Part 3 - Growth Flashcards
Define the term ‘hormone’
A signalling molecule within a multicellular organism; effectively hormones deliver messages between cells
Define the term arthropod?
A phylum of the animal kingdom
They do not have a backbone (invertebrate)
They have a skeleton on the outside of the body (exoskeleton)
A segmented body with jointed legs and are symmetrical along their length
Give some examples of Arthropods
Insects (butterflies, ants etc)
Arachnids (spiders, mites, scorpions)
Chilopods (centipedes)
Diplopoda (millipedes)
What are the three processes involved with growth?
Cell division
Synthesis of new structures from raw materials
Cell expansion
What sort of growth pattern do vertebrates show?
Vertebrates tend to start with slow growth, then speed up the rate of growth before slowing down again
What sort of growth pattern do arthropods show?
Arthropods show a stepped growth pattern
What factors determine growth in plants and animals?
External factors include temperature, diet and light . Growth is determined internally by hormones
What are meristems and where are they found?
Meristems are actively dividing cells found in plants at the tip of the roots and shoots
What is secondary growth in plants?
It is the increase in girth
What does an arthropod do when it grows bigger?
It sheds
When a cell divides what are the cells called that are produced?
Progeny cells or daughter cells
What is the difference between the growth of a multicelled organism and a single celled organism?
Multicellular organisms grow in size whereas single celled organisms grow in numbers
Define the term mutation?
A change in the genes of a plant or animal that causes it to become different
What is asexual production?
Only one parent is needed to produce offspring
This is what single celled organisms do
What is sexual reproduction? The
Two parents are required to produce offspring
What is the process that most prokaryotic cells divide?
Binary fission
Reproduction of a cell by division into two approximately equal parts
The process of cell division, binary fission, in prokaryotes is much simpler than the process of cell division in eukaryotes because the cells are simpler.
In what way are prokaryotic cells simpler than eukaryotic cells?
Prokaryotic cells do not have internal organelles
What is meant by the term cell cycle?
It is a series of processes that take place in a cell
How long can a cell cycle of a eukaryote take?
Anywhere from a few hours to many weeks
What factors does the rate at which a cell proceeds through the cycle depend on?
Type of organism
The type of cell
It’s size
Environment in which it is growing