ZOOLOGY LEC REVIEW

• Alleles: are alternative forms of a gene and are found at the same place in chromosome.
• Homozygous: Genotypes with identical alleles
• Heterozygous: different alleles
• Crossing over: when chromosomes of the same type are lined up, parts of the chromosome can be switched.
• Independent assortment: genes are inherited independently of one another.
• Silent mutation: has no effect on the protein sequence
• Missense: results in an amino acid substitution.
• Nonsense: substitutes a stop codon for an amino acid
• Punnet square: used to check for probabilities in genetics.
• Pedigree analysis: Traits are traced through generations
• Autosomal dominant: getting one dominant allele from either parent will allow the trait to be expressed.
• Autosomal recessive: a specific trait will only be expressed if the individual was able to get one copy from each parent.
• Fertilization: the process in which sperm and egg fuse to form a zygote
• Blastula: a spherical layer of cells surrounding a fluid filled or yolk filled cavity (the blastocoel)
• Gastrulation: generates the three primary germ layers.
• Neurulation: marks the beginning of the process of organogenesis
• Cell differentiation: the process by which dividing cells change their functional and phenotypical type
• Totipotent: have the capacity to produce all adult cell types, can enter the germ line and have proven ability to self replicate.
• Pluripotent: capable of giving rise to several different cell types
• Multipotent: have the ability to differentiate into all cell types within one particular lineage
• Unipotent: capable of giving rise to only one cell type
• Stem cells: cells with the ability to develop into many different cell types
• Growth rate: determined by the balance between cell proliferation and cell death
• Ectoderm: epidermis, glands on skin, etc.
• Mesoderm: connective tissue proper, bone, cartilage
• Endoderm: lining of airways and digestive system
• Epithelial Tissue: sheet like tissue with one free surface, rests on basement membrane
• Connective tissue: forms a matrix beneath the epithelial layer, provide structural and mechanical support for other tissues
• Skeletal muscle: interacts with bone to produce movement and maintain posture
• Cardiac muscle: found only in the heart
• Smooth muscle: used to apply pressure to vessels and organs
• Nervous tissue: composed of neurons and supporting cells