Random Bio 142 Things

Monohybrid (Rr x Rr) cross with complete dominance

3:1 dominant to recessive

Monohybrid cross with incomplete dominance

1:2:1 (eg. red:pink:white flower)

Monohybrid cross with codominance

1:2:1 ratio for both alleles expressed (eg. 2 red and white flowers)

Dihybrid Cross (RrYy x RrYy)

9:3:3:1 ratio of phenotypes

Recessive epistasis

9:3:4 ratio in phenotypes.

Dominant epistasis

12:3:1 ratio in phenotypes.

siRNA

Perfect match, degrade mRNA, no protein be made because mRNA chopped up by an enzyme

miRNA

Imperfect match, block translation, blocks ribosome binding

Heterochromatin

A tightly packed form of DNA, which is associated with gene silencing and regulation, making genes less accessible for transcription.

Euchromatin

Less condensed form of chromatin that is actively transcribed, resulting in gene expression.

Methylation

Brings nucleosomes closer together and more compacted, blocks txn factor access to reg seq, changes major grooves’ atom, creates heterochromatin

Acetylation

DNA wrapped around the histone more loosely and allows txn factor access, creates euchromatin

Oncogene

Mutant form of proto-oncogene that causes too much cell division or inappropriate survival (connects with two hallmarks of cancer: self-sufficiency in growth signals/evading apoptosis)

Tumor Suppressor

Genes whose normal function is to inhibit cell division, induce cell death when necessary, or repair DNA damage (connected with hallmark of cancer: evading apoptosis)

Complementary recessive epistasis (duplicate recessive epistasis)

Recessive alleles at two different loci mask the expression of dominant alleles at both loci, resulting in a 9:7 phenotypic ratio in the F2 generation

Regulatory elements

Promoter, terminator, enhancer, silencer are DNA SEQUENCES

Transcription factors

General transcription factors, activators, and repressors are PROTEINS