Chapter 4: Heredity & Disease Flashcards
(25 cards)
What does DNA stand for
deoxy-ribo-nucleic acid
what shape is DNA
a double helix
what is DNA made up of
- Deoxyribose sugar
- Phosphate
- Nucleotide Bases
gene
a segment of DNA that codes for a particular protein
chromosome
DNA tightly packaged with proteins
how many pairs of chromosomes in a human are autosomes
44 chromosomes (or 22 pairs)
sex chromosomes
2 chromosomes in a human.
XX is female
XY is male
karyotype
a visualization of an organisms complete set of chromosomes arranged by size
what does meiosis do?
the process of the separation of chromosome pairs
how many parts of meiosis are there
two
mutations
mistakes during replication (meiosis)
lead to abnormal chromosome numbers
cell may possibly fix itself
what makes a diploid embryo
haploid egg + haploid sperm
crossing over
an exchange of genetic material between a pair of chromosomes
ploidy
number of sets of homologous chromosomes occuring in a cell
diploid
- 2n
- 2 sets: 1 from mother, 1 from father
- somatic cells
haploid
- n
- gametes
- 1 set
alleles
alternate forms of a gene
homozygous
2 alleles of the gene are the same
heterozygous
2 alleles of the gene that are different
dominant trait
only 1 copy of an allele is needed to cause the trait
• co-dominance (AB blood)
recessive trait
2 copies of an allele needed to cause the trait (must be homozygous to appear)
genome
the complete set of DNA in an organism
hereditary diseases
defective genes make defective protein(s) OR no proteins
multifactoral traits
traits that result from the action of several genes
-environmental likely to contribute as well
