Genetics Unit Review Flashcards
Heredity
Describes how some traits are passed on.
Alleles
Alleles are different versions of the same gene.
Ex) you inherit one allele for blue eyes and another for brown eyes, together they determine the colour of your eyes as they are the same gene but are different versions.
Law of Dominance
When different alleles for a characteristic are inherited, only one will be expressed (the dominant one).
Law of Independent Assortment
When alleles of two or more different genes get sorted into gametes independently of one another.
Sex Linkage
Genes located on the X chromosome are inherited with that X.
Gene Flow
is the process of genes being transferred from one population to another.
Chromosomal Abnormalities
Numerical abnormalities- are whole chromosomes either missing or extra to the normal pair.
Structural abnormalities- are when part of an individual chromosome is missing, extra, switched to another chromosome, or turned upside down.
Chargaff’s Rule
Shows that in natural DNA, the number of guanine (G) units equals the number of cytosine (C) units and the number of adenine (A) units equals the number of thymine (T) units.
DNA Replication
-Happens in the cell’s nucleus.
-Makes an exact copy of the original DNA molecule.
-C matches with G (or G with C)
-A matches with T (or T with A)
Condon/Anticodon
Codon = Found in mRNA, tells which amino acid to add. It transfers genetic information from the nucleus to the ribosomes.
Anticodon = Found in tRNA, pairs with the codon to bring the right amino acid.
Genetics
is the study of heredity, the process in which a parent passes certain genes onto their children.
Traits (Dominant vs Recessive)
Dominant- one allele will cover over the other allele for a particular trait and will be passed onto the offspring (trait that shows).
Recessive- alleles only show up when two copies of the recessive allele are inherited.
Law of Segregation
Parents pass only one of their two gene copies to their children, chosen at random. (ex. eye colour)
Phenotype vs Genotype
Genotype- the instructions coded in your DNA that you inherited from your parents.
Phenotype- This is the actual result of those instructions—how your traits show up physically or behaviorally. Ex) includes things like your eye color, height, or even how you respond to certain environments.
Multiple Alleles
3 or more allele of the same gene that code for a single trait. ( there are many “options” for a gene, but you only get one of them.)
Genetic Drift
It changes the frequency of genes (or alleles) in a small population over time, there is a chance of disappearance of particular genes as individuals die or do not reproduce.
Karyotypes
A picture of a person’s chromosomes.
Amino Acids
the building blocks of proteins, which are essential for carrying out the instructions in genetic material (DNA).
Transcription
- Making the message: the DNA nucleotide sequence is copied from DNA to mRNA.
2.mRNA message is complete: mRNA carries message and leave the cell nucleus to the cytoplasm.
Translation
-Message from mRNA is translated to a specific protein.
-tRNA looks for a specific amino acid in the cytoplasm that it can take to the ribosome to join with a certain codon, finding other amino acids to form protein.
-tRNA then is free to find more of the same amino acid to make protein.
Mutation
A change in the DNA sequence of a living organism.
Types:
Duplication- addition of gene
Deletion- loss of gene
Inversion- rotation of a gorup of genes within one chromosome
Translocation- Exchange of parts between chromosomes of different pairs
Gene
are small sections of DNA that are coded for specific traits.
Heterozygous
two alleles in the gene are different
Homozygous
two alleles in the gene are the same
Incomplete Dominance
When one allele is not completely dominant over another.
EX) crossing a red flower with a white flower and ending up with a pink flower
Codominance
When both alleles show up in the offspring.
Ex) a black rooster and white chicken mate. They produce all offspring that are black and white spotted.
Meiosis
cell division in reproductive cells. It is a two-phase process that divides the chromosome of a diploid germ cell, generating four haploid gametes.
DNA vs RNA
-RNA has ribose sugar while DNA has deoxyribose sugar.
-RNA has uracil while DNA has thymine.
-RNA is single stranded while DNA is double stranded.
-RNA can leave the nucleus (carries the message) while DNA can’t leave the nucleus.
Nucleotides
The basic building blocks of DNA and RNA that contain a sugar, phosphate, and nitrogen base. It is the molecules that store and transfer genetic information in living things.
Adenine
Guanine
Cytosine
Thymine
Epigenetics
is like a “control system” for your DNA. It involves changes that affect how your genes work without changing the actual DNA sequence. (describes passing on the way genes are used)
Gregory Mendel
Credited for the Mendelian Inheritance which is the simple inheritance of dominant and recessive genes.
Johannes Friedrich Mischer
credited with the discovery of nucleic acids which is now referred to as DNA (deoxyribonucleic acid) and RNA (ribonucleic acid).
Erwin Chargaff
found that in DNA, the ratios of adenine (A) to thymine (T) and guanine (G) to cytosine (C) are equal.
Rosalind Franklin
revealed the double helix of DNA
James Watson and Francis Crick
Their joined work led to the identification of the structure of DNA.
What are the P1, F1, and F2 generations?
P1 Generation (parental generation)- The first set of parents in a breeding experiment. These are the original individuals with specific traits that are being studied.
F1 Generation (First Filial Generation): The offspring of the P1 generation.
F2 Generation (Second Filial Generation): The offspring of the F1 generation.
Gene Mutations: Point mutation, frameshift mutations
Point Mutation- is a small change in the DNA sequence where a single building block (called a nucleotide) is altered. DNA is like a long string of letters (A, T, C, G), and a point mutation changes just one of those letters.
Frameshift- is like a typo in the genetic instructions of a cell. It happens when DNA loses or gains one or more “letters” (bases), which shifts the way the cell reads the genetic code.
What is a trisomy/monosomy? What were some the chromosomal abnormalities we discussed?(Turners syndrome, Down syndrome, etc.)
Trisomy means having an extra copy of a chromosome.
-Down syndrome is a condition that happens when a person is born with an extra copy of chromosome 21.This extra chromosome affects how the body and brain develop, which can lead to differences in learning, growth, and physical traits.
Monosomy means having a missing copy of a chromosome.
-Turner syndrome is a condition that affects only females and happens when one of their X chromosomes is missing or incomplete. There can be changes in height, delayed puberty,
what is DNA composed of? what nucleotides are paired up with each other?
DNA (Deoxyribonucleic Acid) is like a twisted ladder made of:
Sugar and Phosphate Backbone: The sides of the ladder.
Nitrogenous Bases: The “rungs” of the ladder are made of four chemical bases:
Adenine (A)
Thymine (T)
Cytosine (C)
Guanine (G)
The bases pair up in a specific way:
Adenine (A) pairs with Thymine (T).
Cytosine (C) pairs with Guanine (G).
what is dna replication? how is polymerase, primate, and helicase and ligase involved?
DNA replication is the process by which a cell makes an exact copy of its DNA before dividing.
Helicase: Unzips the DNA strand.
Polymerase: The builder replicates the DNA to build a new strand.
Primase: The initializer that makes the primer fot the polymerase.
Ligase: Helps glue DNA fragments together.
What is RNA? mRNA? tRNA?
RNA: is a molecule in living things that helps turn instructions in DNA into proteins, which do most of the work in cells. You can think of RNA as a messenger or helper.
mRNA: messenger RNA
tRNA: transfer RNA (transfers message)
