Science 7 ch 4
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Science 7 ch 4
Science 7th grade genetics
Science 7th grade ch 4 genetics
Passing of physical characteristics from parent to offspring
Each different characteristics
The scientific study of heredity
When a new organism begins to form when the egg and sperm join
An organism that is the offspring of many generations that have the same trait
The factors that control a trait
The different form of a gene
One whose traits always show up in the organism when the allele is present
A trait that is hidden when the dominant allele is present-
Organism who have 2 different alleles for a trait
-What were the results of Mendel's experiments or crosses?
When he crossed purebred plants for stem height, all were tall
When he crossed hybrid plants for stem height, 3/4 were tall and 1/4 were short
What controls the inheritance of traits in organisms
A number that describes how likely it is that an event will occur
A chart that shows all possible combinations of alleles that can result from a genetic cross
The physical appearance or visible traits
The genetic makeup of or allele combination
An organism that has 2 identical alleles
An organism that has 2 different alleles
The alleles are neither dominant nor recessive and both alleles are shown in the offspring.
What is probability and how does it help explain the results of genetic crosses?
The process by which the number of chromosomes are reduced by half to form sex cells
Has to do with the egg and sperm
- Half the number of body cells-Diploid- The total number of body cells
The total number of body cells
What events occur during meiosis?
How is meiosis similar to mitosis?
They both result in separation of existing cells into new ones
How is meiosis different from mitosis?
Meosis is responsible for reproducing gametes
Meisos involves not one but 2 cell divisions
cells that undergo meiosis reduce their number of chromosomes by half
Germ cells are haploid, contain one complete set of chromosomes
Any cell forming the body of an organism except germ cells
How is mitosis different from meiosis?
Mitosis is responsible for reproducing somatic cellsMitosis involves one cell divisionSomatic cells are diploidCells that undergo mitosis duplicate their chromosomes
Sex cells - sperm & egg
How many pairs of chromosomes do human cells contain
What Sutton observed about chromosome number
grasshopper sex cells have half the number of chromosomes as body cells
grasshopper body cells and sex cells have the same number of chromosomes
Chromosome theory of inheritance?
Genes are carried from parents to their offspring on chromosomes
A number that describes how likely it is that an event will occur?