Genetics

Heterozygous

Having two different alleles for a gene

Homozygous

Two identical alleles of the same gene

Phenotype

Physical appearance

Genotype

An organism’s genetic makeup that determines its potential traits

Benefits of variation

Helps species adapt to changing environments

How mutations can provide variation

By creating new alleles

What is the name of an environmental factor that caused a mutation?

Mutagen

When can a mutation be passed on?

When it occurs in the gametes

Are mutations always bad?

No, can be beneficial, harmful, or silent

Mutagen

Factor that causes mutations

Crossing over

The splitting up of genetic material between homologous pairs

Segregation

The splitting up of homologous pairs into separate gametes

Independent assortment

The random order chromosomes line up during meiosis

Sources of variation from meiosis

Independent assortment

Segregation

Crossing over

Why is meiosis carried out?

To produce gametes and create genetic variation

Mitosis

Needs to be the same so it has all the original genetic material

How much genetic material from Meiosis

Has ½ the genetic material because the other half will come from the other gamete

How many chromosomes in each daughter cell produced by

Mitosis = 46

Meiosis = 23

What cells replicate by meiosis

Testies and ovaries cells

How many cells are made by meiosis?

4 daughter cells, 23 chromosomes

What cells replicate by mitosis

Everything except the sex or body cells

What is the purpose of mitosis?

growth, repair, asexual reproduction

How many cells are made from mitosis?

2 cells, 46 chromosomes

Why do cells die?

Growth and repair

Humans have 23 pairs of chromosomes. Where do we get each chromosome in the pair from?


One chromosome inherited from the mother and one chromosome inherited from the father.

Blue eyes

ATCGTA

Brown eyes

ATGGTA

How is variation helpful

It allows populations to adapt to changing environments, withstand diseases, and persist over time.

How does DNA replicate?

Unzips, uses each strand as a template using the base pairing rule. “Semi conservative”

What does a gene code for?

A protein or trait

Asexual reproduction con

there is no genetic variation

Asexual reproduction pro

you only need 1 person, its faster, the gametes don't need to find each other

Sexual reproduction con

It is slower, it can be difficult to find a partner, and takes time to grow from a zygote to a fetus.  

Sexual reproduction pro

There is variation

Sexual reproduction

The process where two parents produce offspring by combining their gametes

Asexual reproduction


The process where a single parent produces offspring without gametes, resulting in genetically identical clones.

Variation

The differences in traits among individuals within a population or species

Mutation

The permanent change in the base sequence of DNA

Chromosome

A section of DNA that codes for multiple genes

Allele

An alternative form of a gene

DNA

Molecule that contains genetic information

Structure of DNA


(Deoxyribose nucleic acid) a double helix

Gene

A short length of DNA that codes for a trait

Dominant

AA

Recessive

aa

Zygote

the first cell of a new organism, formed when a sperm cell fertilizes an egg cell

Gamete

a reproductive cell

Natural selection

Survival of the fittest

Pure breeding

Breeding homozygous individuals

Why do we track genes?

To track mutations and diseases 

What can tracking genes tell us? 

If it is inherited or not 

What is a test cross, and why is it done?   

When you are checking if a species is homozygous dominant or heterozygous for a trait by crossing with homozygous recessive. We cross it with a recessive because we know its genotype.   

What is natural selection

Survival of the fittest, where beneficial alleles become more frequent, and harmful alleles less frequent.  

How do “bad” genes get eliminated from the population?

Individuals die before reproduction