Multicellular Organisms Flashcards
Describe the sequence of mitosis?
1) chromosomes become visible
2) chromosomes line up at the equator of the cell
3) spindle fibres form and attach onto the chromosomes
4) spindle fibres contract and the pairs of chromatids are pulled apart
5) chromosomes move to the poles (opposite ends) of the cell
6) nuclear membrane reform creating 2 nuclei
7) cytoplasm divides resulting in the production of two daughter cells
What does mitosis provide new cells for?
- growth
- repair of damaged tissues
- replacement of dead/damaged cells
What is the chromosome compliment in humans?
46
What are stem cells?
Animals cells that are unspecialised cells which divide in order to self renew
What do stem cells have the potential to do?
Become different types of cells
What are stem cells involved in?
Growth and repair
Where can stem cells be obtained?
From the embryo at a very early stage of development
What do specialised cells lead to the formation of?
Variety of cells, tissues and organs
What are tissues?
Groups of speacilised cells that are similar in structure and carry out a similar function
What are organs?
Made up of many different types of tissue, containing different types of cell, which are specialised for their function. Each organism performs a different function
What are systems?
Groups of organs which work together to form systems
What does the central nervous system contain?
The brain and spinal cord
What does the cerebrum do?
Where is it on the brain?
Stores memory
Top back of the brain
What does the medulla do?
Where is it on the brain?
Controls involuntary actions (heart beat)
Bottom front of the brain
What does the cerebellum do?
Where is it on the brain?
Controls balance and coordination
Bottom back of the brain
What are the three types of neurons?
- sensory
- inter
- motor
What type of messages do neurons carry?
Electrical
What do receptors do (neurons)?
Detect sensory input/stimuli
What type of transfer carries a message between the neurons at the synapses?
Chemical
What gland releases hormones into the blood stream?
Endocrine gland
What type of messengers are hormones?
Chemical
Why does only he target tissue get affected by the specific hormone?
The target tissue has complementary receptors proteins for the specific hormone
What is the blood glucose regulation if blood glucose increases?
1) change is detected in the pancreas
2) pancreas releases more insulin into the blood
3) liver cells store glucose from the blood a glycogen
4) decrease in blood glucose
What is the blood glucose regulation if there is a decrease in blood glucose?
1) change detected in the pancreas
2) pancreas releases more glucagon into the blood
3) liver cells breakdown glycogen into glucose, which is released into the blood
4) increase in blood glucose
What cell is a diploid?
All cells, except gametes
What do diploid cells contain?
Two matching sets of chromosomes
What are gametes?
- sex cells
- haploid cells
What do haploid cells contain?
One set of chromosomes
What is the male animal gamete and where is it produced?
Sperm, produced in the testes
What is the female animal gamete and where is it produced?
Egg, produced in the ovaries
What is the male plant gamete and where is it produced?
Pollen, produced in the anther
What is the female plant gamete and where is it produced?
Ovule, produced by the ovary