Human Growth and Development - Chapter 2 (Part 1)
how much chromosomes does the human body have?
23 pairs (46 chromosomes)
Similarity between humans and every other mammal:
90%
Similarity between humans and chimpanzees
98%
Similarity between two people:
99.5%
x-linked
a gene carried on the x-chromosome
additive genes
a gene that contributes to the phenotype, usually with other additive genes
carrier
a person whose genotype includes a gene that is not expressed in the phenotype and such an unexpressed gene occurs in half the carrier's gametes and thus is passed on to half the carrier's children
dizygotic twins
aka fraternal twins and are twins who are formed when two separate ova are fertilized by two separate sperm are roughly the same time
monozygotic twins
aka identical twins and are twins who originate from one zygote that splits apart very early in development
allele
any of the possible forms of a gene
XY
consists of an X-shaped chromosome from the mother an a Y-shaped chromosome from the father, XY zygotes become males
XX
consists of two X-shaped chromosomes, one each from the mother and the father, XX zygotes become females
chromosome
each molecule of DNA
sons are more likely to have twins than daughters. true or false.
false, daughters are more likely to have twins than sons since they ovulate
dizygotic twins are different from a set of siblings the share the same biological parents. true or false.
false, they are NO different from a set of siblings the share the same biological parents
polymorphic
genes with various alleles
monozygotic twins have the same _______ but slight variations in the ______ due to environmental influences
genotype;phenotype
dominant-recessive pattern
interaction of a pair of genes in such a way that the phenotype reveals the influence of one more than that of the other
DNA
molecule that contains the chemical instructions for cells to manufacture various proteins
females are ___ likely to be carrier of x-linked traits but are ____ likely to express them
more;less
genotype
organism's entire genetic inheritance or genetic potential
zygote
single cell that is formed from the fusing of two gametes, a sperm and an ovum; when egg is fertilized by a sperm
gamete
single individual reproductive cell which is either sperm or ovum that can produce a new individual if it combines with a gamete from the other sex to form a zygote
gene
small section of a chromosome which is the basic unit for transmission of heredity that consists of a string of chemicals that provide instructions for the cell to manufacture certain proteins
copy number variations
small variations, mutations, or repetitions in the base pairs or triplets could make a notable difference in the proteins and in person
the 23rd pair
the chromosome that determines if your male or female
genome
the full set of genes of a certain species
phenotype
the observable characteristics of a person including appearance, personality, intelligence, and all other apparent traits
dizygotic twins have half their genes in common and occur twice as often as monozygotic twins. true or false.
true
monozygotic twins will always be the same gender. true or false.
true
older women are more often to double-ovulate. true or false.
true
vanishing twin phenomenon
when an early sonogram will reveal two developing organisms, but later on only one embryo continues to grow
methylation
when material enhances, transcribes, connects, empowers, silences, regulates, and alters genes
Human Genome Project
• Found "only" about 20,000 - 23,000 genes in humans