Inheritance Flashcards
What are the two types of reproduction
Asexual and sexual reproduction
Define heredity
The passing of traits from parents to offspring
Asexual reproduction
“Clone” A single individual is the sole parent and passes copies of all it’s jeans to its offspring
What is sexual reproduction
Two parents giving rise to offspring that are unique combination of jeans
Where is all this information for all the seriation stored
Genes
What is a gene
A segment of DNA
What determines genetic traits
One or more genes
Genes code for the production of particular
Proteins
Proteins express
The characteristic of the genes
Nucleic acid store genetic information in chromosomes which are passed from _____ to ______ during reproduction
Parents
Offspring
Genes are segments of
DNA located on are chromosomes
What type of organism is DNA one circular chromosome
Prokaryotic
In what organism is DNA packaged into the chromosomes in the nucleus
Eukaryotic
Duplicated chromosomes are called
Sister chromatids
Sister chromatids are held together by the
Centromere
In interphase the DNA is uncoil and is called
Chromatin
How many chromosomes to humans have
46
What are the first 22 pairs of the human chromosomes called
Autosomes
What are the last pair of the human chromosomes called
The sex chromosomes
What do the sex chromosomes determine
The organisms gender
What are homologous chromosomes
A pair of chromosomes (maternal and paternal) similar in size and shape
What do homologies chromosomes carry
They carry genes controlling the same inherited traits
What are alleles
Different forms of the genes that control the same inherited traits
What is fertilization
To pass genes from mother to father gametes must fused together in the process called fertilization
Define zygote
The fertilized cell becomes a new, unique organism called a zygote
Each gamete (egg or sperm) has only a
Single chromosome from each homologous pair (haploid chromosome number)
Zygote has
One of each pair of homologous chromosomes (one from mom one from dad) or the diploid chromosome number
What is the type of reproduction division that produces genetically different gametes
Meiosis
What happensin interface of meiosis 1
G1: cell growth
S: DNA replication
G2: organelles replicate
Happens in prophase of meiosis 1
Homologous chromosomes pair and forms a tetrad
Chromatin condenses to form chromosomes
Spindle fibers form and nuclear membrane dissolves
Crossing over occurs
What is crossing over
Shuffles genome of homologous chromosomes (exchanges genetic information)
What happens in metaphase of meiosis 1
Spindle fibers attached to center mirrors and tetrads lineup (metaphase plate)
Maternal and paternal homologous chromosomes line up randomly
What happens in anaphase of meiosis 1
Homologous chromosomes separate to opposite poles
Sister chromatids remain attached at the centromere’s
What happens in telophase of meiosis one
Nuclear envelope reassemble
Spindle fibers disappear
Cytokinesis divides the two cells into haploid cells
What occurs in metaphase of meiosis 2
Same as metaphase in meiosis one
What occurs in anaphase of meiosis two
Same as meiosis one
Occurs in telophase of meiosis two
Same as to telophase in meiosis one
What is nondisjunction
Failure of homologous chromosomes or sister chromatids to separate properly and cell division
What are at least six differences of mitosis and meiosis
Number of divisions: Mitosis 1 mitosis 2
of daughter cells: mitosis (2) meiosis (4)
Geneticly identical? Mitosis (yes) meiosis no)
Chromosome #: mitosis(same as parent. Meiosis (half of parent)
Where: mitosis(somatic cells) meiosis: sex cells
When: mitosis(throughout life) meiosis(at sexual maturity)p
What are the three sources of genetic variation that come from meiosis
- Crossing over
- Independent assortment of homologous chromosomes
- Random fertilization of sperm and egg
