01Heredity/Genotype & Phenotype

nature

refers to the contribution of genetics to one's development

genes

basic building block of the nature perspective

genes

specific sequence of nucleotides and are recipes for making proteins

protein

responsible for influencing the structure and functions of cells

genes

located on the chromosome

20,500

no. of estimated genes for humans

46 chromosomes (23 pairs)

no. of chromosomes that normal human cells contain in the nucleus of cells

one from each parent

there are 23 pairs of chromosomes, from who?

mitosis

process that takes place after conception, which is where most cells of the body are created

mitosis

cell's nucleus making an exact copy of all the chromosomes and splitting into 2 new cells

gametes

cells used in sexual reproduction

ova / sperm

gametes < (2/)

meiosis

gametes are formed in this process

gametes

are formed in the process of meiosis

meiosis

gamete's chromosomes duplicate, and then divide twice resulting in 4 cells containing only half the genetic material of the original gamete

meiosis

results in a cell that has 46 chromosomes from 23 in sperm and 23 in egg

genes

basic physical functional unit of heredity

autosomes

22 of the 23 pairs of chromosomes

autosomes

chromosomes that are similar in length

sex chromosomes

chromosomes that differ in length

sex chromosomes

1 of the 23 pairs of chromosomes

genotype

refers to the sum total of all the genes a person inherits

phenotype

features from genes/chromosome that are actually expressed

homozygous

receiving the same version of a gene from BOTH mother and father

heterozygous

receiving different version of a gene from BOTH mother and father

homozygous

it is sure that the phenotype is that characteristic

heterozygous

not all genes are created equal, so there may be times one is expressed while the other characteristic isn't

dominant / recessive

heterozygous: inequality in genes < (2/)

dominant

heterozygous:

express themselves in the phenotype even when paired with a different version of the gene

recessive

heterozygous:

express themselves only when paired with a similar version gene

alleles

different versions of a gene

polygenic

characteristics that are a result of several genes

incomplete dominance

when the dominant gene doesn't completely suppress the recessive gene

carriers

people who have inherited only one recessive-gene

carriers

these people SHOULD be unaffected by the recessive trait they inherited

monozygotic

this occurs when a fertilized egg splits apart in the first 2 weeks of development

dizygotic

this occurs when 2 eggs/ova are released and fertilized by 2 separate sperms

identical twins

monozygotic AKA

fraternal twins

dizygotic AKA

monozygotic

creation of 2 separate, but genetically identical offspring

monozygotic

twins that possess the same genotype, and often the same phenotype

dizygotic

twins that share the same amount of genetic material as would any 2 children form the same mother and father

dizygotic

twins that possess different genotype and phenotype