Unit 5: Heredity Flashcards
meiosis
process by which gametes are formed
gametes
sex cells (either sperm or egg)
diploid (2n)
two copies of the genome
haploid (n)
one copy of the genome
fertilization
combining of sperm and egg to form a zygote
zygote
diploid fertilized egg
chromosome
a single structure housing a single strand of DNA and associated proteins
chromatid
one of the two identical halves of a replicated chromosome
homologous chromosomes
a pair of chromosomes, one from mom and one from dad, with similar contents of DNA and are the same size
crossing over
exchange of DNA between homologous chromosomes
PMAT 1 (Meiosis 1)
first division in meiosis
PMAT 2 (Meiosis 2)
second division in meiosis
sexual reproduction
reproduction by meet of a sperm and an egg
daughter cell
cloned cell as a result of cell division
punnett square
a table used to find the possible results of crossing two genotypes together and the probabilities of obtaining those results
dominant
allele that is expressed in a genotype
recessive
allele that is not expressed in a genotype
allele
alternate form of a gene
trait
feature or character of an organism
law of segregation
equal probability for offspring to receive either allele from a parent
law of independent assortment
traits from genes are independent and do not influence eachother
heterozygous
different alleles
homozygous
same alleles
genotype
genes that you have
phenotype
physical appearance due to genotype
genetic linkage
genes on the same chromosome and are relatively nearby each other
sex-linked trait
trait due to a gene on a sex chromosome
incomplete dominance
both alleles blend if heterozygous
complete dominance
recessive allele not shown if heterozygous
codominance
both alleles are present on the phenotype seperately
nondisjunction
failure of chromosomes to seperate
How does meiosis result in the transmission of chromosomes from one generation to the next?
Meiosis produces gametes, which have chromosomes, and the gametes can fertilize with another individual’s gametes and their chromosomes and passion their chromosomes to the next generation offspring
What are the similarities and differences between the phases and outcomes of mitosis and meiosis?
Similarities: both produce new cells
Differences: Mitosis produces diploid clone daughter cells and has only one division. It produces somatic cells. Meiosis has two divisions that produce haploid gametes.
How does the process of meiosis generate genetic diversity?
Via crossing over, random fertilization, and independent assortment, meiosis and resulting fertilization produces offspring that are always genetically dissimilar from the parents, increasing genetic diversity
How do shared, conserved, fundamental processes and features support the concept of common ancestry for all organisms?
All organisms share certain processes and features like DNA, metabolic processes, etc, so the common ancestor of all life must have had these processes and features
How do Mendel’s laws describe the inheritance of genes and traits?
the law of segregation states that offspring have an equal probability to receive either allele from our parents
The law of independent assortment states that traits from genes are independent and do not influence each other
What are the deviations from Mendel’s model of the inheritance of traits?
Examples include sex-linked traits, linked genes, incomplete dominance, codominance, epistasis (a gene affects the phenotypic expression of another), polygenic inheritance (many genes influence one phenotype), pleiotropy (one gene influences multiple phenotypes), and multiple alleles (many alleles for one gene)
How can the same genotype result in multiple phenotypes under different environmental conditions?
An example is human height. Two individuals can have the same height initially, but different heights later depending on nutrition
