study guide for unit 2 Flashcards
genotype
The actual genetic make up of an organism that it gained from its parents
phenotype
The way an organism looks based on its genetics/genotype (physical appearance)
Gregor Mendel
father of genetics. He cross pollinated, two pea plants, purple flower with white flower. first generation got only purple flowers produced, second generation, one white pea plant was produced. *the proved dominant and recessive alleles.
how many alleles is hh
1
how many alleles is hs
2
what is mendels law of dominance?
two choices for each trait, and if both jeans are present, one expresses over the expense of the other.
what is mendels law of parental equivalence?
The sex of the parent does not determine if or if not, the dominant trait is expressed.
what is the gene locus?
The place on a chromosome, where a gene is found.
what is a carrier
A person with an inactive trait that can pass on to future generations.
incomplete dominance?
One allele will not overpower the other, instead, they’ll mix.
Example: red + white flower = pink flower
co dominance?
One allele will not overpower the other, instead both characteristics are displayed in their complete form.
Example: brown and white cow = white cow with brown dots
polygenic inheritance?
The inheritance of traits that are influenced by multiple genes.
example; eye colour is influenced by 15 genes
lethal alleles?
Versions of genes that can cause severe health problems, or even death.
(these alleles are often recessive)
linked genes?
genes that are located close to each other on the same chromosome, because they are so close together they tend to be inherited together more often than not.
Example: red hair and freckles.
chromosome?
each chromosome is made of protein in a single molecule of DNA. Chromosomes carry the genes which responsible for your hereditary characteristics.
23 pairs, 46 chromosomes in humans.
karyotype?
shows the number and appearance of chromosomes in an organism.
what is mitosis?
A form of eukaryotic cell division that produces two daughter cells with the same genetic components as a parent. One diploid parent cell (2n) = 2 diploid daughter cells (2n)
do sex cells undergo mitosis OR meiosis?
meiosis ONLY
what are the steps of IPMAT mitosis
INTERphase- DNA replication (chromosomes duplicate. happens before mitosis
PROphase- chromosomes condense; nucleus starts to breakdown, allowing chromosomes to move freely.
METAphase- MIDDLE stage; chromosomes align at the centre of the cell.
ANAphase- AWAY; spindle pulls sister chromatids to opposite poles.
TELOphase- TWO(2) cells; the cytoplasm begins to split in half, spindles disappear & nucleus begins to reform.
what is cytokinesis?
Cell divides, two daughter cells are formed
what is meiosis?
A form of eucaryotic cell division that produces 4 daughters cells with HALF genetic information as a parent cells. Sex cells (ova & sperm) divide using the process of meiosis. One diploid parent cell (2n) = 4 haploid daughter cells (n)
what are the steps of meiosis 1?
INTERphase 1- the state of the cell before meiosis.
PROphase 1- chromosomes, replicate, homologous chromosomes pair together.
METAphase 1- chromosomes align at the centre of the cell, homologs paired.
ANAphase 1-spindles pull homologous pairs opposite poles.
TELOphase 1-spindle disappear, nucleus starts, reforming, cell division begins.
what is the importance of meiosis 2?
two haploid daughter cells are formed (3 chromosomes each with 2 chromatids) now only chromosomes remain (no homologous pairs)
what are the steps of meiosis 2?
PMAT (no interphase in meiosis 2)
PROphase 2- nucleus, dissolves, spindles form.
METAphase 2- spindles attach and centre chromosomes in the middle of the cell.
ANAphase 2- spindles pull chromosomes apart, and drag them to opposite poles.
TELOphase 2- nucleus, reforms, cells divide, and four haploid daughter cells are formed.