(L1) Overview & History of Cytogenetics Flashcards
microscopic investigations of the cork in 1665. He observed dead cork cells and introduced the term “cell” to describe them.
Robert Hooke
provided a number of illustrations
of plant material which indicate that he notices the cellular structure.
Nehemiah Grew
who is best remembered as a master of the art of grinding short focal length lenses, described many micro-organism, blood cells and spermatozoa in detail
Anton Van Leeuwenhoek
reported on cell division in algae
Demortier
described the nucleus
Robert Brown
sketched many features of mitosis
Con Mohl
Two Germans, the botanist _______ (in1838) and in the biologist _________ (in 1839), were among the first to clearly state that cells are the fundamental particles of both plants and animals. This pronouncement –_______ –was amply confirmed and elaborated by a series of discoveries and interpretations.
Matthias Schleiden; Theodor Schwann; the cell theory
in a series of studies showed that
fertilization involved fusion of two nuclei, one of which was derived from the male and the other from the female parent.
Oscar Hertwig
The 2nd development, generally credited to _________, it was the demonstration that gametic nuclei contained half the number of chromosomes of the zygote, from which it could be concluded that gametogenesis involved some type of reduction division in which maternal and paternal chromosomes segregated.
Eduard van Beneden
The 2nd development, generally credited to _______, it was the demonstration that gametic nuclei contained half the number of chromosomes of the zygote, from which it could be concluded that gametogenesis involved some type of reduction division in which maternal and paternal chromosomes segregated.
The significance of these findings were realized by ________ and led directly to the development of the _________
Eduard van Beneden; Weismann; Chromosome Theory of Heredity
_______ published a paper in which he described the results of certain crosses involving garden peas. He found that the contrasting characters with which he was concerned where distributed among the offspring according to a rather simple and precise mathematical formulation
Gregor Mendel
In 1901, modern science of genetics became
established with the basic concept that hereditary characters were determined by specific factors, later called _____, which were transmitted from parent to offspring through the gametes.
genes
The study of heredity, the process in which a parent passes certain genes onto their children.
Genetics
describes how some traits are passed
from parents to their children.
Heredity
The traits are expressed by _______ , which are small sections of DNA that are coded for specific traits
genes
Genes are found on ______
chromosomes
Applications of Genetics
- Plant & Animal improvement
- Medicine
- Genetic Counseling
- Legal Applications
- Genetic Engineering
Genetics can help healthcare professionals to identify certain conditions in babies before they are even born using techniques such as pre-natal testing.Genetic developments are used to help develop targeted medicine for certain diseases like diabetes.
Medicine
Plants and animals play a big role in our daily food consumption. With the rapidly increasing population, the demand of the food is increasing so the production must also cope up with the demand. By knowing the the genetic build-up the plant, farmers may better conserve them and increase the
production of the livestock. Animal improvement mainly focuses on animal
breeding which is based on the products like milk, meat, wool, and services produced by animals which function because of their genes. This can be achieved by selecting genetically superior animals to be the parents of the next generation.
Plant and animal improvement
- DNA Testing
- Genetic Fingerprinting to catch criminals
Legal Applications
Closely related to medicine in the application of genetics; Used to:
mass produce insulin for those who are
suffering with diabetes
produce human growth hormone,
treat infertility (Ex. IVF – test tube/design baby)
make vaccines and drugs
Genetic Engineering
Genetically determined quality or
characteristic of a person
Trait
Monogenic/Polygenic:
Controlled by one gene
Controlled by multiple genes
Monogenic; Polygenic
Monogenic/Polygenic:
Quantitative Inheritance
Meaning: All dominant alleles
are all contributing to the final
output
Qualitative Inheritance
Meaning: The final trait is just
determined by one particular
gene
Polygenic; Monogenic
Monogenic/Polygenic:
Number of intermediate forms Meaning: intermediate genes increase as the number of polygenes increase
No intermediates
Meaning: Whatever the parents
has, the parental phenotype
exist in the offspring also
Polygenic; Monogenic
Monogenic/Polygenic:
Gives discontinuous
variation
Meaning: Either tall or short (no
in between)
Gives continuous variation Meaning: A lot of possible results that can come out from a polygenic trait (white + red rose = pink rose)
Monogenic; Polygenic
Monogenic/Polygenic:
Does NOT follow Mendelian ratio
Follow Mendelian ratio
Monogenic; Polygenic
A child inherits two sets of genes – one from each parent (each person has two copies from ever gene)
These copies may come in different
variations, known as ____, that express
different traits
allele
In the nucleus of each cell, the DNA molecule is
packaged into thread-like structures called
_________.
CHROMOSOMES
Each chromosome is made up of DNA tightly coiled
many times around proteins called ______ that
support its structure.
HISTONES
Each chromosome has a constriction point called ______ , which divides the chromosome into two section, or “arms”
centromere
The short arm which is the ______
“p arm”
The long arm which is the ______
“q arm”
A variant form of a gene
Alleles.
Humans are ________ because they have 2 alleles at each genetic locus, which one allele inherited from each parent.
diploid organism
Refer to the exact pairing of alleles (letters); is not concerned with the expression
Genotypes
2 things being the same
Homozygous
2 things differnet/distinct
Heterozygous
