Do Now:
Assign Punnet Sq. Challenge - This
To be completed:
Complete the Punnett Sq. Challenge
homework as needed
This is the daily classroom agenda for Paxton Center School Grade 7 Science. Lesson plans, homework, and other relevant information will be posted here each class.
homework as needed
DI: Genotypes
All sexually reproducing organisms have 2 parents
Genotypes are written showing 2 alleles
(one inherited from each parent)
Ex. Bb, TT, tt
What symbols should be used?
Use the first letter of the dominant phenotype (form)
Use the same letter for both dominant and recessive phenotypes
Uppercase - dominant
Lowercase - recessive
Dominant alleles are always written first
Write only genotypes to match the phenotypes of the individual.
Write two allele symbols for each genotype.
Homozygous - both alleles are the same (either dominant or recessive)
Heterozygous - one allele is dominant and the other is recessive
Dominant phenotypes can be homozygous - RR or heterozygous Rr
Either way the dominant allele shows (expresses)
Recessive phenotypes are always homozygous - rr
Any dominant allele would mask the recessive
BE SURE YOU HAVE FINISHED THE “TRAIT INVENTORY ASSIGNMENT AND TURNED IT IN!
Vocabulary:
Fertilization - joining of egg an sperm
(in humans results in 23 pairs of chromosomes)
Zygote - fertilized egg
able to grow through mitosis
Meiosis - cell division process that makes sex cells
produces haploid cells with random 1/2 of the chromosomes
Each sex cell is unique - never duplicates
insures all offspring are unique
Diploid - body cells with pairs of chromosomes
Haploid - sex cells with random 1/2 of the chromosomes
Advantages of Sexual reproduction
Increased genetic diversity
makes diverse organisms
differences may be an advantage that increases survival
two parents contribute genetic material
Each gives 1/2 of the DNA
create genetically unique offspring
used by animals, plants, fungi, and protists
Egg - female sex cell (animals)
made in ovaries
(in humans contains 23 single chromosomes)
pollen in plants
Sperm - male sex cell (animals)
(in humans contains 23 single chromosomes)
made in testis
ovule in plants
fertilization - joining of egg an sperm
(in humans results in 23 pairs of chromosomes)
Zygote - fertilized egg
able to grow through mitosis
Meiosis - cell division process that makes sex cells
produces haploid cells with random 1/2 of the chromosomes
Diploid - body cells with pairs of chromosomes
Haploid - sex cells with random 1/2 of the chromosomes
Increased genetic diversity
makes diverse organisms
differences may be an advantage that increases survival
Quiz tomorrow?
Pages 235 to 237 (Sexual Reproduction) of Chapter 7 Reproduction of Organisms.
Complete the "Sexual Reproduction QnA Wksht
use the chapter reading for your source of information - not Google
Watch the "Read along" video for help
Complete the "Mapping Sexual Reproduction" google drawing.
Turn it all in!
Breakouts anyone?
Asexual reproduction
one parent produces one or more offspring
offspring genetically identical to parent
occurs via various methods
Forms of Asexual Reproduction
Advantages of Asexual Reproduction
fast reproduction
no need for mate - less time/energy
get to pass on all your genes - not half with a mate
Disadvantages
low/no genetic diversity
all offspring may be susceptible to a change in conditions
This will be due after vacation but you will avoid extra work the day we return!