MOD 5 Flashcards
(35 cards)
Sexual Reproduction (ad/dis)
reproduction involving a male and female sex. Offspring will inherit unique combination of genes. Male and female must encounter each other for reproduction to occur.
Asexual Reproduction (ad/dis)
reproduction involving no sexes, and instead self-production. Produces large amounts of offspring quickly to take advantage of the environment. Less genetic variation as there is less variation in the population.
DNA replication
DNA replication is the process by which the double stranded DNA molecule is unzipped by enzymes, and free nucleotides bind to each of the exposed backbones to create two identical DNA molecules.
Helicase
Helicase responsible for the unzipping of the original DNA molecule in DNA replication.
DNA polymerase
DNA polymerase in the presence of the free nucleotides, will attract them in DNA replication.
Leading Strand
The leading strand represents the replicated molecule that moves in the direction of the replication fork and is continuously synthesised. (5-3 primer sequence).
Lagging Strand
The lagging strand is the original strand which moves in the opposite direction of the replication fork and is discontinuously synthesised through Okazaki (short) fragments. (5-3 primer sequence).
Genotype
A person’s genotype is their unique sequence of DNA.
Phenotype
Phenotype refers to an individual’s observable traits, such as height, eye colour and blood type.
Allele
the word that we use to describe the alternative form or versions of a gene.
Autosomal
means that the gene in question is located on one of the numbered, or non-sex, chromosomes. (no X or Y)
Recessive
Refers to a trait that is expressed only when genotype is homozygous; a trait that tends to be masked by other inherited traits.
Dominant
Refers to a trait that is expressed when the genotype is homozygous or heterozygous; trait is never masked by other inherited traits.
Homozygous
having two identical alleles of a particular gene or genes.
heterozygous
having two different alleles of a particular gene or genes.
Sex-Linked
Sex-linked, as related to genetics, refers to characteristics (or traits) that are influenced by genes carried on the sex chromosomes. (is X or Y)
Gamete
a mature haploid male or female germ cell which is able to unite with another of the opposite sex in sexual reproduction to form a zygote.
Mitosis
begins with two homologous chromosomes which is one chromosome from each parent (interphase). the pair then duplicates, becoming sister chromatids (prophase) which is followed by spindle fibres pulling each chromatid to a side of the cell (metaphase). the chromatids then seperate (anaphase), and produce two new cells each with two homologous chromosomes in them, one from each parent (telophase/cytokinesis).
Meiosis 1
begins with 4 homologous pairs of chromosomes in one cell (prophase). Homologous chromosomes line up at the metaphase plate (metaphase). Homologues seperate to the opposite end of the cell after exchanging fragments (anaphase). two new cells form with two homologous pairs of chromosomes in each, all with non-identical sister chromatids (telophase/cytokinesis).
Meiosis 2
chromosomes condense (prophase). Homologous pairs line up at metaphase plate (metaphase). Sister chromatids seperate to the ends of the cell (4 in each cell) (anaphase). Each cell separates creating 4 cells, each with two chromosomes (telophase/cytokinesis).
Phosphate Backbone
A phosphate backbone is the portion of the DNA double helix that provides structural support to the molecule.
Deoxyribose Sugar
Deoxyribose is a key building block of DNA. Its chemical structure allows for the replication of cells in DNA’s double helix configuration.
Eukaryotic
eukaryote, any cell or organism that possesses a clearly defined nucleus.
Prokaryotic
Prokaryote, any organism that lacks a distinct nucleus and other organelles due to the absence of internal membranes.