Cell Division

Question 0

Totipotent

Answer 0

A stem cell that is able to divide to form any of the specialised cells in the body

Question 1

Differentiation

Answer 1

The development if a cell to become specialised for a particular function

Question 2

What cells are totipotent

Answer 2

Any cells in a blastocyst

Question 4

Stem cell

Answer 4

undifferentiated cells
capable of becoming specialised
to a number of cell types

Question 5

Blastocyst

Answer 5

Tiny ball of cells formed by a ZYGOTE as it’s cells REPEATEDLY divide

Question 6

What is the role of mitosis

Answer 6

Repairs damaged cells
Replaces old worn out cells
asexual reproduction

Question 7

What can stem cells do dfferently from human cells

Answer 7

they are unspecialised
divide repeatedly to make new cells
differenntiate into specialsed cells

Question 8

Another name for erythrocytes

Answer 8

REd blood cells

Question 9

Describe the stages of the cell cycle

Answer 9

G1- intensive cellular synthesis, organelle production, cell mass increases
S- DNA replication, one chromosome made of 2 chromatids
G2- synthesis, centrioles replicated, cell mass increases
Mitosis- 4 stage nuclear division
Cytokinesisi- cytoplasm is distrubuted evenly betwen daughter cells

Question 10

Definition of chromosome

Answer 10

A structure made from DNA and histones found in the nucleus of eukaryotic cells

Question 11

Definition of chromatid

Answer 11

one of 2 IDENTICAL PARTS OF chromosomes
HELD BY A CENTROMERE
formed during interphase

Question 12

what is chromatin

Answer 12

structure made of DNA where the chromsomes havent condensed

Question 13

products of mitosis

Answer 13

Synthesis- DNA replication
G2- organelle production
2 genetically identical daughter cells
spindle fibres

Question 14

factors that affect viral infection

Answer 14

Inherited
Mutations
cancerous growths

Question 15

Explain why it’s important that eggs are haploid

Answer 15

Restore the haploid number at fertilisation

prevents doubling of chromosome number each generation

Question 16

definition of homologous

Answer 16

chromosomes that have the same genes at the same loci

diploid organisms produced by sexual reproduction have HOMOLOGOUS PAIRS OF CHROMOSOMES- One member of each pair from the male and the other member from the female pparent

Question 17

How are chromosomes checked for mutations

Answer 17

Proof reading enzymes, move along DNA strands and check copying has been done properly

Question 18

What are the effects in the genes are not copied precisely

Answer 18

Mutations can occur, and the new cells may fail to function

Question 19

What factors affect the rate of the cell cycle

Answer 19

Cell type
species
availability of nutrients

Question 20

Why is mitosis for such a short amount of time

Answer 20

Chromosomes can’t perform their normal functions when SUPERCOILED in the prophase, so they have to spend as little time as possible in this stage

Question 21

How many chromosomes are in a human red blood cell

Answer 21

None it has no nucleus

Question 22

Why don’t bacteria do mitosis

Answer 22

They don;t have chromosomes, centrioles or spindles of eukaryotes

Question 23

What’s the difference between plant cells and animal cells in mitosis

Answer 23

Any animal cell can do mitosis
only meristem plant cells can do mitosis

Plants don’t have centrioles, chromatids are pulled towards poles
cell wall formed at cytokinesis

Question 24

Suggest why most plant cells except meristem cells dont do mitosis

Answer 24

The formation of the cell wall in plant cells stops them from being able to divide properly

Meristem cells have a very thin cell

Question 25

3 ways in which differentiation can occur

Answer 25

Change in the number of cells
Change in the shape of cells
Change in the contents of cells