Chapter 2 Flashcards
pangenesis
idea that particles throughout the body can be influenced by the activities of an organism…modify the sex cells in a way that acquired characteristics can be passed on to the next generation. discredited
Gregor Mendel
pea plant experiment,
true-breeding
showing the same traits without exception over many generations
hybrids
individuals that are the result of a cross breeding between 2 different kinds of parents
dominant
the trait that is seen in the hybrid
recessive
the trait that is not seen
segregation
(in the formation of sex cells) the process in which paired hereditary factors separate, forming sex cells that contain either one or the other factor
back cross
the process of crossing a hybrid with its homozygous recessive parent
independent assortment
Mendelian principle, states that differing traits are inherited independently of each other
phenotype
the observable and measurable characteristics of an organism
trait
one aspect of the phenotype
genotype
the genetic constitution of an individual
monozyqotic twins
identical twins: derived from a single zygote
zygote
fertilized ovum
dizygotic twins
fraternal twins
genes
sections of the genetic material that have specific functions
alleles
alternative forms of a gene
homozygous
having two like alleles of a particular gene:
homozygous dominant when the allele is dominant
homozygous recessive when gene is recessive
homozygous dominant
two dominant alleles of the same gene
homozygous recessive
two recessive alleles of the same gene
phenylthiocarbamide
artificially created substance whose main use is in detecting the ability to taste it; relates to inherited dominance
heterozygous
having two different alleles of a particular gene
cytogenetics
study of the hereditary mechanisms within the cell
cell
the smallest unit able to perform all those activities collectively called life. All living organisms are either one cell or composed of several
plasma membrane
a structure that binds the cell but allows for the entry and exit of certain substance
nucleus
structure found in the cell that contains the chromosomes
nuclear membrane
binds the nucleus within the cell
cytoplasm
material within the cell between the plasma membrane and the nuclear membrane
chromosomes
bodies found in the nucleus of the cell that contain the hereditary material
chromatids
strands of replicated chromosomes. joined together by centromeres
centromere
structure in the chromosomes holding the 2 chromatids together
during cell division, it is the site of attachment for the spindle fibers
karyotype
the standardized classifications and arrangement of chromosomes
homologuous chromosomes
chromosomes of the same pairing containing the same genes but not necessarily the same alleles
sex chromosomes
X and Y males XY, females XX
autosomes
chromosomes other that sex chromosomes
mitosis
form of cell division whereby one-celled organisms divide and body cells divide in growth and replacement
meiosis
form the cell division occurring in specialized tissues in the testes and ovaries that leads to the production of gametes or sex cells
gametes
a sex cell produced by meiosis that contains one copy of a set of a chromosome set (23 in humans)
estrus
time period during which the female is sexually receptive
linkage
association of genes on the same chromosome
atoms
the building blocks of matter
molecules
units composed of two or more atoms linked by chemical bonds
carbohydrates
organic compounds that includes fats, oils, and waxes
proteins
long chains of amino acids joined together by peptide bonds (a polypeptide chain)
amino acids
molecules that are the basic building block of proteins
peptide bond
a link between amino acids in a protein
polypeptides
chains of amino acids
nucleic acids
the largest of the molecules found in living organisms (made of nucleotides)
nucleotide
the basic building bolck of nucleic acids; composed of a five carbon sugar
ribose
a five carbon sugar found in RNA
deoxyribose
a five-carbon sugar found in the DNA molecule
phosphate unit
a unit of nucleic acid molecule consisting of a phosphorus atom and four oxygen atoms
base
a subunit of a nucleotide that makes up the DNA and RNA molecules; adenine, thymine, uracil, guanine, cytosine
deoxyribonucleic acid (DNA)
a nucleic acid that controls the structure of proteins and hence determines inherited characteristics
mitochandria
bodies found in the cytoplasm that convert the energy in the chemical bonds of organic molecules into ATP
