Term
Genetics (def)
Heredity (def)
Variation (def) |
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Definition
Genetics - study of heredity and variation
Heredity - transmission of traits from one generation to the next
Variation - Demonstrate in the differences in appearance that offspring show from their parents |
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Term
Genes (def)
Gametes (rel)
Locus (def/rel) |
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Definition
Units of heredity, made up of segments of DNA
Genes are passed from parents to offspring through gametes (reproductive cells)
Locus is the specific gene's location on a certain chromosome |
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Term
Asexual reproduction (def)
Clone (def)
Sexual reproduction (def) |
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Definition
Asexual - A single parents produces genetically identical offspring through mitosis
Clone - a group of genetically identical individuals from a single parent
Sexual - Two parents give rise to offspring that have unique combinations of genes inherited from both parents |
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Term
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Definition
| Generation to generation sequence of stages in the reproductive history of an organism |
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Term
Sets of Chromosomes in Human Cells
(Somatic/Karyotype/Homologs) |
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Definition
Somatic cells (non-sex cells) have 23 pairs of chromosomes in each
A karyotype is an order display of the pairs
The two chromosomes in each pair are call homologous chromosomes
Homologous chromosomes are the same length and carry genes controlling the same traits |
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Term
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Definition
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Term
| Homologous Chromosomes (prop) |
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Definition
- Includes one chromosome from each parent
- The 46 chromosomes in a human cell are two sets of 23: one from mother and one from father
- Each member of the pair has its own genes for controlling each trait |
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Term
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Definition
The fertilized egg (union of egg and sperm)
Has one set of chromosomes from each parent
Produces somatic cells by mitosis and develops into an adult |
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Term
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Definition
Produces gametes, which are the only types of cells produced by meiosis
Results in one set of chromosomes in each gamete |
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Term
| The Variety of Sexual Life Cycles |
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Definition
Alteration of meiosis and fertilization common to all sexually reproducing organisms
Three types of sexual life cycles present |
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Term
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Definition
-Gametes undergo no further cell division until fertilization
-Are the only haploid cells in an animal |
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Term
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Definition
- Alternation generations
- Includes both diploid and haploid multicellular stages
- Sphorophyte (diploid) produces spores (haploid)
- Each spore grows by mitosis into a gametophyte |
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Term
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Definition
-Only diploid stage is a single-celled zygote, no multicellular diploid stage
-Produces haploid cells by meiosis
-Haploid cells reproduce with mitosis into multicellular haploid organism |
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Term
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Definition
Meiosis I - Homologous chromosomes separate, creates haploid cells
Meiosis II - Sister chromatids separate, essentially like mitosis,
Results in 4 haploid daughter cells |
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Term
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Definition
Prophase I
Metaphase I
Anaphase I
Telophase I |
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Term
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Definition
90% of meiosis time
- Chromosomes condense
- Synapsis occurs (homologous chromosomes pair up, aligned gene by gene)
- Crossing over (non-sister chromosomes exchange genes) at chiasmata |
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Term
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Definition
- Tetrads line up at metaphase plate
- Microtubules from one pole attach to the kinetochore
- Each chromosome pair on the tetrad attached to a different pole |
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Term
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Definition
- Pairs of homologous chromosomes separate
- Sister chromatids remain attached at centromere |
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Term
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Definition
| In the beginning of telophase I, each half of the cell has a haploid set of chromosomes; each chromosome still consists of two sister chromatids |
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Term
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Definition
- Essentially mitosis
- Sister chromatids are separated into different cells
- Results in 4 haploid cells, each is genetically distinct from each other and the parent cells |
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Term
| Mechanisms of genetic variation |
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Definition
Independent Assortment
Crossing Over
Random fertilization |
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Term
| The Evolutionary Significance of Genetic Variation Within Populations |
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Definition
- Natural selection results in the accumulation of genetic variations favored by the environment
- Sexual reproduction contributes to the genetic variation in a population, which originates from mutationsCopyright |
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