Biology Exam Revision

Genes

a section of DNA that carries the code to make a protein

Alleles

Variant for of a gene

Genome

Entire set of DNA found in a cell

Homologues Chromosomes

• Same Shape and Size

• Same genes located in the same location

• Inherited by mother (maternal)

• Inherited by Father (Paternal)

Autosomes

One of hundred chromosomes that is not a sex chromosome

Sex Chromosomes

Chromosomes that carry the genes to determine the sex of a Person

variability of chromosomes in terms of size and number in different organisms

Human: 23 Pairs (46), as they have more genetic information

Karyotypes

Provide a snapshot of complete set of chromosomes in the metaphase stage of miosis.

detects abnormalities for potential diseases etc

karyotypes as a visual representation that can be used to identify chromosome abnormalities

• Missing or Extra chromosomes

• Inversion in size

the significance of crossing over of chromatids and independent assortment for genetic diversity

• Crossing over and independent assortment

• create genetic diversity by reshuffling alleles during sexual reproduction.

Dominant (Heterozygus)

expressed even if only one copy is present

Recessive

the variant of a gene that is masked by a dominant allele on a homologous chromosome

Codominance

Both alleles are equally expressed in the phenotype of the heterozygote. Neither is dominant or recessive.

Incomplete dominance

expresses a phenotype that is an intermediate blend of the two alleles.

trisonomy

One extra Chromosome

Tetrasomy

Two Extra Chromosomes

Monosomy

One missing Chromosome

Polyploidy

Additional set to genome

epigenetic factors

environmental influences that modify gene expression without changing the DNA sequence itself

biological advantages of asexual reproduction

• Fast reproduction

• Energy efficient

• Stable Offspring

Biological disadvantages of Asexual reproduction

- Lack of Genetic diversity
- Difficulty in Adaptation

Biological advantages of sexual reproduction of genetic diversity of variation

- Increased genetic variation
- Better Adaptation
- Evolutionary Potential

The biological importance of genetic variation with a species population

- Enhanced survival
- Better Adaptation
- Prevents risk of inbreeding issues (Harmful mutations)

Survival through independicis between Keystone species

- Impact of removal (loss of habitat etc)
- Maintaining Ecosystem balance

Survival through interdependencies between predators

- Tropic cascades( Food Webb affected and more)
- Natural selection

Aboriginal contributions

Fire management, water management

SCNT (somatic cell nuclear transfer)

retrieve egg, remove nucleus, somatic cell remove nucleus, put into the cell, ZAP! with electricity so they divide into embryo

Embryo splitting cloning

Single embryo is divided into two individuals cellls which become 2 individual cells

r-selected species

High Mortality
High Reproduction

K selected

Low reproduction
Parental care
Low mortality

Commensalism

one organism benefits and the other is unaffected

Ammensalism

relationship when one organism is harmed, the other is unaffected

Mutalism

both species benefit

Nuetralism

When neither organism is affected

Bioethical issues

• Validity (Consent)

• If its Worth it

• Animal welfare/Human Benefit

• If they are sufficient to protect animals

• Respect

Dihybrid Cross

4×4 table

Punnett Square

2 × 2 Table for ratios and phenotypes

Monohybrid Cross

2 × 2 table for chance of gene

Genetic Diversity

Variation of genes for species to adapt within the environment changes and evolution

X Linked Dominant

In a pedigree, where every single female is affected by the father.

Y Linked

Fathers only passes it to sons

linked genes

genes that are found close together on the same chromosome and are likely to be inherited together

homozygous

having identical alleles for the same gene on homologous chromosomes