CST Review
Genetics I.
Standards:
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BI5. a. Students know the general structures and
functions of DNA, RNA, and protein.
BI1. d. Students know the central dogma of molecular
biology outlines the flow of information from transcription
of ribonucleic acid (RNA) in the nucleus to translation of
proteins on ribosomes in the cytoplasm.
BI2. a. Students know meiosis is an early step in sexual
reproduction in which the pairs of chromosomes
separate and segregate randomly during cell division to
produce gametes containing one chromosome of each
type.
BI2. b. Students know only certain cells in a multicellular
organism undergo meiosis.
Standard Summaries
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BI5. a. The structures and jobs of DNA, RNA, and
protein.
BI1. d. The central dogma-Genetic instructions are
transcribed (copied) into mRNA in the nucleus, then the
genetic instructions are translated into proteins on
ribosomes in the cytoplasm.
BI2. a. Meiosis produces sex cells, chromosomes pairs
are separated randomly during this process, producing
gametes containing one chromosome of each type
(haploid).
BI2. b. Only sex cells (gametes) are produced meiosis.
Objectives:
explain the genetic factors that influence
the way we look.
 recognize that DNA contains the genetic
information that determines the way we
look.
 explain the structure and function of DNA.
 understand the general pathways by which
ribosomes make proteins.
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Part I. DNA Basics and The Central
Dogma
DNA Basics
Double helix=twisted ladder
 Chromosomes=chains of DNA and
proteins.
 Contains your genetic info (instructions to
make proteins)
 Sequences of DNA=Genes
 Genes=codes for proteins=instructions for
traits
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What is the central dogma?
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The central dogma describes the flow of
information from DNA to RNA to proteins.
Central Dogma-Protein Synthesis
DNA is transcribed to mRNA in the
nucleus (transcription)
 mRNA carries the genetic information into
the cytoplasm
 Proteins are assembled at the ribosomes
based on the “code” carried by the mRNA
(translation)
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How does your DNA determine
what you look like? I.
Your traits are inherited from your parents.
This means DNA is passed on from
generation to generation in the form of
chromosomes. The codes of the DNA
called genes have the instructions for your
traits.
Part II. Cell Cycles and Inheritance
of Traits
The Cell Cycle-DNA is copied and
the cell divides (Mitosis)
DNA
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DNA contains the info to make cells, and
we are made of cells…then DNA
determines our cellular and molecular
make-up which determines what we look
like.
How does your DNA determine
what you look like?II.
Your traits are inherited from your parents.
This means DNA is passed on from
generation to generation in the form of
chromosomes. The codes of the DNA
called genes have the instructions for your
traits. You inherit one copy of each gene
from each parent giving you a certain
genetic make-up that determines your
physical make-up.
Where does our DNA come from?
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½ your chromosomes from your momma
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½ your chromsomes from big poppa
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You have 23 pairs of chromosomes (46
total)
How does the DNA get from our
parents to us?
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Sex cells are produced by our parents
(meiosis) and then fuse together during
fertilization to combine their genetic
information (chromosomes).
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That’s why we look like our parents, but
not exactly like our parents.
Fertilization