DNA, genes, mutations, chromosomes Flashcards
chromosomes
threadlike structures made mostly of DNA
where are chromosomes found?
in the nucleus
DNA
material containing genetic information
where is DNA found?
in the nucleus
gene
segment of DNA controlling protein production
what does the nucleus contain?
instructions that determine what each cell will become, how it will function, and how long it will live before being replaced
every plant/animal species has a ______ in the nucleus of each cell
specific number of chromosomes
humans contain ____ chromosomes (__ pairs)
46 / 23
what are chromosomes made of?
DNA
what does DNA stand for?
deoxyribonucleic acid
every chromosome consists of a single molecule of ____ which is divided into segments called _____
DNA / genes
what controls the cell’s activities and how?
genes / controlling what proteins are made and when
what are the 4 types of nitrogen bases?
adenine (a)
thymine (t)
cytosine (c)
guanine (g)
which nitrogen bases pair together?
a + t (apple in the tree)
c + g (car in the garage)
what is genetic code?
the order in which nitrogen bases are strung together
genetic code determines _________
the kind of proteins your cells can make, and therefore how your body might function or look
why is DNA important?
it controls many physical features (ex. hair/eye colour) and whether you can digest certain foods (ex. milk)
= it makes each person unique
DNA provides directions that __________
guide the repair of worn cell parts and the construction of new ones
in each pair of chromosomes, one comes from ____ and the other from _____
your mother / your father
what is the ladder shape of DNA called?
the double helix
DNA is able to ______
make a perfect copy of itself
why is DNA duplication important?
it is needed for mitosis and meiosis
mutation
a change in the DNA of an organism
what is the effect of a mutation?
alters structure of protein it produces or how well the protein does its job
mutagen
a substance/factor that can cause a mutation in DNA
DNA screening
the process of testing individuals to determine whether they have gene(s) associated with certain genetic disorders
what human specimen does not have 46 chromosomes?
egg
sperm
what molecules make up the “ladder” of DNA?
phosphate
deoxyribose
what molecules make the “rung” of DNA?
nitrogen bases
what do genes control?
cell activities, cell structure, protein production
what are 2 ways a mutation might not be harmful?
if it occurs in a nongenetic part of DNA
if it is neutral (does not affect DNA)
what is a nucleotide?
basic “building block”
what is a nucleotide made of?
sugar (deoxyribose)
phosphate
nitrogenous base
diploid cell
a human body cell that contains 23 homologous pairs of chromosomes
haploid cell
a human sex cell that contains 23 chromosomes
