ch 11 exam 4 Flashcards
(25 cards)
Who was the father of heredity?
Gergor Mendel
What did Mendel study?
pea plants
What is the law of independent assortment?
Each factors are passed to the next generation independently from
all other factors (eye color is brown, hair is red they don’t coorispond)
What is the law of segregation?
2 alles coding for the same triat sepate during meiosis (one from mom and dad you only keep one)
What are alternative factors(gene) called?
alleles
What is a true breeding organism?
have two alleles that are
identical (HH or hh)
What is a hybrid organism?
When two true breeding plants mate that are different in their
genes, they produce hybrids (Tt) – heterozygotes
What do the terms homozygous dominant, homozygous recessive and heterozygous mean?
homozygous dominant- HH
homozygous recessive- hh
heterozygous- Hh
What is a gene loci (locus?)
the site a gene occupies in the chromosome
How are dominant and recessive alleles different?
dominant covers ressive
How are phenotype and genotype different?
genotype is the genetic makeup
phenotype is the physical characteristic
What is the purpose of a Punnett square?
a grid arrangement that shows the possible combinations of alleles
What are haploid and diploid cell?
haploid have half and are sex cells
diploid are complete and are body cells
What is the purpose of a test cross?
cross an individual of unknown genotype with a recessive individual to determine the unknown genotype (see if its FF or Ff)
What is a dihybrid cross?
punnett square that crosses 2 traits (FFff with FFF) 16 squares
How do you know the possible gametes for a dihybrid cross?
do the punnett square and get the ratios
What is transformation and which scientist discovered it?
Fredrick Griffith- DNA can transform a nonviral bacteria into a viral one. (mouse experiment)
Which scientists studied bacteriophages to prove DNA is the genetic material?
Alfred Hershey and Martha Chase
List the genetic disorders we discussed in class. Be able to describe them. (5)
- Trisomy 21 – Down Syndrome
-Trisomy 18 – Edwards Syndrome
-Trisomy 13 – Patau’s Syndrome
-Cri-du-Chat Syndrome - missing genes on chromosome 5
-Prader Willi Syndrome – defect on Chromosome 15, uncontrollable hunger
What is a sex linked trait? What gender is mostly effected if it is recessive?
characteristics (or traits) that are influenced by genes carried on the sex chromosomes
Males are more likely to be affected in recessive X linked disorders
What does the term epistasis mean?
An allele of one locus can mask the expression of alleles of a different locus and express their own phenotype instead (fur color in labs)
What does the term pleiotropy mean?
the ability of one gene to have several effects on different characters (protein build up in the brain messes up more than just the brain)
What is codominance?
the heterozygote simultaneously expresses phenotypes of both homozygotes (blood type- AB)
What is incomplete dominance?
the heterozygote is intermediate in
phenotype (red + white= pink)
