Genetics Flashcards
Describe the structure of DNA and its location within cells.
DNA is a double helix made of nucleotides (A, T, C, G).
Located in the nucleus of cells, organized into chromosomes.
Know that Chromosomes contain many genes
Chromosomes contain many genes, which are sections of DNA that code for traits.
Understand that there are multiple patterns of inheritance (Look into further on powerpoint)
Inheritance can be dominant/recessive, co-dominant, or sex-linked.
Meiosis
Definition: Cell division producing four genetically diverse haploid cells.
Purpose: Produces gametes (sperm and eggs) for sexual reproduction.
Process:
Meiosis I: Homologous chromosomes separate (crossing over increases diversity).
Meiosis II: Sister chromatids separate.
Outcome: Four non-identical haploid cells (23 chromosomes in humans).
Mitosis
Mitosis
Definition: Cell division producing two genetically identical diploid cells.
Purpose: Used for growth, repair, and asexual reproduction.
Process: One division where chromosomes line up, separate, and reform nuclei.
Outcome: Two identical diploid cells (46 chromosomes in humans).
Key difference of meiosis and mitosis
Meiosis: Four cells, haploid, genetic diversity.
Mitosis: Two cells, diploid, identical.
Know that DNA is the blueprint for controlling the characteristics of organisms.
DNA controls organism traits by encoding proteins that affect characteristics.
Recognise that genetic information passed on to offspring is from both parents by meiosis and fertilization
Genetic information is passed from both parents via meiosis (producing haploid gametes) and fertilisation.
Know the role of genetic testing in decision-making relating to embryo selection and identification of carriers of genetic mutations
Used to identify carriers of mutations and aid in embryo selection or detecting genetic disorders.
Understand Dominant/Recessive inheritance occurs on an autosome
In autosomal inheritance, a dominant allele masks a recessive one.
Describe Alleles as variants/different forms of a gene.
Alleles are different forms of the same gene (e.g., dominant or recessive).
Understand how/why Chromosomes occur as homologous pairs in body cells.
Chromosomes occur in homologous pairs in body cells, one from each parent.
Show how Genetic information is passed on to offspring from both parents via haploid cells.
Haploid cells (sperm/egg) carry one set of chromosomes and combine during fertilization to form a diploid organism.
Haploid Cell
Haploid describes a cell that contains a single set of chromosomes. The term haploid can also refer to the number of chromosomes in egg or sperm cells, which are also called gametes. In humans, gametes are haploid cells that contain 23 chromosomes, each of which a one of a chromosome pair that exists in diplod cells.
Diploid Cell
A cell containing two copies of each chromosome is referred to as a ‘diploid cell’; human somatic cells are diploid: they contain 46 chromosomes, 22 pairs of autosomes and a pair of sex chromosomes.
Predict simple ratios of offspring genotypes and phenotypes in crosses involving dominant/recessive gene pairs.
Punnett Squares
Correctly use the biological terms associated with the study of genetics: Gene, chromosome, DNA, nucleotide, homologous pair, diploid, haploid, dominant, recessive, homozygous, heterozygous, genotype, phenotype.
Gene: Unit of heredity.
Chromosome: Structure carrying DNA.
DNA: Molecule containing genetic code.
Nucleotide: Building block of DNA.
Haploid/Diploid: Single vs. double chromosome sets.
Dominant/Recessive: Allele types.
Homozygous/Heterozygous: Same vs. different alleles.
Genotype: Genetic makeup.
Phenotype: Physical traits.
Analyse karyotypes to identify gender and genetic abnormalities
Examine karyotypes to identify gender (XX or XY) and genetic abnormalities (e.g., Down syndrome).
Drawing a nucleotide
Draw the Sugar: Sketch a pentagon for deoxyribose (DNA) or ribose (RNA).
Add the Phosphate Group: Draw a circle labeled “P” attached to one corner of the pentagon.
Draw the Nitrogenous Base: Next to the sugar, draw a base:
Adenine (A): Two rings.
Thymine (T) or Uracil (U): One ring.
Cytosine (C): One ring.
Guanine (G): Two rings.
Connect Components: Draw lines to connect the phosphate to the sugar and the sugar to the base.
Label: Clearly label each part (sugar, phosphate, base).
