GENETICS

Question 1

CHROMOSOMES

Answer 1

• tightly packed DNA
• 23 pairs of chromosomes with a nueclus of each cell
• Each chromosome is inherited from one parent
• Cells with 23 individual chromosomes are termed diploid (the presence of two complete sets of chromosomes in an organism’s cells, with each parent contributing a chromosome to each pair)
• gamets contain 23 individual chromosomes termed haploid (a cell that contains a single set of chromosomes)
• 22 of chromosomes pair are identical 23 (sex chrmomosome) is different

-m cells without chromosomes are red blood cells and sex cells (sperm and egg)
- containg genetic code for individual,
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Question 2

DEOXYRIBONUCLEAIC ACID (DNA)

Answer 2

• carries genetic code for organisms
• information encoded by 4 different bases based on nucleotide
• maintains the structure of the bases are paired with complementary bases: adenine to thymine and cytosine
• Genes are part of DNA that encode for specific proteins
• DNA exists with mitochondria

Question 3

PROTEIN SYNTHESIS

Answer 3

TRANSCRIPTION: DNA converted to messenger RNA moves out into the cytoplasm

TRANSLATION: ribosomes use transfer to DNA = peptide changes

Question 4

PROTEIN SYNTEHISIS-TRANSCRIPTION

Answer 4

• strands unwind and separate
• nucleotides made from ribose sugars in the enzyme unwinding the DNA to match the bases on the DNA strand
• The process continues until the code stops on the DNA strand
• Strands of ribose sugar nucleotides turned into messenger RNA
• NA is a nucleic acid that has a ribose sugar instead of a deoxyribose sugar, is more content as a single stranded molecule and replaces the thymine base with uracil, this is because RNA nucleotides cannot be made with thymine.

Question 5

PROTEIN SYNTHESIS - TRANSLATION

Answer 5

• mRNA leaves the nucleus & quickly attaches to the ribosome
• happens outside of endoplasmic reticulum
• ribosomes read the mRNA codes & get amino acids
• code reads in 3, total those gives 64 different possible combinations

Question 5

PROTEIN SYNTHESIS - MUTATIONS

Answer 5

• process of the code of DNA being changed by numerous factors
• different types: point mutation (swapping of a single base), insertion, subtraction (removal of one/more bases from DNA code), substitution (changes of complete codon 3 bases (CF point mutation which is substitution of a single base) , inversion (switching oreintation of codon or longer areas of bases
• fundamentally change the structures of protein, making useless/dangerous

Question 6

INHERITANCE

Answer 6

• Each chromosome contains genetic coding for a trait
• Alleles are different versions of the same gene
• Genotype is a collection of alleles that determine characteristics
• phenotype characteristic that is expressed
• 2 of the same alleles (homozygous)
• 2 different alleles (heterozygous)
• Autosomal dominate alleles are always shown in phenotype
• Autosomal recessive alleles are only shown in phenotype in homozygous recessive
• Punnett squares are used to calcualte the probailbity of an offspring having a particar genotype or phenotype

Question 7

PUNNETT SQUARES

Answer 7

• place maternal genotype on one axis and paternal on the other
• each gene combined with the other parent gene to estimate the genotype
• punnett square of multiple genes can be combined to assess the probs of multiple genetic combos

Question 8

CO-DOMINANCE

Answer 8

• 2 alleles are equally dominant and will both be expressed in the phenotype
• multiple phenotypes and not just the normal 3
• blood group show 4 phenotype the 4 blood groups A,B,AB AND O
• probability can be examined using punnett squares