Chapter 2 - From Conception to Birth Flashcards
Deoxyribonucleic Acid (DNA)
Chemical composition of the molecules that contain the genes
Genes are the chemical instructions for cells to manufacture proteins
Chromosome
Molecules that come in 23 pairs (46 total) that contain the entirety of a human’s genes
Zygote
A single cell created by combining two gametes (sex cells)
A fertilized ovum (egg)
Homozygous
Two genes of one pair that are exactly the same in every letter of their code
Vast majority of human genome are identical to one another
Heterozygous
Two genes of one pair that differ
Allele
A variation that makes a gene different in some way; an expected mutation of the reproductive process
Genotype
The collection of an organism’s genes
Phenotype
The collection of EXPRESSED genes; actual physical characteristics
True of false: due to our genetic diversity, humanity as whole has greater survivability against deadly diseases
True. The genetic diversity in humans means that there is a great chance that there is a subset of the population that is resistant or unaffected by a disease
An example of this is how some people have genes that make them less susceptible to HIV/AIDS than others
Genome
The full set of genes to make an individual member of a certain species
Any two human beings share what percentage of their genes with another, no matter the race/ethnicity/etc.?
At least 99.5% of genetic code is shared between any two humans
Monozygotic twins
Twins who originate from a single zygote that splits apart very early in development
Identical twins that have virtually identical genetic instructions
Dizygotic twins
Also known as fraternal twins, they originate from two SEPARATE zygotes
Caused by the female ovulating two ova
Additive genes
Genes who’s effects ‘add up’ to result in a phenotype (expressed physical trait)
Germinal period
The first two weeks of development of a zygote
Rapid cell division and the beginning of cell differentiation
