Est: Genetics Flashcards
What are genetics?
factors responsible for characteristic traits in organisms.
what is a characteristic trait?
physical or psychological attributes that may vary from one individual to another within the same species.
what is chromatin
a mass of dna and proteins within the nucleus of most cells not undergoing mitosis.
what are chromosomes
structures that are formed when a chromatin contracts before mitosis
what are homologous chromosomes
a paired set of similar chromosomes
in humans 46 chromosomes form…
23 pairs of homologous chromosomes (one from each parent)
what is a karotype
is an ordered representation or an individual’s chromosomes, obtained by grouping them into homologous chromosomes.
what are sex chromosomes
23rd pair of a different sized chromosomes
what is the female sex chromosome
xx
what is the male sex chromosome
xy
what does a dna look like
double helix, twisted ladder shape
what does dna contain
nucleotides
what does each nucleotide contain
-a sugar: deoxyribose
-a phosphate
-one of 4 nitrogenous bases: adenine, thymine, guanine, cytosine
describe the pairing of nitrogenous based
-always pair A with T: A+T T+A
-always pair C with G: C+G G+C
What is a gene?
a segment of DNA containing the instructions to make proteins.
What creates a gene?
a particular sequence of bases (ATGC).
What is a genome?
all of the genes we receive from our parents put together.
What do genes provide?
the information for making proteins which determine our traits
What is a protein?
a molecule that plays a specific role in the functioning of an organism and in the expression of its characteristic traits.
how many proteins exist?
100 000 different proteins exists, each playing a very specific role in the organism
What are proteins composed of?
chains of Amino Acids (21 in all)
What determines the function of the protein?
The sequence of Amino Acids
What is protein made by? Where are they located?
Protein is made by Ribosomes which are located outside the nucleus.
What cannot leave the nucleus?
DNA
Because DNA cannot leave the nucleus, DNA must be…
And this is called the…
copied and carried out to the ribosome to synthesize proteins.
this is called the use of Messenger RNA
(mRNA)