1. Benchmark 3 Review
Notes
Honors Biology

2. Asexual Reproduction
Only one parent required
Genetically identical offspring created
Uses MITOSIS to make clone organisms
No gametes used

3. Types of Asexual
Reproduction
• Budding  Used by yeast and hydra
• Vegetative  Used by plants
• Binary Fission  Used by bacteria
QUESTION:
Which type of asexual reproduction
is shown to the right???

4. Sexual Reproduction
• Gametes are produced by the process of meiosis
– Crossing-Over of Meiosis I ensures genetic variation
between offspring
– Gametes are HAPLOID cells (N)
• Egg and sperm unit to form a zygote
– Zygote is the first DIPLOID cell (2N) of a new
individual. The zygote becomes a fully-formed
individual through mitosis

5. Production of Gametes

6. If a somatic cell has 100
chromosomes. . .
• Cells undergoing • Cells undergoing
MITOSIS will have MEIOSIS will have 50
100 chromosomes chromosomes each
each
• HAPLOID cells
• DIPLOID cells created created

9. Genetics Review
Genotypes Phenotypes
• Two alleles for an • Physical
autosomal trait characteristics
• HH – homozygous
dominant • Hh and HH create the
• Hh – heterozygous same phenotype
• Hh – homozygous
recessive

10. Punnett Squares for Autosomal
Traits
• What percentage of
children will have the
dominant
phenotype?
• What percentage of
children will have the
recessive
phenotype?

11. Sex-Linked Traits
• Carried on X- • Boys receive X-
chromosome chromosome and its
alleles from MOM
• Recessive alleles
cause disorders like • Use a SPECIAL
colorblindness, Punnett Square to
hemophilia, and predict
baldness

12. Sex-Linked Punnett Squares
• What percent of
males inherit the
disorder?
• What percent of
females are carriers
for the disorder?

13. Pedigrees
• Study the
pedigree to
the right.
• What kind of
trait is shown?
Explain. . .

14. DNA and RNA
• DNA is double- • RNA is single-
stranded stranded
• Base pair rules: • Makes a single-strand
– A—T copy off an open DNA
– C—G strand
• For ATT-CGA: what is • For ATT-CGA: what is
the complementary the complementary
DNA strand? RNA strand?

16. Functions
• DNA: contains thousands • RNA:
of genes written as
nucleotide sequences mRNA: carries gene information
from nucleus to ribosome
• Genetic code determined rRNA (ribosome): site where
mRNA instructions are read
by DNA nitrogen base
tRNA: carries amino acid to
sequence ribosomes according to mRNA
instructions
• Kept in the nucleus of
eukaryotic cells

17. Steps of Protein Synthesis
TRANSCRIPTION:
• DNA gene opens to attach mRNA nucleotides
• mRNA copies DNA gene in the nucleus
• DNA closes back up as mRNA exits
TRANSLATION:
• mRNA attaches to a ribosome where tRNA
brings correct amino acids

19. Two Important Types of
Gene Technology
Gene splicing Genetic Engineering
• Genes from an organism • Used to replace undesired
are removed and inserted genes of an organism with
into another organism better ones
Example: inserting human Example: Glow in the dark
insulin-producing gene in puppies are created by
bacteria to produce insulin inserting the glowing gene
quickly and economically from jellyfish into the dog
DNA

21. Gel Electrophoresis
• Used to determine relatedness of
organisms
• Separates DNA bands by size
• Shorter segments travel the furthest
through the matrix

22. More Matching Bands = Closer
Relatedness