What are the three stages of interphase?
G1 Phase (Gap 1) : The cell grows,and prepares for DNA replication.
S Phase (Synthesis) : Dna replication
G2 Phase (Gap 2) : The cell continues to grow and gets ready for division, checking for any errors in DNA. getting ready for mitosis
What are the two main reasons why cells need to replicate (as in mitosis)?
Growth : Cells need to multiply to help organisms grow and repair tissues.
Replacement : when you shave and sunburn
Describe briefly what happens in anaphase.
During anaphase, the paired chromosomes (sister chromatids) are pulled apart and move to opposite sides of the cell. Anaphase for away apart from each other
What are the two main functions of apoptosis?
Remove Damaged Cells : It helps get rid of cells that are damaged or no longer needed.
Development : It shapes structures during development by removing excess cells.
What is cancer?
Uncontrolled cell growth
How do cancer cells differ from normal cells?
They look different : more round and squishy
hat are the three types of RNA? Explain the function of each type.
mRNA (Messenger RNA) : Carries instructions from DNA to the ribosome to make proteins.
tRNA (Transfer RNA) : Brings amino acids to the ribosome during protein synthesis.
rRNA (Ribosomal RNA) : Makes up the structure of ribosomes, where proteins are made.
Explain complementarity in DNA and why it occurs.
Complementarity means that specific bases pair together: adenine (A) with thymine (T), and cytosine (C) with guanine (G). This occurs because of chemical bonds that form between the bases, ensuring accurate DNA copying.
What subunits make up the DNA nucleotides?
DNA nucleotides are made up of:
A phosphate group
A sugar (deoxyribose)
A nitrogen base : Purines (A, G) and Pyrimidines (C, T).
What are the two most important features of meiosis?
Reduces amount of genetic material in gametes / Reduces Chromosome Number : Meiosis creates gametes with half the number of chromosomes.
Produces gametes that all differ from each other with respect to combinations of alleles they carry / Increases Genetic Variation : It mixes genes through crossing over an independent assortment.
Compare and contrast mitosis and meiosis.
Similarities :
Both are ways cells divide.
Both involve DNA replication.
Both happen in eukaryotic cells.
Differences:
Mitosis produces two identical cells; meiosis produces four unique cells.
Mitosis has one division; meiosis has two.
Mitosis does not involve crossing over; meiosis does.
What is synapsis in meiosis?
Synapsis is when homologous chromosomes pair up during meiosis, allowing for crossing over and genetic mixing.
What is the important outcome of meiosis?
Meiosis produces gametes (sperm and eggs) with half the number of chromosomes, leading to genetic diversity.
What is random fertilization?
Random fertilization is the process where any sperm can fertilize any egg, increasing genetic diversity in offspring.
What are the advantages of sexual reproduction?
Genetic Diversity: Offspring have different traits, which can help them survive in changing environments.
Disease Resistance: A varied gene pool can protect a population against diseases.
Adaptation: More genetic variation allows for better adaptations to new challenges.
What are the advantages and disadvantages of asexual reproduction?
Advantages:
Quick Growth: Can produce many offspring quickly.
Less Energy: No need to find a mate, which saves time.
Stable Conditions: If the environment is good, identical offspring will likely thrive.
Disadvantages:
No Variation: Offspring are identical, which can be bad if conditions change.
Mutation Accumulation: Harmful mutations can build up over generations.
List five types of asexual reproduction.
Budding: A new organism grows on the parent and eventually breaks off.
Fragmentation: An organism breaks into pieces, each capable of becoming a new individual.
Binary Fission: One cell divides into two identical cells, common in bacteria.
Vegetative Propagation: New plants grow from parts of the parent plant, like roots or stems.
Parthenogenesis: Offspring develops from unfertilized eggs.
Fragment/ regeneration :
Describe budding.
Budding is when a small part of a parent organism grows into a new individual and eventually separates.
Describe fragmentation.
Fragmentation is when an organism breaks into pieces, and each piece can grow into a new organism.
What is a nondisjunction?
Nondisjunction is when chromosomes fail to separate properly during cell division, leading to an abnormal number of chromosomes.
What is the definition of heredity?
Heredity is the passing of traits from parents to offspring through genes.
What are single-gene traits? Give at least one example.
Single-gene traits are traits controlled by one gene, like the ability to roll one’s tongue.
Why did Mendel choose the garden pea for his experimental system?
Mendel chose garden peas because they have clear traits, are easy to grow, and can be cross-pollinated.
What is the difference between phenotype and genotype?
Phenotype: The visible traits of an organism.
Genotype: The genetic makeup that determines those traits.
What is the difference between dominant and recessive alleles?
Dominant Alleles: Traits that show up even if only one copy is present (e.g., T for tall).
Recessive Alleles: Traits that only show up if two copies are present (e.g., t for short).
What is a punnett square and what is it used for?
A Punnett square is a chart used to predict the possible genetic outcomes of a cross between two organisms.
What is Mendel’s Law of Segregation?
This law states that during gamete formation, the two alleles for a trait separate, so each gamete gets only one allele.
What are the five reasons why some traits do not show Mendelian inheritance?
Continuous Variation : All sorts of variations height
Pleiotropic effects :
Incomplete Dominance: Heterozygous traits blend together (e.g., pink flowers from red and white parents).
Environmental Influences: External factors can affect how genes are expressed. Artec fox coat based on temp
Codominance: Both traits are fully expressed (e.g., AB blood type).
Multiple Alleles: More than two alleles exist for a gene (e.g., blood types A, B, O).
Polygenic Inheritance: Traits are controlled by multiple genes (e.g., skin color).
What is a sex-linked trait?
A sex-linked trait is a trait associated with a gene found on a sex chromosome, often showing different patterns of inheritance in males and females.
What are x-linked disorders and give an example.
X-linked disorders are conditions caused by mutations on the X chromosome. An example is hemophilia, a bleeding disorder.
Define autosome, recessive disorder, and autosomal recessive disorder.
Autosome: A non-sex chromosome.
Recessive Disorder: A genetic condition that only shows if two copies of the recessive allele are present.
Autosomal Recessive Disorder: A recessive dysfunction related to an autosome
What is the difference between polyploidy and aneuploidy?
Polyploidy: Having more than two sets of chromosomes (e.g., triploidy).
Aneuploidy: Having an abnormal number of chromosomes (too many or too few).
What are the two important features of DNA?
Double Helix:The structure of DNA is twisted like a ladder, which helps store information.
Base Pairing: Specific pairing of bases ensures accurate copying and function.
What is a genome?
A genome is the complete set of genetic material in an organism.
What is the definition of a gene?
A gene is a segment of DNA that contains the instructions for making a specific protein.
What is an intron?
An intron is a non-coding section of a gene that is removed during RNA processing.
What is a mutation?
A mutation is a change in the DNA sequence that can affect how genes function.
What is the difference between a point-shift and a frame-shift mutation?
Point Mutation: A single nucleotide change in the DNA sequence affecting only one amino acid
Frame-Shift Mutation: Insertion or deletion of nucleotides that shifts the reading frame, altering the entire protein.
What is the difference between a transversion and a transition? And which is more common?
Transition : A change from one purine to another (A ↔ G) or one pyrimidine to another pyrimidine (C ↔ T).
Transversion : A change from a purine to a pyrimidine or vice versa. Transitions are more common.
What is the difference between a nonsense and a missense mutation?
Nonsense Mutation: Changes a codon to a stop codon, leading to a truncated protein.
Missense Mutation: Changes a codon to a different amino acid, potentially altering protein function.
What is the difference between a conservative and a non-conservative mutation?
Conservative Mutation: Changes an amino acid to another with similar properties.
Non-Conservative Mutation: Changes an amino acid to one with different properties, which can affect protein function.
How does RNA differ from DNA?
Structure: RNA is single-stranded; DNA is double-stranded.
Sugar: RNA has ribose; DNA has deoxyribose.
Bases: RNA uses uracil (U) instead of thymine (T).
What is necessary for translation to occur?
For translation, you need mRNA, tRNA, ribosomes, and amino acids.
Briefly define transcription and translation.
Transcription: The process of making mRNA from DNA.
Translation: The process of making proteins from mRNA.
What is the definition of genetic engineering?
Genetic engineering is the manipulation of an organism's DNA to achieve desired traits.
What are restriction enzymes?
Restriction enzymes are proteins that cut DNA at specific sequences, used in genetic engineering.
What is PCR used for?
PCR (Polymerase Chain Reaction) is used to make millions of copies of a specific DNA segment.
What is cloning?
Cloning is creating a genetically identical copy of an organism or cell.
What is a transgenic organism?
A transgenic organism is one that has DNA from another species inserted into its genome.
Flashcard (19)
Studied by 4 people
Note