Week 7 Genetics Flashcards
How do scientists reference chromosomes?
For reference purposes, scientists have assigned numbers to the chromosomes using an order based on length.
What is a recessive allele?
Two copies of the allele need to be present for the phenotype to be expressed.
- lower case
How much heredity to children share with parents?
- Children get half their genetic material from each parent
- They have a 50% chance or 0.50 of sharing any particular gene with either parent
What do genes do?
encodes the synthesis of a gene product, either RNA or protein.
- code for the production of proteins so that when that gene is activated the cell produces that specific protein
- found within the chromosomes
- carry the information that determines your traits, which are features or characteristics that are passed on to you — or inherited — from your parents.
What is the difference between genotype and phenotype?
What is Heredity?
the passage of characteristics from parent to offspring by way of genes
What is an example of a phenotype where a single gene has only two alleles in humans?
ear wax has only 2 alleles
- either wet or dry
- can use punnett square for this
What is the fundamental issue of human behaviour?
The fundamental issue of human behaviour is how the factors of genes and the environment interact to shape human behaviour
What can be used to represent dominant versus recessive traits?
punnett square
What are alleles?
different variants of a gene
- Alternative forms of a gene that produce different characteristics
What is RNA?
similar to DNA, creating when genes are expressed
- Ribonucleic acid is a polymeric molecule essential in various biological roles in coding, decoding, regulation and expression of genes.
What is the meaning of Mendelian genetics?
Proposes the idea of dominant and recessive traits
What cells have only 23 chromosomes?
Except sex cells, which only contain 23 chromosomes
- two X chromosomes in females
- one X and one Y chromosome in males
What are genes?
units of hereditary transmission (genetic blueprints)
- a basic unit of heredity and a sequence of nucleotides in DNA or RNA
What are chromosomes?
strands of DNA wound around each other in a double-helix configuration and partly coated in protein
- with part or all of the genetic material of an organism. Most eukaryotic chromosomes include packaging proteins called histones which, aided by chaperone proteins, bind to and condense the DNA molecule to maintain its integrity.
What are amino acids?
“building blocks of life”
- function as the building blocks (monomers) of proteins, which polymerize together and fold into a particular shape and will then perform a specific function
Who coined Mendelian genetics?
Gregor Mendel in 1865 and 1866
What is phenotype?
observable characteristics of a gene
- The term covers the organism’s morphology or physical form and structure, its developmental processes, its biochemical and physiological properties, its behavior, and the products of behavior.
How much heredity do children share with grandparents?
- You have a 0.25 probability of sharing a particular gene with your grandparents
- 0.50 x 0.50 or 0.25
What are some examples of phenotypes?
- include height, wing length, and hair color.
- Phenotypes also include observable characteristics that can be measured in the laboratory, such as levels of hormones or blood cells.
What is the human genome project?
an international scientific research project with the goal of determining the base pairs that make up human DNA, and of identifying and mapping all of the genes of the human genome from both a physical and a functional standpoint.
How much heredity do children share with siblings?
Brothers and sisters also have a probability of 0.50 sharing the same gene with each other
What are dizygotic twins?
fraternal
- two eggs (ova) are fertilised by two sperm and produce two genetically unique children.
- share 50% of genes
How much heredity to children share with half siblings?
• It is also 0.25 probability for half siblings
What is DNA?
(deoxyribonucleic acid): chemical substance containing nucleotides
Describe the ladder of life
what two alleles do humand receive for every gene?
- Homozygous
- Heterozygous
What is an example of a disease where a single gene has only two alleles in humans?
Huntingtons disease
- Variation on a single gene with 2 alleles
- having the dominant leads to disease
- changes in function of basal gingival which effect movement
How many genes do human have?
~25000-35000
What is epigenome?
Information about us stored outside of our DNA (tags that become attached to our DNA)
- An epigenome consists of a record of the chemical changes to the DNA and histone proteins of an organism;
- these changes can be passed down to an organism’s offspring via transgenerational stranded epigenetic inheritance
What is a heterozygous gene?
a combination of alleles for a given genes
What is a dominant allele?
In genetics, dominance is the phenomenon of one variant of a gene on a chromosome masking or overriding the effect of a different variant of the same gene on the other copy of the chromosome
- only need one copy
- upper case
What is a polygenetic trait?
A polygenic trait is one whose phenotype is influenced by more than one gene
- Traits that display a continuous distribution,
- height or skin color
- Very few characteristics controlled by single gene with 2 alleles
What is a genotype?
Specific genetic make-up of an individual
- A genotype is an organism’s complete set of genetic material.
- Often though, genotype is used to refer to a single gene or set of genes, such as the genotype for eye color. The genes take part in determining the characteristics that are observable in an organism, such as hair color, height, etc.
How can genetics and epigenetics be compared to music?
- genetics = sheet music
- epigenetics = How music is played by the musician
What shapes human behaviour?
nature and nurture
Both genes (nature) and the environment (nurture) interact to shape human behaviour
What is epigenetic’s?
Above genetics
- Lasting changes in gene function caused by external or environmental factors without any change in the DNA itself
- Activate or silence gene (turn “on” or “off”)
- Alter how gene functions (gene expression)
How many chromosomes are in humans?
23 pairs of chromosomes for a total of 46 in each cell of the body
What are monozygotic twins
identical
- one fertilised egg (ovum) splits and develops into two babies with exactly the same genetic information
- share 100% of genes
What is an example where a change in a single gene can lead to severe changes in development?
Phenylketonuria (PKU)
- Increased levels of phenylalanine,a building block of proteins
- Toxicity in neurons builds up and leadst o neuronal death
- Leads to a very severe changes in development:
- Intellectualdisability
- Delayeddevelopment
- Behavioralproblems
- Psychiatricdisorders
What are some examples of alleles?
- APOE4 allele (effects hippocampus) is associated with an increased risk of Alzheimer’s disease
also:
- Attached earlobe or not
- Tongue rolling or not
What is a genome?
complete set of genetic material for an organism
What is the homozygous gene?
an identical pair of alleles for a given gene
