AGA: Genetics and Heredity

A unit of protoplasmic material with distinct structures.

• Organism
• Cell
• Organ
• Tissue

Components of a cell that determine the characteristics of iving things.

• Genes: DNA, RNA, and proteins

  (genetics)

• Cell membrane, cytoplasm, and nucleus
• Mitochondria, ribosomes, and lysosomes
• Lipids, carbohydrates, and vitamins

The physical appearance of an individual is determined by its

• phenotype

• genotype

• chromosome

• allele

What do you call a group of animals with similar characteristices and that can pass those characteristics on to their offspring?

• family
• breed

• herd

• trait

The genetic makeup of an organism.

• Genotype
• Chromosome
• Allele
• Phenotype

Pairs of genes that are alike are called

• alleles

• centromeres

• chromosomes

• DNA

A genetic characteristic that can be expressed when just one allele with that characteristic is present.

• Incomplete dominant allele
• Codominant allele
• Dominant allele
• Recessive allele

An allele that only expresses its trait when two copies are present, one from each parent.

• recessive allele
• heterozygous allele
• homozygous allele
• dominant allele

In agriculture, the area that most often deals with genetics is when we breed plants and animals for specific traits, such as higher milk production or bigger kernels of corn.

When we choose specific parents to get the desired characteristic in their offspring, it is called:

• hybridization
• selective breeding
• cross-pollination
• genetic modification

Selective breeding for specific traits happens over MANY generations.

For example, how long might it take to breed a new variety of grass that can resist changes in an individual pest, like grasshoppers?

• 8 to 11 years

• 3 to 4 years
• 15 to 20 years
• 1 to 2 years