Cell Division and Growth

Question 1

what is growth?

Answer 1

an increase in size or mass

Question 2

what is cell differentiation?

Answer 2

• the process by which a cell changes to become specialised for its job
• allows multicellular organisms to work more efficiently

Question 3

what is cell division?

Answer 3

by mitosis

Question 4

what is cell elongation?

Answer 4

where a plant cell expands, making the cell bigger and making the plant grow

Question 5

why do cells divide?

Answer 5

• divide at a fast rate when young for growth
• for repair when adult, to replace old or damaged cells
• cell differentiation is lost at an early stage

Question 6

how do animals grow?

Answer 6

cell division

Question 7

how do plants grow in height?

Answer 7

• cell elongation
• cell division happens in the tips of the roots and shoots (meristems)
• grow continuously
• continue to differentiate to develop new parts (leaves, roots etc.)

Question 8

how is cancer caused?

Answer 8

• uncontrolled cell division
• a change in one of the genes that control cell division
• results in a mass of abnormal cells (tumour) which invades and destroys surrounding tissue

Question 9

what are percentile charts?

Answer 9

used to monitor growth

Question 10

what are growth charts?

Answer 10

to assess a child’s growth over time so an overall pattern in development can be seen and any problems highlighted

Question 11

what problems would be highlighted?

Answer 11

obesity
malnutrition
dwarfism

Question 12

what are baby’s measurements taken in?

Answer 12

length
mass
head circumference

Question 13

what does the 50th percentile show?

Answer 13

the mass that 50% of babies will have reached at a certain age

Question 14

how do doctors investigate a baby size?

Answer 14

• if it is above the top percentile line or below the bottom percentile line
• if their size increases or decreases by 2 or more percentile lines over time
• if there’s an inconsistent pattern