topic 4 cards Flashcards
what are some examples of human characteristics
hair: curly straight Dimples: yes or no Toe: short 2nd toe or long 2nd
what are some examples of continuous characteristics
skin tone, height
what are some examples of characteristics that are discrete
rolling tongue
are brown eyes dominant
yes they are the most dominant type of eye colour ex B= gene for brown eyes, b= gene for blue eyes. if you have BB Bb you will have brown eyes.
how are characteristics not all inherited
some depend entirely upon the environment ex, starts and some characteristics like weight are a combination of genetics (nature), diet and activity Level (nurture)
What can our DNA be changed by?
factor in the environment (mutagens) such as X-rays, Uv rays, cosmic rays, and chemicals in the environment such as pollutants
what can mutations cause
can cause cancer, the mutant cells divide rapidly and can interfere with normal functions
How can Mutation cause greater variation within species?
if the mutation are in the DNA of the gametes they can be passed on from one parent to child. These changes increase the variation in a species
can mutations be harmful?
mutations are usually harmful, but sometimes they can be harmless or even beneficial.
what can cause mutagens
X rays, Uv rays and chemicals in there environment
how does our body fight with mutagens
the cell indicated that it has been affected and it kills its self to create a new healthier cell humans go through this process millions and millions times a day
what are the four forms of nitrogen bases that structure the DNA
adenine (A) Thymine (T) Guanine (G) cytosine (C)
what is the (sugar base) coil that wraps around the nitrogen base made of
phosphate sugar
what does the genetic code do?
this code is like a blueprint that controls the production of proteins of the cells and tissues in plants and animals
how many chromosomes are in a human body cell
46 chromosomes
what is mitosis how does it look like?
how does the drawing look for meiosis
