Science (DNA And Varation And Evolotion And Inhertnace ) Flashcards
What is the structure for DNA
Double helix because they are two strands of DNA
Where is DNA found
Nucleus
What are genes
Genes code for particular sequences of amino acids to make proteins
What is genome
All the genetic material in a organism
Gammet
Sex cells
What cell division produce gammets
Meiosis
What is fertilisation
When the sperm and egg mix
What is asexual reproduction
1 parent (it only take 1 to make things ) and they always genetically to there parent
What is a clone
A group of organisms that are genetically identical
Disadvantage of asexual reproduction
If they get a disease all there offspring would die
Advantage of sexual reproduction
If one gets a disease there offspring might not be affected
Advantage of asexual reproduction
Less time consuming
Disadvantage of sexual reproduction
Time consuming to find a partner
What is mitosis use for
Growth ,repair , and asexual reproduction
What is meiosis for
For gametes cell and sexual reproduction
How many pairs of chromosomes decide what sex you are
1 pair
What are males chromosome
Xy
What are female chromosomes
Xx
What are alles
the different versions of the smae gene
What are enzymes
Cells that can’t work well with each-other if the conditions around them change too much
Example of automatic control systems
Nervous system or hormones
What is homeostasis
Homeostasis is defined as a self-regulating process by which a living organism can maintain internal stability while adjusting to changing external conditions
What are respecter cells know as
Stimulus
What does the stimulus do
Detects changes in environmental (internal condition)
Example of a stimulus
The concentration of glucose in your blood
What does co ordination centre do
They receive and passes the information from the stimulus
Example of Co ordination centre
Brain , spinal cord , pancreas
What is a effector
To carry out the response and restore the optimum level
What is a example of a effector
A muscle or gland
How many time does meiosis split
Two divisions
How many times does mitosis split
One time
Order of nervous pathway
Stimulus- receptor - sensory neuron -cns-motor neurons-effector -response
Describe mitosis
2 daughter cells
The are genetically identical
Divides once
Daughter cells are the same as parent in humans 46 chromosomes
Growth and repair asexual reproduction
Describe meiosis
Four daughter cells
Daughter cells are not genetically identical
Divide twice
Chromosome reduce by half so 23
Produce gannets for sexual reproduction
Fossil could be
Remains of an organism has not decayed
Traces of organisms such as footprints and burrows
