Kevin’s Cards about Genetics and Heredity Flashcards
Genetics Definition
The study of how heritable characteristics are determined and passed from parents to offspring
Heredity Definition
The ability to pass on genetics traits, such as color of the eyes, from parent to child through DNA
When did the understanding of genetics begin
The understanding of genetics began with a 19th century Augustinian monk who grew pea plants in the garden of a monastery in Austria, named Gregor Mendel
Who is considered the father of genetics
Gregor Mendel
Heritable Definition
Transmitted from parents to offspring regardless of environment
What is a Genetic Counselor
A person who has studied genetics and advises people on genetic issues, such as diseases
What did Gregor Mendel notice about pea-plants
Gregor Mendel noticed pea plants had certain identifiable and measurable features, or characteristics
Characteristics Definition
An identifiable or measurable feature of an organism, such as size, color, or texture
What features did Mendel notice about pea plants
Height, flower color, and seed texture
What did Gregor Mendel wonder about pea plant’s characteristics
He wondered if these went from generation to generation
Due to his wonder of heritable traits in pea plants, what did Mendel do to find out of pea plant characteristics go from generation to generation
To find out, Mendel cross-pollinated pea plants exhibiting different characteristics and observed the offspring. He then crossed the offspring with one another to see which characteristics showed up in the next generation of plants. He observed that some characteristics, such as flower color, seed shape, and seed color, were heritable, or passed on from parents to offspring regardless of environment
Cross Pollination Definition
The process of transferring pollen from the anther of one flower to the stigma of another flower. In Mendel’s investigation, the pollen was transferred from the anther of a flower on one plant to the stigma of a flower one a different plant
Factors Definition
The term Mendel used to describe what he hypothesized must be in all cells of organisms that determine the way traits are transmitted from parents to offspring
What did Mendel reason about the way traits are inherited
Mendel reasoned that certain factors in the cells of an organism determined the way traits are transmitted from parents to offspring
The qualities Mendel observed in his pea plants are referred to what today
Traits
Trait Definition
The specific observable form of an inheritable characteristic, such as tall height, pink for flower color, or smooth for seed texture
What is a true-breeder
A plant that pollinates itself
What is an independent variable
The factor that changes or manipulates in an experiment
What is a dependent variable
The dependent variable responds to the independent variable, which is what the scientists measure
What generation are the original two plants that Mendel used in
The parent generation
What generation are the first set of offspring Mendel produced
The first generation
What realization of Mendel was critical to his understanding of inheritance
His realization that the first-generation plants were not true-breeding
Dominant Definition
The characteristic of a trait that is expressed whether the trait is passed on from one or both parents
What did Mendel hypothesize about the dominancy of traits in the pea plants
He hypothesized that one factor, trait from parent, is dominant over the other
Recessive Definition
The characteristic of a trait that is never expressed in the presence of a dominant trait, and is expressed only if the trait is passed on from both parents
Why do true-breeding plants produce identical offspring
The factors of a particular trait in true- breeding plants therefore must be the same (for example YY or yy). This is why true-breeders keep producing the same type of progeny when crossed with themselves
What are the basic units of inheritance called
The basic units of inheritance, which Mendel called factors, are called genes by scientists today
Genes Definition
A section of a chromosome that typically contains the code for a particular protein, which determines a specific trait
What are scientists referring to when talking about genes
When scientists talk about genes, they are typically referring to sections of DNA that control the production of the cell’s proteins - and hence all of the activities and characteristics of an organism
True of False: There are different forms of the height gene that can make a plant grow tall or remain short
True
What determines if a pea plant is tall or short
Whether a pea plant is tall or short depends on which alleles of a gene that plant carries
Alleles Definition
One of the form s of a gene
True or False: In any species where there are two parents, the offspring will inherit one form, or allele, of a gene from each parent
True
What is the non-dominant allele known as
The recessive allele
What are the most important proteins in your body
Many of the most important proteins in your body are enzymes, which can speed up chemical reactions
What is the “Central Dogma”
The central dogma or rule of molecular biology depicts the flow of genetic information is from DNA to RNA to protein. This was created by Francis Crick
DNA Definition
Heredity material in a double-helix shape
What are chromosomes
Large bundles of tightly coiled DNA. Different organisms have different numbers of chromosomes. Humans have 23 pairs in each non-sex cell for a total of 46 chromosomes
What does each gene contain
Each gene contains typically the code for a single protein
What does DNA stand for
Deoxyribonucleic acid
How many chromosomes does a sex cell have
A sex cell has exactly 23 chromosomes, or 1/2 the number of chromosomes you would find in another type of cell
Why do sex cells only have 23 chromosomes instead of 46
Sex cells have half the number of chromosomes as other body cells because during the process of fertilization, one cell from each of two parents combines to form a new organism
True or False: Specific chromosomes in sex cell come together to form pairs
True
Due to fertilization, what type of chromosomes does the resulting offspring have
The resulting offspring has the chromosomes of two sex cells
When specific chromosomes in sex cells come together to form pairs, what are the two chromosomes in the pairs called
Homologous chromosomes
Homologous Chromosomes Definition
Chromosomes of the same type, which have the same form and the same genes, but not necessarily the same alleles for any given gene
How do the genes compare between homologous chromosomes
Each chromosome in a homologous pair of chromosomes carries the same set of genes as its homolog, or partner
How do the alleles compare between homologous chromosomes
Each half of a pair of homologous chromosomes contains one of the two alleles that a pea plant inherits for seed color
Chromosomes Definition
A threadlike structure of nucleic acids and proteins that carries genetic information in the form of genes within a cell’s nucleus
Karyotype Definition
A picture of all the chromosomes found in a single human cell
What happens if both alleles in a pair of genes are the same
If both alleles in a pair of genes are the same, then the organism is said to be homozygous for that trait
Homozygous Definition
Having two identical alleles for a gene being considered
What does homo mean
“The same”
What happens if both alleles in a pair of genes are different
If each allele from a pair of genes is different, the organism is said to be heterozygous for that trait
Heterozygous Definition
Having two different alleles for a gene being considered
What does hetero- mean
Different
What are the chromosomes of females
XX
What are the chromosomes of males
XY
The sex of the offspring is determined by which parent
The male parent
In the early 1900s, who created the Punnett square
Reginald Punnett
Punnett Square Definition
A grid used to predict the results of genetic crosses
Genotype Definition
The particular alleles present in an organism for a characteristic or a set of characteristics
Phenotype Definition
The particular traits expressed, or visible, for a set of characteristics
Species Definition
A taxonomic category representing a group of individual organisms that resemble one another closely and are able to interbreed
Hybrids Definition
In genetics, the word hybrid is used to describe any heterozygous individual. But it is also used to describe offspring born of parents of different species
Organisms within a species usually have what
Organisms within a species often have different alleles of a trait
Why do you look different from your parents
Because of your genes
Why do humans look different from one another
Because they have different combinations of alleles
Why do humans look similar to one another
Since they have the same number and kinds of chromosomes
Variation Definition
Differences that exist between individuals of the same species
True or False: Each species carries a certain number of chromosomes and certain kinds of chromosomes
True
True or False: Having more chromosomes means a species is more complex
False
True or False: Having more genes does not make a species more complex
True
True or False: Each species has a unique set of chromosomes and genes
True
Genetic Codes Definition
Typically, species that are closely related or that evolved from a common ancestor will share similar genes
True or False: The more genes two species have in common, the more similarities they will have
True
True or False: DNA, the blueprint of life, makes copies of itself so that organisms can pass on their genetic information to their young
True
DNA Definition
Deoxyribonucleic acid; this is the molecule, unique to each individual, carrying the genetic information to be found in every cell; all the information an organism needs to live and reproduce is contained in its DNA
Chromosomes Definition
A single long molecule of DNA wound around special proteins
How are chromosomes in eukaryotes like
In eukaryotes, chromosomes tend to be linear
How are chromosomes in prokaryotes like
In prokaryotes, the essential genes required for growth and reproduction are carried on one long, circular chromosome
Where do prokaryotes contain smaller DNA genes
Some prokaryotes carry smaller genes in circular DNA molecules called plasmids
What do plasmids help do
Plasmids help prokaryotes better survive in their environment
How does the DNA found in each cell of an organism compare
They are identical
How long is DNA when unraveled
It is taller than you (6ft)
What allows chromosomes to be tightly packaged
Special packing proteins associated with DNA allow chromosomes to be packaged tightly into the nucleus
Double helix Definition
In biology, the term used to describe the shape of DNA; helix means spiral, and the two sides of the DNA strand make it a double spiral
What is every molecule of DNA made up of
Nucleotides
Nucleotide Definition
A subunit of a nucleic acid molecule that is made up of sugar, a phosphate, and a nitrogenous base
DNA has 4 different types of nucleotides that are all identical except for the base. What are they
These four nucleotides are adenine (A), thymine (T), guanine (G), and cytosine (C)
How is DNA’s structure formed
DNA’s unique structure is formed by linking large numbers of individual nucleotides
What does a DNA molecule consist of
A DNA molecule consists of two strands of individual nucleotides linked together and twisted to form a double helix
Is the DNA sequence readable
The sequence of the nucleotide base pairs (DNA sequence) represents a type of code to cells, though it is not easily readable in its original form
How do you make the DNA sequence easier to read
To make this code into a more readable format by cells, it is first transcribed into messenger RNA, or mRNA, and ultimately translated into a sequence of amino acids, making a protein
Transcription Definition
The synthesis of an RNA molecule using a DNA molecule for a template
RNA Definition
Ribonucleic acid; nucleic acid that uses the instructions stored in DNA to build proteins
Messenger RNA (mRNA) Definition
A type of RNA molecule with a complementary code to the part of the DNA molecule that codes for protein structure, and that carries that message from the DNA (in the nucleus) to the ribosome in the cytoplasm, where it determines the order of amino acids in the protein
Translation Definition
The synthesis of protein using the sequence of nucleotides in messenger RNA (mRNA) to determine the amino acid sequence of the protein
How are 3 base groups of DNA transcribed
Every group of 3 bases of the DNA, read from one end of the strand to another, is first transcribed into mRNA. This is accomplished by way of numerous enzymes within the nucleus
Protein Making Sequence
DNA to mRNA (via transcription) to amino acids (via translation) to protein
Where does transcription occur
In the nucleus of a cell
Where does translation occur
In the cytoplasm of the cell
Why are transcription and translation necessary
Transcription is necessary to convert DNA code into readable mRNA sequences. Translation is necessary to translate mRNA sequences into amino acids
How is mRNA created
mRNA is created by copying one side of the DNA double helix
What is the main difference between DNA and RNA
The main difference between DNA and RNA is that instead of thymine as one of its four bases, RNA has uracil (U), which will also pair up with adenine
What are the complementary bases in RNA
Uracil and Adenine; Cytosine and Guanine
What are the four different types of nucleotide bases in RNA
Uracil (U), Adenine (A), Cytosine (C), and Guanine (G)
Due to DNA’s and RNA’S similar structure, what can RNA do
Because the structure of RNA is so much like the structure of DNA, it can act as one side of DNA to copy information from the DNA code
The mRNA is created along segments of a DNA molecule called what
Genes
How can RNA copy DNA
RNA can copy DNA because the complementary bases can pair with each other
What is the base-pairing rule for DNA
Adenine pairs with thymine, and guanine pairs with cytosine
What is the base-pairing rule for RNA
Uracil pairs with adenine, and guanine pairs with cytosine
What happens after mRNA copies the information from the gene
After the mRNA copies the information from the DNA segment (the gene), it detaches from the DNA and moves out of the nucleus. Then the RNA works to turn the instructions into protein
What are the three types of RNA that have roles in making proteins
mRNA, tRNA, rRNA
What does mRNA do
Messenger RNA, or mRNA, carries a message from the DNA to ribosomes in the cytoplasm where the message will be “read”. The message is a sequence of amino acids to make the protein
What does tRNA do
Transfer RNA, or tRNA, carries the amino acids that will make up the protein
What does rRNA do
Ribosomal RNA, of rRNA, makes the proteins in the ribosome of the cell
Which process creates sex cells
Meiosis
What is tRNA (Structure)
tRNA is RNA with folded structures containing loops to recognize and decode mRNA
What is rRNA
rRNA is a structural component of a ribosome
Which cell division process produces gametes
Meiosis
At the end of meiosis, how many chromosomes does each daughter cell have
Meiosis produces daughter cells with half the number of chromosomes of the parent cell
Gametes Definition
A collective word for sex cells, eggs and sperm, or for any cell that combines with another to form a zygote
Zygote Definition
The cell that results from the fusion of two gametes
What is the first cell of a new individual
The zygote is the first cell of a new individual and contains the usual number of chromosomes
Diploid Definition
Having two of each type of chromosome, constituting pairs of homologous chromosomes with the same genes
What is the ending result of meiosis
At the end of meiosis, the parent cell will have produced four gametes, each with half the number of chromosomes as the parent. This is the haploid number, or 1n, number
Haploid Definition
Containing one chromosome of each type
What is the main difference between mitosis and meiosis
Their outcomes
What is the outcome of mitosis
Mitosis ends with two daughter cells that are identical to the parent cell
What is the outcome of meiosis
Meiosis ends with four daughter cells, each with half the genetic material of the parent cell, and each with a unique combination of genes
What do the gametes at the end of meiosis consist of
When gametes form at the end of meiosis, they carry randomly distributed alleles from the parent
Which two stages is meiosis divided into
Meiosis I and Meiosis ll
What happens during meiosis l
Homologous chromosomes separate
What happens during meiosis ll
Sister chromosomes separate
What happens before meiosis l
All chromosomes make copies of, or replicate, their DNA, but the replicated chromosomes (or chromosome pairs) remain attached to each other at their centromeres (Interphase)
What happens during meiosis l
1) Homologous chromosomes pairs line up side by side during metaphase l. Remember that except for different sex chromosomes, homologous chromosomes contain the same set of genes
2) At the end of meiosis l, each replicated chromosome separates from its pair and moves to one end of the cell. The other chromosome of the pair moves to the other end and two new cells form
3) Each of the 2 cells formed at the end of meiosis l contains a complete set of chromosomes
What happens during meiosis ll
1) The replicated chromosomes (or chromatid pairs) in each of the two cells line up along the middle of the cell, and then the chromatids separate at the centromere during anaphase ll. These separated chromatids are now called chromosomes
2) Each chromosome moves to the end of the cell, and the cell divides
3) Four gametes result, each with half the chromosome number of the parent cell (1 chromosome from each original chromosome pair)
How do cells divide in meiosis
In meiosis, each of the two daughter cells from the first division divides into two new cells in the second division, making four cells
What cell division process creates genetic variation from one individual to another
Meiosis
What is the order of the phases in meiosis
Prophase, metaphase, anaphase, telophase, cytokinesis
What happens in prophase l
Chromosomes coil and become more compact; spindle starts to form
What happens in metaphase l
Chromosome pairs line up in the middle of the cell
What happens in anaphase l
The chromosome pairs separate and go to opposite sides of the cell
What happens in Telophase and Cytokinesis l
The cell and its contents begin to divide in the middle, with half of the chromosomes going to each new cell
What happens in prophase ll
Chromosomes coil and become more compact; spindle starts to form
What happens in metaphase ll
Chromosomes line up in the middle of the cell
What happens in anaphase ll
Chromosomes split and begin to move apart
What happens in Telophase and Cytokinesis ll
Chromosomes reach opposite sides of the cell, unravel, and incorporate into 2 new nuclei
What produces genetic diversity
Meiosis
What is similar about meiosis and mitosis: Stages
Both meiosis and mitosis have phases with the same names, taking place in the same order
What is similar about meiosis and mitosis: Chromosomes
Both meiosis and mitosis involve the chromosomes inside your cells
What is different about meiosis and mitosis: Results
Mitosis results in two genetically identical diploid cells, and meiosis in four genetically different haploid cells. Meiosis also has more steps
What is similar about meiosis and mitosis: Preparation and Division
In both mitosis and meiosis, chromosomes are copied, forming chromosome pairs, or chromatids. Chromatids are joined together at the centromere
What is different about meiosis and mitosis: Phases
Mitosis has fewer phases because it is simply copying the genetic material, which takes only one cycle. However, meiosis requires 2 cycles of cell division
What happen in the 2 cycles of meiosis
The 1st cycle is the copying of genetic material, and the second cycle is the separating of genetic information so that each cell has half the number of chromosomes as a regular cell
Why do all multi-celled organisms need cell division
To grow and heal
Our bodies came from one cell that kept dividing. Why do you think they need these new cells?
They need to create new cells to heal, grow, and metabolize
Why is meiosis important to a species
It produces genetic diversity, which helps health
Which is more important: Meiosis or Mitosis
They are equally important
What type of cells does Mitosis include
Two diploid cells
Each gene specifies for what
Each gene specifies for the production of certain proteins, which in turn, cause certain traits to be expressed
What is a nucleotides
A DNA molecule
What does a nucleotide consist of
A phosphate, sugar, and a nitrogen containing base
What forms the DNA double-helix
The 4 nucleotides pair with each other to join the two strands of DNA, forming the ladder-like double helix
What happens when DNA replicates
When DNA replicates, it unwinds and a copy is made of each DNA strand
Mutation Definition
Any change in a gene or a chromosome
What is a mutation
A mutation is any change in DNA or RNA
How do the effects of mutations vary
Mutations can be helpful, harmful, or have no effect at all
What are some causes of mutations
Chemicals, viruses, and radiation sometimes cause mutations
How does meiosis contribute to mutations
Mistakes during the meiosis process are another cause of mutations
What is the bodies attempt to stop and identify mutations
Within the cell, specific proteins are able to find and repair many mutations. These proteins do not always find the mutations, however
What happens to a mutation that remains undetected
A mutation that remains undetected in the cell may be passed on when the cell divides. If mutation occurs in an egg or sperm cell, the mutation may be passed on to the offspring
What do scientists believe about mutations
Scientists believe mutations play an important role in how species change over time
How did avian flu, or bird flu, mutate
The virus that contains avian flu, or bird flu, mutates so that it is more resistant to treatment
How does smoking cause mutation
Smoking causes mutation in lung cells, causing lung cancer
What are the four bases in DNA
Adenine, guanine, cytosine, thymine
What do the sequence of bases in RNA and DNA form
The sequence of the bases of DNA and RNA molecules form a code
How are genes and proteins related
Genes contain specific sequences that are transcribed as mRNA and translated to produce specific proteins. The sequence of genes determine the proteins produced
What can a change in a base in DNA and RNA affect the gene
A change in one base of the sequence may affect the entire code of the gene
True or False: All mutations occur in one or two nucleotides
False; Not all mutations occur in one or two nucleotides
How major are small-scale mutations
Small-scale mutations are often repaired or reversed by certain processes within the cell
How major are large-scale mutations
Large-scale mutations are serious
What happens in large-scale mutations
In large-scale mutations, large sections of chromosomes are changed, or sections of a chromosome may be duplicated. This may result in extra copies of a gene that may “amplify” the effects of that gene. Conversely, large sections of a chromosome may be deleted, resulting in the loss of entire genes
What do large-scale mutations change
They alter internal and external appearances
True or False: Changes in traits of a species is caused by natural selection
Ture
Natural Selection Definition
Process by which organisms with certain traits survive to reproduce and pass on those traits to their offspring
Selective Breeding Definition
The process of breeding organisms with the most desirable traits
How long does it take a desired trait in selective breeding to appear
Selective breeding takes many generations to produce the desired trait
In selective breeding, how long does it take to achieve the desired gene combination
Since many genes are being shuffled in each breeding experiment, it can take many generations to achieve the desired combination of genes
Genetic Engineering Definition
The manipulation of DNA to produce molecules or organisms with new properties
What hormone does genetic engineering help humans produce
Insulin
What is insulin
Insulin is a hormone that helps the body use and store sugar
People that can not produce insulin posses which disease
Diabetes
How did insulin used to be extracted before genetic engineering
Insulin used to be extracted from cows and pigs, but this process often resulted in extracts with impurities and caused immune reactions in people with diabetes since the extracted protein was not human
What did Frederick Sanger do in 1955
In 1955, Frederick Sanger determined the amino acid sequence of human insulin. For this work, he received the 1958 Nobel prize in chemistry. This sequence was used to genetically engineer bacteria to produce large amounts of pure human insulin
Insulin is an example of what
Insulin is one of the first examples of a drug produced using genetic engineering techniques to make safer, more efficient quantities
How do individuals with diabetes use insulin
Individuals with diabetes use genetically engineered insulin engineered insulin to control their disease without the side effects caused by cow or pig insulin
Exactly how is genetically engineered insulin produced
Scientists insert the human gene for producing insulin into the chromosome of a bacterium. This bacterium now has the genetic instructions for making insulin. As the bacterial cell produces in the lab, each cell produces human insulin
How are many drugs and vaccines being made by now
They are now produced using genetic engineering
How are genetically engineered drugs and vaccines safer
Genetically engineered drugs and vaccines are safer and better than ones with dead bodies or microorganisms since their based on a human protein
How do organisms change
Organisms change through natural selection, selective breeding, and genetic engineering
Why do crops fail to thrive
Crops fail to thrive due to pests, weed competition, poor soil, and weather conditions
How can genetic engineering help plants and other animals
Genetic engineering can produce pest-resistant crops, frost-resistant crops, crops that can stand salty soil, foods that can bring vitamins or vaccines to parts of the world with no modern medicine, fish that glow under ultraviolet light, and pigs with less saturated fat
When is genetic engineering a possible threat
Some genetic engineering technologies produce organisms that interact with the environment. This could cause problems that might be difficult to contain
What may help in the future if a gene has a defect
When a gene has a defect, a genetic engineering technique known as gene therapy may help in the future
Gene Therapy Definition
A process used to treat or correct a genetic disease or disorder by replacing missing or defective genes
What happens in one type of gene therapy
In one type of gene therapy, cells with defective genes are replaced with cells with normal genes
What is the goal of gene therapy
To restore the normal function of the cells
What is the risk of gene therapy
Since gene therapy is still a new procedure, it can be risky and may not be effective
What are the two methods of changing genes
Genetic engineering and gene therapy
