reproduction and inheritnce Flashcards
what is a mutation?
a change in the DNA of a cell
What is a chromosome?
a single DNA molecule coiled around proteins called histones, allows the DNA to be packed and protected
what is a gene?
a short length of DNA that codes for a single protein
what are alleles?
different versions of the same gene
define “dominant”
allele of a gene that is expressed in the same heterozygote
define “homozygous”
genotype with the same alleles of a gene
define “recessive”
alleles that is not expressed in the phenotype when a dominant allele of the gene is present
define meiosis
cell division to produce gametes, it produces 4 haploid cells whose chromosomes are NOT identical
describe the process of metaphase
a structure called “spindle” forms
- the chromosomes line up at “equator” of spindle, attached to it by their centromeres
describe the process of prophase
- before mitosis DNA duplicates a cell that hasn’t started dividing, has a clear nucleus surrounded
-duplicated chromosomes begin to condense and become invisible - a spindle starts to form in cytoplasm
what is DNA?
MOLECULE THAT STORES GENETIC INORMATION IN THE FORM OF A CODE
DEFINE “HETEROZYGOUS”
a genotype with different alleles of a gene
define “genotype”
alleles an organism for a certain characteristic
define “phenotype”
how a gene is expressed, the “appearance” of an organism resulting from it’s genotype
define “codominance”
pattern of inheritance where neither allele of a gene is dominant over the other so that both alleles are expressed in the phenotype
