Biology Flashcards
How many chromosomes are in the human cells, and where?
Every human body cell contains 46 chromosomes in it’s nucleus.
What is a chromosome?
A chromosome is a long length of DNA.
How many chromosomes are in sex cells?
Gametes contain 23 chromosomes each.
Why do we resemble out parents?
You resemble your parents because you inherit characteristics form them.
What are genes?
Genes make up chromosomes and code for particular characteristics.
What makes up DNA?
There are four different types of bases: A, C, T, and G.
How do the bases of DNA stick together?
A and T only fit together, and C and G only fit together, since their complementary. Bonds keep the bases stuck together.
What do the DNA bases stand for?
A - Adenine
C - Cytosine
T - Thymine
G - Guanine
What do humans, plants, and animals have in common?
We all where the same DNA.
What is variation?
When the genetic makeup of different species are different. There are 2 types of variation; continuous and discontinuous.
What is selective breeding?
An artificial process in which organisms with desired characteristics are chosen as parents for the next generation.
Why are humans different?
Humans are different because they inherit different characteristics from their parents.
What are a person’s characteristics caused by?
A person’s unique characteristics are caused by genes (nature) and the environment (nurture)
What is discontinuous variation?
Characteristics that show discontinuous variation are placed in distinct categories and:
The environment has little or no effect
It’s usually caused by 1 or 2 inherited genes
You either have the gene or you don’t.
What is continuous variation?
Continuous variation is caused by the combined effect of several genes and the environment, and cannot be easily places into individual categories.
