This document discusses genetic inheritance and heredity. It covers how traits are transmitted from parents to offspring through both sexual and asexual reproduction. Key concepts covered include meiosis, mitosis, chromosomes, genes, mutations, and the human genome. The role of environment and experiences in influencing traits is also noted. The document concludes by outlining some applications of genetics in biotechnology fields like bioinformatics, computational biology, and systems biology.

1. Genetic Inheritance
Module 4, BI 140

2. Contents
• Heredity and cell division
• Basic genetics
• Genetics in biotechnology

3. Heredity
• Heredity is the
transmission of
traits from
parents to
offspring
http://messybeast.com/mosaicism.htm

4. Heredity
• In sexual reproduction, half (or roughly half at
least) of genes comes from a father and the
other half come from a mother
– Human, animals, plants
• Asexual reproduction, all of the genes come
from a single parent
– Bacteria, fungi, plants

5. Heredity
• Some traits are directly from one parent (eg
sex) and some traits are a mixture from both
parents (eg skin color).
• Using Mendelian genetics, traits of offspring
can be predicted using statistics.

6. Cell division - Mitosis
• Mitosis - the cell creates an exact copy of
itself.
– Results in cells with the same number of
chromosomes as the parent cell
http://techhydra.com/wp-content/uploads/cell-division-full.jpg

7. Cell division - Meiosis
• Meiosis - the cell divides to create gametes
(egg or sperm) used for sexual reproduction
– Results in cells with half the number of
chromosomes as the parent cell
– Cross-over is the transfer of genes from one
chromosome to another. Cross-over only occurs
during meiosis

8. Chromosomes
Chromosomes are
condensed DNA
(genes)
Chromosomes are
visible under a
microscope during cell
division

9. Basic Genetics
• Genes code for proteins and proteins
influence traits
• All living things contain genes. Viruses also
contain genes.
– Humans have ~20,000 genes
– Ebola has ~7 genes
• Genes have variants (small changes) which can
cause major or minor changes to the protein it
codes for

10. Gene Expression
• Genes need to be expressed to create a
protein
– Just because you have a gene does not necessarily
mean that gene is going to be expressed
– Many “genes” in the human genome are never
expressed
http://www.extremetech.com/ext
reme/134672-harvard-cracks-
dna-storage-crams-700-
terabytes-of-data-into-a-single-
gram

11. Traits
• Traits (characteristics of an organism) are a
result of many factors including protein and
nucleic acid activities
• The more “complex” the trait, the more
complicated the genetics
• Consider twins. Twins have the same genome
and very similar traits; yet they are still
unique. This is because traits are a result of
environment and experiences during life.

12. Environment
• Phenotypic plasticity – the degree to which a
certain trait is affected by environmental
factors
• Environmental factors influence gene
expression and vice versa
– Food, water, air
– Parents, peers, other people
– Memories from all senses: visual, auditory,
physical, etc.
– Physical activities, choices, etc

13. Mutations
• A change in the single or a few amino acids in
a protein is called a mutation (also can be
called a variant)
• A mutation or variant may or may not alter
the structure or function of the protein
• A “bad” mutation can result in a disease
(Sickle Cell Anemia or certain cancers)
• A “good” mutation can result in beneficial
traits

14. Human Genome
• For humans, there are billions of base-pairs (A,
C, T, Gs) in the human genome and (maybe)
~26,000 genes that are actually expressed.
• Each of these genes can have a number of
variants and different expression patterns.
• The combination of genetics and experiences
is what makes each person unique.

15. Genetics in Biotechnology
• Three growing fields in biotechnology
– Bioinformatics
– Computational Biology
– Systems Biology
• These fields conduct research in support of:
– Clinical/medical research
– Biopharmaceutical discoveries and development
– Evolutionary biology
– Forensic biology
– Engineering

16. Bioinformatics
• The use of information technology
(computers, servers, etc) to study biology.
– Genetic and protein databases
– Software development for analysis and
comparison of gene and protein sequences
• Finding variants/mutations in genes and proteins
• Evolutionary biology

17. Computational Biology
• Using computers to model, visualize, predict,
simulate biological processes.
– Predict protein sequences
– Visualization of protein folding
– Predict protein interactions with chemicals
http://www.mdpi.com/1422-0067/14/8/16882

18. Systems Biology
• Determining the
molecular function
of a protein could
predict what could
happen if the
protein changes
http://abeautifulwww.com/GeneVisualizatio
ns_E01C/cerebralmapk.jpg
• The study of biological systems - Systems
biology attempts to define (the very complex)
biological processes