B3f-growth And Development Flashcards
What is the function of the vacuole?
Contains cell sap
Provides support
What is the function of the cell wall?
Made of cellulose
Provides support
What is the difference between bacterial and plant and animal cells?
Bacterial cells lack
A true nucleus
Mitochondria
Chloroplasts
Whats the difference in dna of bacterial cell and plant/animal cell?
Bacteria has
No nucleus
Single circular strand of dna
What are the five main phases of growth?
Infancy Childhood Adolescence Maturity/adulthood Old age
Describe infancy
Just after birth
Roughly the first two years
Rapid growth
Describe childhood
Period between infancy and puberty
Steady growth
Describe adolescence
Begins with puberty and continues until body development and growth are complete
Rapid growth
Describe maturity/adulthood
Period between adolescence and old age
Growth stops
Describe old age
65 - death
How do you measure using length?
Measure length/ height of a plant or animal
What are the advantages and disadvantages of measuring growth by length?
Advantage:
Easy to measure
Disadvantage:
Doesn’t tell you about changes in width, diameter, number of branches, etc
How do you measure growth by wet mass?
Weigh the plant or animal
What are the advantages and disadvantages of using wet mass?
Its very changeable
Animal would be heavier if they had just eaten
How do you measure using dry mass?
Dry out the organism before weighing it
What are the advantages and disadvantages of using dry mass?
Advantage:
Not affected by the amount of water in plant or animal
Disadvantage:
You have to kill the organism
What is differentiation?
The process of cells becoming specialised
What can undifferentiated stem cells develop into?
Cells , tissues and organs
What can stem cells be obtained from?
Embryonic tissue Bone marrow(adult stem cells)
Whats the difference between adult and embryonic stem cells?
Adult stem cells arent as versatile
Why are some people agains stem cell research?
Embryos could be a potential human life
Others say that the embryos are donated and would otherwise be thrown away
How do plants and animals grow differently?
- animals grow til they reach a finite size then stop
- plants grow continously
- in animals, growth happens by cell division
- in plants, cell division is restricted to areas called meristems
- plants retain the ability to differentiate
