Cell division, cell diversity, cellular organisation

Question 1

Means of cell division in animals, plants, yeast, bacterium

Answer 1

-cytokinesis, cytokinesis, budding, binary fission

Question 2

Material in cell walls in animals, plants yeast and bacterium

Answer 2

-none, cellulose, chitin, peptidoglycan

Question 3

presence of ribosomes in animals, plants, yeast, bacterium

Answer 3

-all yes

Question 4

Name two types of cell that can be found in phloem tissue

Answer 4

-sieve tube elements, companion cells, parenchyma

Question 5

Cell cycle; interphase

Answer 5

• G1, cell increases in size, proteins produced, organelles replicate
• GO, some cells leave cycle, differentiated cell no longer able to divide
• synthesis, DNA in nucleus is replicated
• G2, duplicated DNA checked for errors

Question 6

Name the process of asexual reproduction in yeast.

Answer 6

-budding

Question 7

) Outline the process of asexual reproduction in yeast.

Answer 7

mitosis ;
swelling / bulge, in (surface of) the cell ;
nucleus moves into, swelling / bulge / bud ;
idea that, bulge / bud, nips / pinches / breaks off / cleaves ;
ref to uneven distribution of cytoplasm ;

Question 8

Even when the environmental conditions are perfect, one yeast cell rarely produces the
calculated number of potential new cells.
Suggest why the reproductive potential of the yeast cell is not reached

Answer 8

not enough space between scars for another bud ;
yeast cell not a true sphere ;
(gene) mutation / DNA damage

Question 9

Yeast cells separate after cell division. In a multicellular organism, the cells do not separate
but become organised to form the body structure.
Describe how the cells in a multicellular organism are organised

Answer 9

(cells) differentiate(d) / specialise(d) ; 4 max
(groups of) cells form tissue(s) ;
(groups of) tissues form organ(s) ;
(groups of organs) form organ system(s) ;
(group of) cells / tissues / organs / organ systems, work
together / interact

Question 10

stages of mitosis

Answer 10

• pmat

- prophase, metaphase, anaphase, telophase

Question 11

prophase

Answer 11

• chromosomes condense and become visible
• spindle fibres emerge from the centrosomes
• nucleur envelope breaks down
• centrosomes move towards opposite poles

Question 12

metaphase

Answer 12

-chromosomes are lined up at metaphase plate
-each sister chromatid is attached to a spindle fibre originating from opposite poles
-

Question 13

anaphase

Answer 13

• centromeres split in 2
• sister chromotids, (now called chromosomes) are pulled towards opposite poles
• certain spindle fibres begin to elongate the cell

Question 14

telophase

Answer 14

• chromosomes arrive at opposite ends and begin to decondense
• nuclear envelope material surrounds each set of chromosomes
• the mitotic spindle breaks down
• spindle fibres continue to pull poles apart