reproduction Flashcards
allele
an alternative version of a gene
chromosome
a long molecule of DNA found in the nucleus of cells
dominant
allele that only needs one copy to be expressed
fertilisation
the fusion of male and female gametes during sexual reproduction
gamete
a sex cell, e.g. and egg cell or a sperm cell
gene
part of a chromosome that codes for a protein - some characteristics are controlled by a single gene but most are controlled by genes mixing interacting
genotype
combination of alleles an individual has
heterozygous
when an individual carries two different alleles for a trait
homozygous
when an individual carries two copies of the same allele for a trait
meiosis
a type of cell division where a cell divides twice to to produce four genetically different gametes - occurs in the reproductive organs
mitosis
a type of cell division where a cell reproduces itself by splitting to form two identical offspring
phenotype
physical expression of the genotype - the characteristic shown
recessive
allele that needs two copies present to be expressed
cystic fibrosis
an inherited disorder of the cell membranes caused by a recessive allele
DNA
deoxyribonucleic acid - the molecule in cells that stores genetic information
double helix
the structure of DNA
expression
the appearance in a phenotype of a characteristic or effect attributed to a particular gene
gene
a short section of DNA, found on a chromosome, which contains the instructions needed to make a protein
genetic cross
when the offspring that might result from two known parents is considered
genome
all the genetic material in an organism
nucleotide
a repeating unit in DNA and RNA that consists of a sugar, a phosphate group and a base
polydactyly
an inherited disorder, caused by a dominant allele, where a person has extra fingers or toes
polymer
a long chain molecule that is formed by joining lots of smaller molecules (monomers) together
punnett square
a type of genetic diagram
