Meiosis and Inheritance

• Students should be able to apply knowledge and principles to solve new problems.

Meiosis

• Meiosis' purpose is cell division for sexual reproduction, producing gametes with half the number of chromosomes as the parent cell.
• Cells undergoing meiosis are germ cells (cells that produce gametes).
• Gametes need to be haploid to avoid doubling the chromosome number with each fertilization.
• Crossing over occurs during prophase I of meiosis, increasing genetic variation.
• Meiosis involves two cell divisions, resulting in four haploid cells, while mitosis involves one cell division, resulting in two diploid cells.

Inheritance

Mendelian Inheritance

• Dominant traits mask recessive traits in heterozygotes.
• Punnett squares predict the outcome of crosses and determine unknown genotypes based on offspring.

Non-Mendelian Inheritance

• Codominance results in both alleles being expressed in the phenotype.
• Incomplete dominance results in a blended phenotype.
• Punnett squares and inheritance knowledge can predict the outcome of crosses and determine unknown genotypes.

Genetic Variation

• Independent assortment increases allele variation.
• Crossing over increases allele variation.
• Each individual is genetically unique due to combinations of alleles.

Sex-Linked Traits

• Sex-linked traits are located on sex chromosomes.
• Inheritance of sex-linked traits differs from autosomal inheritance because of the unequal size of the sex chromosomes.
• Males are more likely to express recessive sex-linked traits due to having only one X chromosome.
• Punnett squares and inheritance knowledge can predict the outcome of crosses and determine unknown genotypes.

Polyallelic Traits

• Polyallelic traits have more than two alleles for a given gene (e.g., blood types).
• Polyallelic traits establish a dominance hierarchy among the alleles.

Gel Electrophoresis

• DNA fingerprinting uses gel electrophoresis, separating DNA fragments by size.
• Gel electrophoresis can analyze DNA to determine relationships or match samples.
• Restriction enzymes cut DNA at specific sequences.
• Gel electrophoresis separates DNA fragments based on size and charge.
• Gel electrophoresis is analyzed to determine relatedness or matches.

Geniventure

• Predict genotypes from phenotypes.
• Purple flowers indicate a dominant allele presence, but the exact genotype depends on dominance patterns.
• Identify the phenotype of two-trait genotypes.
• Infer parental genotypes from offspring phenotypes, predict gametes, analyze multiple traits, and recognize inheritance patterns.
• Identify incomplete dominance and predict genotypes.
• Cross heterozygotes and predict offspring ratios.
• Given data from a test cross, predict the parental genotype.
• Identify the correct genotype for a test cross.
• Genes provide information for traits.
• Albinism results from a lack of melanin production due to a gene.
• Proteins have diverse roles in organisms.
• The shape of a protein affects its function.
• Different versions of genes influence melanin production.
• Understand polyallelic crosses.
• Predict offspring sex-linked traits based on parental chromosomes.

Trait Tracker

• Identify and understand dragon traits, including dominant and recessive alleles.

Pedigrees

• Pedigree symbols and modes of inheritance should be understood.
• Phenotypes and genotypes of individuals in pedigrees should be identified.

DNA Review

• DNA structure involves nucleotides with a sugar, phosphate group, and nitrogenous base.
• Chromatin is loosely packed DNA, while chromosomes are tightly condensed DNA.
• Adenine pairs with thymine (A-T) and guanine pairs with cytosine (G-C).
• DNA strands are held together by hydrogen bonds between bases.
• 5' and 3' refer to the directionality of the DNA strand (the carbon atoms on the deoxyribose sugar).

Protein Synthesis

• RNA differs from DNA (single-stranded, ribose sugar, uracil instead of thymine).
• mRNA carries genetic code, tRNA brings amino acids, and rRNA is a component of ribosomes, the protein synthesis site.
• Transcription, occurring in the nucleus, involves RNA polymerase creating mRNA from a DNA template.
• Translation, happening in the cytoplasm, uses ribosomes to synthesize a protein from mRNA, with tRNA bringing the amino acids.
• Codons are three-nucleotide sequences coding for amino acids.
• Anticodons are tRNA sequences complementary to mRNA codons.
• tRNA transfers amino acids to the ribosome during translation.
• mRNA carries the genetic code from DNA to the ribosome.
• Codon charts translate mRNA codons into amino acids.

Mutations

• Mutations can occur during DNA replication or due to environmental factors.
• Mutations include substitutions, insertions, or deletions.
• Original and mutated DNA can be compared to determine the mutation type.
• Changes in amino acid sequence due to mutations can be determined.

Scientific Method

• Understand the steps of the scientific method.
• Recognize predictions and hypotheses.

Experimental Design

• Independent variable is manipulated, dependent variable is measured.
• Control group is the baseline, experimental group receives the treatment.
• Constants are factors kept the same.
• Quantitative data is numerical and Qualitative data is descriptive.

Graphing & Data Analysis

• Bar graphs, line graphs, and pie charts are used in different situations.
• Reading and interpreting graphs is essential.

Cells

• Prokaryotic cells lack a nucleus; eukaryotic cells have a nucleus.
• Cell parts include the nucleus, cytoplasm, organelles, and cell membrane.
• Each cell part has a specific structure and function.
• Plant cells have cell walls and chloroplasts.