Genetics Flashcards
The study of the process by which information is transmitted from one generation of living things to the next
Genetics
Every living thing is organized via coded information, called
(Same word) Reproduction involves duplication and transmission of an organisms _______.
Genetic Material
An information entity. It is a sequence of DNA that codes for a single genetic instruction
Usually, this instruction is the sequence of a protein, but a gene may also serve to activate or deactivate other genes, in a cell, or in neighboring cells.
Gene
Every aspect of our species is constructed based on information encoded in
By themselves do very little, they are information storage molecules. It is the cytological machinery of our cells, passed from one generation to the next, that translate these instructions into a living organism.
Genes
The effects of every gene depend both upon other genes, and upon the environment.
Word!
ONE variant of a gene. Many genes have two, several, or many different variants of the same basic genetic information.
Allele
T/F: Some alleles are minor differences that to not significantly affect the organism, others cause profound changes.
True
Nucleotide substitutions in which codon position often produces no change at all, because they code for the same transfer RNA and thus the same protein is produced
Third Codon
Ex: humans…CCUv=>CCA does not cause a change, both triplets code for proline.
mkay
Other substitutions may produce profound effects, sickle cell anemia is caused by a single nucleotide substitution: GAG => GUG. What does it cause?
Normal hemoglobin sickles, or has an abnormal shape and becomes rigid, under low oxygen concentrations
the simplest, oldest, and most common organisms on the planet.
Prokaryotes (Archea and Bacteria)
A typical prokaryote has a much smaller genome than a typical eukaryote, nearly always it’s in the form of what?
Note: It’s still a lot of DNA in a single bacterium, stretched out it is 500 times longer than itself
a simple loop of DNA with associated proteins
Where is the DNA loop in prokaryotes attached?
To the cell membrane
Do prokaryotes have sexual reproduction?
Do they have gene exchange?
No.
Yes. Ex: Swapping plasmids.
Is there a functional grouping to the order of genes arranged along the length of the chromosome?
No, evolutionary chance determines it.
In prokaryotes, the DNA loop replicates before fission with both loops where?
Attached to the cell membrane
-One loop of DNA ends up in each new daughter cell.
Most eukaryotes have how much more DNA than a typical prokaryote?
Several orders of magnitude
Eukaryote genes are arranged along the length of a chromosome, like prokaryotes. Is their a functional reason for their location on the chromosome or which they’re on?
No, it’s an evolutionary accident.
Eukaryote DNA is usually circular or linear?
What is one exception
Linear
Plastid DNA - similar to bacterial DNA
What are the linear strands of DNA called?
Where are they packed?
Chromosomes
The nucleus
In multicellular eukaryotes, does every cell have the same DNA?
Yes
What explains differences in function between cells?
Only a fraction of the genes are active in certain cells.
These are very important and very evolutionarily conservative proteins. Loops of DNA are wrapped around one of them and locked in
Histones
What locks in the loops of DNA and histones?
Nucleosome
duplication of the genetic material within a eukaryote cell in which a cell gives rise to two smaller but genetically identical copies of itself
Mitosis
Mitosis can lead to growth in a what type of organism?
Mitosis can lead to asexual reproduction in what type of organism?
Multicellular
Single Celled
Is mitosis a means of producing gametes?
No.
In sexual organisms, what does mitosis do?
Gives rise to cell types which kill themselves off by splitting and splitting again into four very different cells
a particular type of reproduction, a sharing of genetic material, to form an individual with equal contributions from two separate parents.
Sexual Reproduction
A haploid sex cell that is formed from a diploid cell during meiosis
Gamete
A combination of genetic information from two separate cells to form a diploid cell (aka zygote)
Syngamy (fertilization)
Sex probably evolved as a means of producing variable offspring in the face of an uncertain future, though its evolutionary origins are obscure.
It is virtually ubiquitous among eukaryotes, though many can produce sexually or asexually.
It has the potential to produce enormously variable sets of genetic information, something that can be crucial to the survival of a species.
K
In some organisms, the haploid phase of the life cycle is multicellular, and haploid individuals simply grow together during the process of syngamy
K
the state of having two copies of every single gene -like pairs of shoes, pairs of gloves, pairs of stereo speakers.
Diploidy
Flies, Zebras potatoes, and humans are haploid or diploid?
Diploid - we have two copies of every gene in our bodies
Identically matched copies of a gene
homozygous
Subtly different copies of a gene
heterozygous
Are all organisms diploid as adults?
No, some are haploid.
For sexual reproduction to occur, there must be a haploid and diploid phase of the life cycle.
Word.
The process by which a single diploid cell gives rise to four, genetically different, haploid cells.
Meiosis
The diploid progenitor duplicates its genetic material…thus, every chromosome is composed of two, identical…
chromatids
Where are the two chromatids joined?
Centromere
Each chromosome finds its match, to form “matching pairs” of homologous chromosomes. This process occurs during the first of the two meiotic divisions. Does this occur during mitosis?
No, it is unique to meiosis
The four stands cluster in structures called _____ along the center of the dividing cell
Tetrads
These drag each side of each chromosome to the opposite poles of the cell.
Spindle Fibers
Is where a chromosome ends up planned or random?
Is it influenced by the fate of the other chromosomes around it?
Random.
No.
The cell divides and the spindle fibers once more drag them to othe opposite poles of the cell. The cell then divides.
How many genetically different daughter cells are formed?
4.
Are the four cells haploid or diploid?
Haploid
What does meiosis create?
What does it ensure in offspring?
Gametes (sperms and eggs)
Variability