Genetics and evolution Flashcards
What is a gene?
A characteristic such as height in a person in a person due to a gene
What is an allele?
Each gene has two alleles, which is the different form of a characteristic (e.g. tall (T) or short(t))
what is genotype?
the type of genes (alleles) present. Each gene has two alleles - one from the father and one from the mother (T-dad, t-mum)
What is phenotype?
What it looks like
Who is Gregor Mendel and what did he do?
Gregor Mendel was an Austrian scientist, teacher, and Augustinian prelate who lived in the 1800s. He experimented on garden pea hybrids while living at a monastery and is known as the father of modern genetics.
What is the difference between a chromosome, gene and an allele
chromosomes are structures that carry genes, which are the fundamental units of heredity, while alleles are different forms of a gene that account for variations in specific traits or characteristics.
what is meiosis
a type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell, as in the production of gametes and plant spores.
what is mitosis
a type of cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent nucleus, typical of ordinary tissue growth.
what is the difference between mitosis and meiosis
There are two kinds of cell division: mitosis and meiosis. What’s the Difference? Mitosis produces two genetically identical “daughter” cells from a single “parent” cell, whereas meiosis produces four cells that are genetically unique from the parent and contain only half as much DNA.
How many chromosomes are in a healthy human?
46
How many chromosomes in sex cells in humans?
23
what are the steps of dna replication?
the opening of the double helix and separation of the DNA strands, the priming of the template strand, and the assembly of the new DNA segment
Why is DNA replication important
Cells must replicate their DNA before they can divide. This ensures that each daughter cell gets a copy of the genome, and therefore, successful inheritance of genetic traits. DNA replication is an essential process and the basic mechanism is conserved in all organisms.
What does DNA stand for?
deoxyribonucleic acid
How does DNA mutate?
Mutations result either from errors in DNA replication or from the damaging effects of mutagens, such as chemicals and radiation, which react with DNA and change the structures of individual nucleotides. All cells possess DNA-repair enzymes that attempt to minimize the number of mutations that occur
Define evolution
Evolution is a process of gradual change that takes place over many generations, during which species of animals, plants, or insects slowly change some of their physical characteristics.
How does evolution work?
These changes are produced at the genetic level as organisms’ genes mutate and/or recombine in different ways during reproduction and are passed on to future generations.
Outline the Darwin-Wallace Theory of Evolution by Natural Selection
Darwin and Wallace both realized that if an animal has some trait that helps it to withstand the elements or to breed more successfully, it may leave more offspring behind than others. On average, the trait will become more common in the following generation, and the generation after that.
What is a fossil?
the remains or impression of a prehistoric plant or animal embedded in rock and preserved in petrified form.
How do fossils form?
when a living organism dies and is quickly buried by sediment. Soft tissues often decompose, leaving only the hard bones or shells behind. After the organism has been buried, more sediment, volcanic ash or lava can build up over the top of the buried organism and eventually all the layers harden into rock
what is a decomposer
an organism, especially a soil bacterium, fungus, or invertebrate, that decomposes organic material. Decomposers are organisms that break down dead or decaying organisms; they carry out decomposition, a process possible by only certain kingdoms, such as fungi
