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7thGr-Sci-Heredity
7th Grade Science Heredity & Genetics Test
Question | Answer |
---|---|
Genetics | The study of how traits are inherited. (Example: Blue-eyed mom x blue-eyed dad = blue-eyed baby) |
Chromosome | Structure in a cell's nucleus that contains genetic material (DNA) |
Trait | A distinguishing characteristic or quality (Example: eye color, face shape, etc.) |
Heredity | The passing of traits from parents to offspring. (Example: AA x aa = Aa only) |
Genotype | The genetic makeup of an organism - how its genes look! (Example: AA, Aa or aa) |
Phenotype | The physical appearance of an organism due to the genes it has. (Example: Tall or short, Blonde or brunette, etc.) |
Dominant | A genetic trait that is expressed as long as there is one allele present. (Example: AA or Aa - the 'A' trait is expressed.) |
Recessive | A genetic trait that is expressed only when there are two alleles present. (Example: aa - the 'a' trait is expressed.) |
Homozygous (or purebred) | Having two identical alleles for a trait. (Example: AA or aa) |
True breeding | An individual homozygous for a trait - can only pass one of the forms of the gene to its offspring. (Example: AA can only pass 'A' to its offspring aa can only pass 'a' to its offspring.) |
Heterozygous (or hybrid) | Having two different alleles for a trait. (Example: Aa) |
Hybrid | An individual heterozygous for a trait - can pass on either form of the allele. (Example: Aa can pass either 'A' or 'a' to its offspring.) |
Types of asexual reproduction | binary fission (splitting in two)(ex: bacteria), budding (ex: yeast, hydra), regeneration (ex: planarian, starfish), vegetative propagation (ex: onion, strawberry) budding |
Nuclueus | Control center of the cell |
DNA | genetic material which is contained in the nucleus. |
Chromosomes | Human body cells contain 23 sets made of DNA. |
How many genes are in each chromosome? | Hundreds to thousands. |
Genes | Specific sections of DNA that code for traits. |
Allele | Each trait has 2 parts. Each part is called this. They are classified as either dominant or recessive. |
Dominant allele | Covers up the alleles that are not as strong. |
Recessive allele | Weaker alleles. |