BIO110- Chapter 5

BIO110- Chapter 5

Chapter Outline

Cell division types and functions

Chromosomes

The Cell Cycle and Mitosis

Gametes

Meiosis

Genetic variation in Sexual reproduction

Mistakes in Meiosis

Mendelian Genetics

Punnett Squares

Mendel's Laws

Pedigrees

Inheritance Patterns

Sex-Linked genes

Clones

Cell division Types and Functions

• Sexual vs asexual (compare & contrast)

• Advantages of each type

Multiple Choice

The type of reproduction that creates identical offspring

• sexual

• asexual

Multiple Choice

The type of reproduction that requires two parents and the use of gametes

• sexual

• asexual

Multiple Choice

Which type of reproduction has the advantage of creating genetic variation?

• sexual

• asexual

Chromosomes

• How many chromosomes are in human cells?

• Describe the structure of chromosomes

Multiple Choice

The top two arrows in the picture are pointing to:

• centromeres

• sister chromatids

• genes

Multiple Choice

The sister chromatids are being held together by:

• telomere

• centromere

• genes

The Cell Cycle and Mitosis

• Interphase- what's going on?

• The Mitotic phases (PMAT)

• Cytokinesis (how is it different in plants and animals?)

Multiple Select

Select the following functions that occur during Interphase of the cell cycle

• Normal cell activities

• Cell division

• Preparing for cell division

• Growth

Multiple Choice

Which phase of mitosis is this?

• Prophase

• Metaphase

• Anaphase

• Telophase

Multiple Choice

Which phase of mitosis is this?

• Prophase

• Metaphase

• Anaphase

• Telophase

Multiple Choice

In an animal cell, cytokinesis will form a:

• cell plate

• cleavage furrow

Multiple Choice

What is the end result of a round of mitosis?

• 2 non-identical daughter cells

• 2 identical daughter cells

• 4 non-identical daughter cells

• 4 identical daughter cells

Gametes

• What is the difference between diploid and haploid?

• Define a karyotype – what does it show you?

• What are homologous chromosomes?

Multiple Choice

A gamete is:

• haploid

• diploid

Fill in the Blanks

Multiple Choice

True or false: Homologous chromosomes contain the same genes.

• True

• False

Fill in the Blanks

Meiosis

• Meiosis produces gametes (by halving the ploidy)

• Describe what is happening in Meiosis I and Meiosis II (in each part of PMAT)

Multiple Choice

"Separating the homologous pairs" happens during:

• Meiosis I

• Meiosis II

Multiple Choice

"Separating the sister chromatids" happens during:

• Meiosis I

• Meiosis II

Multiple Choice

Which part of meiosis is identical to mitosis, except it is happening twice?

• Meiosis I

• Meiosis II

Multiple Choice

What is this picture showing?

• Meiosis I

• Meiosis II

Genetic variation in Sexual reproduction

• Crossing over (Prophase I)

• Independent assortment (Metaphase I)

• Random fertilization

Multiple Choice

When does crossing over occur?

• Prophase I

• Prophase II

• Metaphase I

• Metaphase II

Multiple Choice

When does independent assortment occur?

• Prophase I

• Prophase II

• Metaphase I

• Metaphase II

Mistakes in Meiosis

• Define nondisjunction

• What happens to a cell/individual/offspring that has an abnormal number of chromosomes?

Multiple Select

Nondisjunction can occur in:

• Meiosis I

• Meiosis II

Open Ended

Give an example of a condition caused by nondisjunction

Mendelian Genetics

• Heredity/Genetics

• Character/Trait

• Allele

• Genotype

• Phenotype

• Dominant/Recessive

• Homozygous/Heterozygous

Punnett Squares

• Monohybrid cross – genetic cross following a single character

• Dihybrid cross – genetic cross following two characters

• Test cross – genetic cross between an individual of known genotype to determine unknown genotype of another individual

Mendel's Laws

• Law of segregation of alleles – a pair of alleles for any given character separates; one allele will go into half of the gametes and the other allele into the other half of gametes

• Law of independent assortment – the inheritance of one character has no effect on the inheritance of another

• The exception to Law of independent assortment is linked genes (genes located closely together on a chromosome they are inherited together). Also often not subjected to genetic recombination via crossing over

Pedigrees

• Can be used to trace traits in human families

• Be sure to understand the basics of reading a pedigree

• Human genetic characters are often described as wild-type (most often seen in a population) or mutant (less often seen)

• Carriers are heterozygous individuals (one dominant allele and one recessive allele) who physically do not show the trait but can pass on the recessive trait to their offspring (Most often seen in genetic disorders that are recessive)

Inheritance Patterns

• Incomplete dominance

• Multiple alleles

• Codominance

• Pleiotropy

• Polygenic inheritance

• Environment vs genetics (epigenetics)

Sex-Linked Genes

• Autosomes – 44 of the 46 chromosomes common to all humans

• Sex chromosomes – 2 of the 46 chromosomes that differ between males and females. In females, with two X chromosomes, sex-linked recessive traits are less commonly seen. In males, with only one X chromosome, sex-linked genes are more common. The Y chromosome is not homologous and therefore cannot mask any traits on the X chromosome. Examples: color blindness, hemophilia

Clones

• What are the different types of cloning? How do they differ in technique?

• Nuclear transplantation

• Plant cloning

• Reproductive cloning

Genetics Practice

IN a moment, I am going to close this lesson and put you into breakout rooms to complete your class assignment "Genetics Practice" with your classmates.