Genetics and Heredity Overview

DNA, or deoxyribonucleic acid, is the genetic material inherited from parents that controls all the chemical changes in cells, serving as a blueprint for traits in offspring.

Genes are segments of DNA that are passed from parents to offspring, determining specific traits and contributing to the similarities between generations.

Punnett Squares are used to predict the probability of inheritance patterns for specific traits in offspring based on the genetic makeup of the parents.

<p>Inherited traits evolve at the population level through genetic variation and natural selection, influencing which traits become more common or rare over generations.</p> Signup and view all the answers

<p>Analysing patterns of inheritance is crucial for understanding genetic diseases, predicting trait distributions, and improving breeding programs in agriculture and conservation.</p> Signup and view all the answers

<p>Mitosis results in two identical cells, each containing the same genetic information as the original cell.</p> Signup and view all the answers

<p>Meiosis produces four daughter cells, while mitosis produces two identical cells.</p> Signup and view all the answers

<p>Each gene pair in an offspring originates from one gene inherited from the male parent and one from the female parent.</p> Signup and view all the answers

<p>Mendel was the first biologist to use mathematics to explain genetic inheritance and introduced the concepts of genes and gene pairs.</p> Signup and view all the answers

<p>Meiosis results in genetically unique cells, contributing to genetic variation in the population.</p> Signup and view all the answers

<p>The type of cell produced is determined by DNA.</p> Signup and view all the answers

<p>A nucleotide is made up of a sugar (deoxyribose), a phosphate group, and an organic base (A, C, T, or G).</p> Signup and view all the answers

<p>DNA is a very large molecule shaped as a double helix, consisting of two coiled strands.</p> Signup and view all the answers

<p>During DNA replication, the strands unwind and separate, allowing each strand to form a new partner by adding the appropriate nucleotides.</p> Signup and view all the answers

<p>The triplet code is a sequence of three bases that codes for a specific amino acid.</p> Signup and view all the answers

<p>Histones condense the DNA into chromatin, making the chromosomes visible before cell division.</p> Signup and view all the answers

<p>Sister chromatids are the replicated copies of a chromosome that join at the centromere.</p> Signup and view all the answers

<p>The short arms are called 'p' arms and the longer arms are called 'q' arms.</p> Signup and view all the answers

<p>Restriction enzymes cleave DNA at specific sequences, generating fragments with known ends necessary for DNA manipulation.</p> Signup and view all the answers

<p>Natural cloning involves asexual reproduction leading to genetically identical offspring, while artificial cloning requires techniques like nuclear transfer to create clones.</p> Signup and view all the answers

<p>Embryonic stem cells can produce all types of body cells, while skin stem cells yield only skin cells and bone marrow stem cells produce up to six types of blood cells.</p> Signup and view all the answers

<p>Human embryonic stem cells can be obtained from 10-day-old embryos.</p> Signup and view all the answers

<p>Specialized stem cells may be treated with hormones and growth factors to produce a broader range of specialized cells.</p> Signup and view all the answers

<p>Mendel observed four phenotypes: tall purple (9), tall white (3), short purple (3), and short white (1).</p> Signup and view all the answers

<p>If genes are linked on the same chromosome, they are likely to be inherited together, making separation during crossing over less probable.</p> Signup and view all the answers

<p>In incomplete dominance, both alleles are partially expressed, resulting in a blended phenotype, whereas in complete dominance, one allele completely masks the other.</p> Signup and view all the answers

<p>Roan coat color in horses and cocker spaniels illustrates co-dominance, where both alleles are independently and equally expressed.</p> Signup and view all the answers

<p>X inactivation in female mammals results in one of the two X chromosomes being randomly inactivated, observable as a Barr body.</p> Signup and view all the answers

<p>Traits on the Y chromosome are transmitted only from fathers to sons because only males have the Y chromosome.</p> Signup and view all the answers

<p>A heterozygous calico female cat will express black and orange splotches on a white coat due to co-dominance.</p> Signup and view all the answers

<p>In Mendelian genetics, each gamete carries only one allele from each gene pair, resulting in genetic variation.</p> Signup and view all the answers

<p>The possible genotypes include XB XB (female black), XB Y (male black), XR XB (female calico), and XR Y (male orange). The corresponding phenotypes are 25% black males, 25% orange males, 25% calico females, and 25% black females.</p> Signup and view all the answers

<p>Polygenic traits are traits that are controlled by two or more genes, resulting in a range of phenotypes. An example is growth rate in animals, which is influenced by multiple genes and environmental factors.</p> Signup and view all the answers

<p>Epistasis is the interaction between different genes where one gene can mask or modify the effect of another. An example is albinism, where the albino gene masks the gene responsible for coat color.</p> Signup and view all the answers

<p>Germline mutations occur in gametes and can be inherited by offspring, while somatic mutations occur in non-reproductive cells and are not passed on to offspring.</p> Signup and view all the answers

<p>Point mutations involve changes in a single nucleotide in the DNA sequence, whereas frameshift mutations involve insertions or deletions that alter the reading frame of the sequence.</p> Signup and view all the answers

<p>One method is to coat the genes onto microscopic gold particles and ‘fire’ them into the target cells.</p> Signup and view all the answers

<p>Chromosome mutations are mutations that change the structure of chromosomes, leading to alterations in both genotype and phenotype.</p> Signup and view all the answers

<p>The environment significantly influences the expression of polygenic traits, as factors like nutrition, temperature, and stress can affect the phenotypic outcome.</p> Signup and view all the answers