Quiz 1 Deck Flashcards
(30 cards)
List the three major divisions of genetics and what each includes
Transmission : focused on individual, refers to how traits are passed on from one generation to next
Population: explore the genetic composition of populations and how they change geographically over time, focus is on the GROUP of genes in a population
Molecular: looking at gene itself, gene structure, formation organization
describe common features of most model genetic organisms
-short generation time
-large but manageable population size
-adaptability for lab
-inexpensive to house and propagate
-the availability of numerous genetic variants
-an accumulated body of knowledge about their genetic systems
compare the theory of pangenesis and the germ plasma theory
PANGENESIS: NOT TRUE CONCEPT, EACH PART OF BODY CONTAINS GENETIC INFO gemmules, carry information from parts of the body to the reproductive organs, then passed to embryo at the moment of conception
Germ-plasm theory : A CORRECT THEORY
weismann, cells in reproductive organs carry a complete set of genetic into that is passed to the egg and sperm, egg and sperm has info already
define preformationism
a concept of herdity where inside the egg is a fully formed minature adult; a homunculus, that simply enlarges in the course of development
all traits inherited from only one parent
explain blending inheritance
traits of offspring area blend or mixture of parental traits (mom red hair dad blue hair kids purple hair)
compare the different concepts of heredity
correct ones are mendalian, germ plasm, and cell theory the rest are all incorrect
briefly describe mendels contribution to genetics
traits are inherited with defined principles, depends on what trait is to see how/what is inherited.
his conclusion of monohybrid crosses
- one character is encoded by two genetic factors
-two genetic factors (alleles) separate when gametes are formed
the concept of dominant and recessive traits
-two alleles separate with equal probability into the gametes
compare eukaryotic and prokaryotic cells
Prokaryotic cells are single celled with an absolute nucleus and they are relatively small prokaryotic cells usually have one circular DNA molecule DNA are not complex with histones in bacteria some histones in Archea a relatively small amount of DNA and membrane bound organelles are absent
Eukaryotic cells are unicellular or multicellular they have a present nucleus and they are relatively large they have multiple linear DNA molecules to form a genome in their DNA is complexed with histones the amount of DNA is relatively large membrane-bound organelles are present
give definition of a gene
they are the fundamental unit of heredity
Come in multiple forms called alleles
Confer phenotypes
Are located on chromosomes
explain the relationship between genes and alleles
genes come in multiple forms called alleles
a gene is an inherited factor(encoded in the DNA) that helps determine a characteristic
explain the relationship between genotype and phenotype
a genotype is a set of alleles possessed by an individual organism
a phenotype (or trait) is the APPEARANCE or manifestation of a characteristic
explain the relationship btwn genes and chromosomes
Genes are located on chromosomes
chromosomes seperate through mitosis and meiosis
briefly describe the function of mitosis and meiosis
Mitosis purpose is cellular proliferation CELLULAR DUPLICATION, chromosome number remains the same and genetic variation doesn’t change, 2 diploid daughter cells produced
meiosis’s purpose is sexual reproduction, chromosome number is halved in each daughter cell and genetic variation is increased, 4 haploid daughter cells are produced
explain the relationship between DNA,RNA, and proteins
DNA -> RNA -> PROTEINS IS CENTRAL DOGMA,
GENETIC INFO IS CARRIED IN DNA AND RNA
DNA contains the information necessary for encoding proteins, although it does not produce proteins directly. RNA carries the information from the DNA and transforms that information into proteins that perform most cellular functions
define mutation
Mutations are permanent changes
explain how traits are affected by multiple factors
Most traits are shaped both by a person’s genes and by environmental factors. Environmental factors include everything outside of DNA that affects your traits. They are very broad and can influence you in many ways, either alone or in combination with genes.
describe how evolution occurs
evolution is genetic change overtime
chromosomal duplication can influence evolution
reprodcution alone will not bring about evolution
explain the relationship of bacteria and eukaryotes
The leading hypothesis, called the endosymbiotic theory, is that eukaryotes arose as a result of a fusion of Archaean cells with bacteria, where an ancient Archaean engulfed (but did not eat) an ancient, aerobic bacterial cell.
Antibiotics that do not inhu=ibit protein synthesis in eukaryotes inhibit protein synthesis in bacteria and mitochondria
The most obvious difference between eukaryotes and bacteria is that there is a membrane-bounded nucleus in eukaryotes and not in bacteria
decribe the process of binary fission in prokaryotes
a part of cell reproduction
binary fission: separation of replicated circular chromosome
describe 3 functional elements of eukaryotes chromosome and their functions
chromatin: complex of dna and proteins
histone proteins : the most abundant proeitns in chromatin
nucleosome: consist of DNA wrapped around an octamer of eight histone proteins
centromeres: constricted region of a chromosome where spindle fibers attach
telomeres: end of chromosomes that stabilize the chromosomes
summarize the key genetic consequences of the cell cycle
Cycle produces two cells that are genetically identical to each other and the parental cell
new cells contain approximately half the cytoplasm and organelle content of the original parental cell
cytoplasm and genetic cells not necessarily identical
predict the number of chromosomes and number of DNA molecules found in a cell at different stages of the cell cycle
G1: 4 chromosomes per cell and 4 Dna molecules per cell
S: 4 chromomes per cell and 4-8 DNA
G2 4 chromosomes and 8 DNA molecule per cell
Prophase and prometaphase: 4 chromome and 4 DNA
Metaphase: 4 chromosomes and 8 DNA molecules per cell
Anaphase : 8 chromosomes and 8 DNA molecules
Telophase and cytokinesis: 4 chromosomes and 4 DNA
outline the important events that occur in each stage of meiosis
Meiosis describes the process of cell division by which gametes are made. In this process, we begin with a cell with double the normal amount of DNA, and end up with 4 non-identical haploid daughter gametes after two divisions.
There are six stages within each of the divisions, namely prophase, prometaphase, metaphase, anaphase, telophase and cytokinesis.
https://teachmephysiology.com/biochemistry/cell-growth-death/meiosis/#:~:text=In%20this%20process%2C%20we%20begin,%2C%20anaphase%2C%20telophase%20and%20cytokinesis.
Meiosis I
In meiosis I, homologous chromosomes are separated into two cells such that there is one chromosome (consisting of two chromatids) per chromosome pair in each daughter cell, i.e. two chromosomes total.
Prophase I
Prior to prophase, chromosomes replicate to form sister chromatids. There are initially four chromatids (c) and two chromosomes (n) for each of the 23 chromosome pairs (4c, 2n). The nuclear envelope disintegrates and the chromosomes begin to condense. Spindle fibres appear which are important for the successful division of the chromosomes.
To further increase genetic diversity, homologous chromosomes exchange small parts of themselves, such that one chromosome contains both maternal and paternal DNA. This process is known as crossing over, and the points at which this occurs on a chromosome are referred to as chiasmata.
Prometaphase I
Spindle fibres attach to the chromosomes at points along the chromosomes called centromeres. While this is happening, the chromosomes continue to condense.
Metaphase I
Maternal and paternal versions of the same chromosome (homologous chromosomes) align along the equator of the cell. A process called independent assortment occurs – this is when maternal and paternal chromosomes line up and randomly align themselves on either side of the equator. This in turn determines which gamete chromosomes are allocated to, which leads to genetic diversity among offspring.
Anaphase I
Here, each of the homologous chromosomes is pulled towards opposite poles of the cell as the spindle fibres retract. This equally divides the DNA between the two cells which will be formed.
Telophase I and Cytokinesis I
During telophase I, the nuclear envelope reforms and spindle fibres disappear. In cytokinesis I, the cytoplasm and cell divide resulting in two cells that are technically haploid – there is one chromosome and two chromatids for each chromosome (2c, n).
summarize the key genetic consequences of meiosis
Four cellls are produced from each originial cell
chromosome number in each new cell is reduced by half
newly formed cells from meiosis are genetically different from one another and from the parent cell
