Structures
This structure is the middle point that joins the two sides of the chromosome.
Centromere
___________________ refers to the allele combination an organism has for a specific gene. It is often represented by letters.
___________________ refers to the physical expression of a gene.
Genotype
Phenotype
What are the first two steps in DNA replication?
Untwisting & unzipping
Create a punnett square and predict the probability of the offspring's phenotypes.
B=black fur
b=yellow fur
CROSS TWO HOMOZYGOUS YELLOW LAB DOGS
100% chance of having yellow lab puppies.
Write the complementary DNA strand to the following nitrogen base sequence:
CTAGGTTACGGTA
GATCCAATGCCAT
This structure is shaped like a letter and contains all of the genetic information for an organism.
Chromosome
BB is a ___________________ genotype and
Bb is a ___________________ genotype.
Homozygous
Heterozygous
On a pedigree, what symbol would indicate an affected female?
Shaded circle
Create a punnett square and predict the probability of the offspring's phenotypes.
B=black fur
b=yellow fur
CROSS TWO HETEROZYGOUS BLACK LAB DOGS
Bb x Bb = BB, Bb, Bb, bb
75% chance of black lab puppies,
25% chance of yellow lab puppies.
Look at the image pulled up on the whiteboard,
Which cell is undergoing metaphase? How can you tell?
D - the chromosomes are lined up in the middle
A chromosome is comprised of two identical _____________.
Chromatids
A ___________________trait will always be physically expressed if present in a genotype.
A ___________________ trait will ONLY be expressed if paired with another ___________________ allele.
Dominant
Recessive, Recessive
What happens after the first two steps of DNA replication?
Create a punnett square and predict the probability of the offspring's phenotypes.
B=black fur
b=yellow fur
CROSS ONE HETEROZYGOUS BLACK LAB DOG with ONE HOMOZYGOUS YELLOW LAB DOG
Bb x bb = Bb, Bb, bb, bb
50% chance of black lab puppies, 50% chance of yellow lab puppies
Look at the image pulled up on the whiteboard,
Which cell is undergoing prophase? How can you tell?
B - the genetic material has started to condense and make shapes
Chromosomes are found in the ________________.
Cell nucleus.
Provide one example of each:
- Helpful trait
- Harmful trait
- Neutral trait
Ex)
Helpful - Camouflage
Harmful - Genetic diseases
Neutral - Eye color
On a pedigree, what symbol would represent an unaffected male?
Unshaded square
Create a punnett square and predict the probability of the offspring's phenotypes.
B=black fur
b=yellow fur
CROSS TWO HOMOZYGOUS BLACK LAB DOGS
BB x BB = BB, BB, BB, BB
100% chance of black lab puppies
Look at the image pulled up on the whiteboard,
Which cell is undergoing anaphase? How can you tell?
F - the chromosomes have been pulled apart
___________________ is tightly packed together to form a chromosome.
DNA/Chromatin
Describe what occurs for each of the following mutation types:
- Addition
- Deletion
- Substitution
Addition - new base pairs added
Deletion - base pairs removed
Substitution - base pairs get swapped out
Adenine, Guanine, Thymine, Cytosine:
which pairs with which?
(A+T) and (C+G)
Create a punnett square and predict the probability of the offspring's phenotypes.
B=black fur
b=yellow fur
CROSS ONE YELLOW LAB DOG WITH A HOMOZYGOUS BLACK LAB DOG.
BB x bb = Bb, Bb, Bb, Bb
100% chance of black lab puppies
Look at the image pulled up on the whiteboard,
Which cell is undergoing telophase? How can you tell?
G - two separate cells have started to form, you can see the two separate nucleus.