Growth in Organisms Flashcards
All 13 cards in this deck
Which two processes bring about growth in animals?
Cell division (by mitosis) and differentiation.
Which three processes bring about growth in plants?
Cell division (by mitosis), cell elongation and differentiation.
Give three ways, other than measuring change in length, of showing the growth of seedlings.
Measure the change in mass; look at the number/size of leaves; measure the width of the seedling.
What is cell differentiation?
The process by which a cell becomes specialised to carry out a particular function.
Why is differentiation important in the development of an organism?
It produces specialised cells, so the organism has tissues and organs suited to carrying out particular functions efficiently.
What is formed when a group of similar specialised cells work together?
A tissue.
True or false? Differentiation increases the number of cells in an organism.
False. Differentiation makes cells specialised; cell division increases the number of cells.
What does it mean if a child's height is on the 25th percentile for their age?
25% of children of that age are shorter than them (75% are taller).
True or false? A child whose mass is on the 9th percentile must be growing abnormally.
False. A child can be healthy on any percentile, as long as their growth stays on or around the same percentile as they get older.
Which measurements of a child does a doctor plot on percentile charts to monitor growth?
Height, mass (weight) and head circumference, compared with other children of the same age.
What is growth?
An increase in size or mass.
What is cell elongation in plants?
A plant cell expanding to become larger. It is the main way a plant grows in height.
True or false? Most animal cells keep the ability to differentiate throughout life.
False. In most animals, cells lose the ability to differentiate at an early stage; in adults, cell division is mainly for repairing and replacing cells.