosomes are pulled apart to opposite sides by spindle fibers

Question 40

what happens during cytokinesis

Answer 40

the nuclear membrane forms around each group of chromatids and the cytoplasm divides, the cell membrane reforms leaving two identical daughter cells

Question 41

what is a chromatid

Answer 41

half a duplicated chromosome

Question 42

why is interphase the longest stage of the cell cycle

Answer 42

the cell needs to grow and make sure the DNA has replicated before it divides as incorrect DNA causes mutations which causes cancer and needs to make sure there's enough mitochondria and ribosomes

Question 43

what is the cell cycle

Answer 43

the three stage process of cell division involving mitosis that results in the formation of two identical daughter cells

Question 44

what is cloning

Answer 44

the production of genetically identical offspring by asexual reproduction