FreeNotes
Genes and Alleles: Genes and alleles are fundamental concepts in genetics that explain how traits are inherited and expressed in living organisms. 1. What are Genes? A gene is a segment of DNA (or RNA, in some cases) that carries the instructions for making proteins or RNA molecules that influence the characteristics (traits) of an … Read more
Chromatin is a complex of DNA and proteins that makes up the chromosomes in the nucleus of a cell. It plays a key role in packaging the DNA into a compact form so that it can fit inside the cell nucleus, and also regulates gene expression and DNA replication. Here’s the composition of chromatin material … Read more
Genes control the inheritance of characteristics (or traits) through a process known as genetic inheritance, which is governed by the transfer of genetic material (DNA) from parents to offspring. Here’s how genes control this inheritance: Genes and Alleles: Genes are segments of DNA that carry the instructions for making proteins, which influence the traits of … Read more
Heterozygous: Aa, Bb Homozygous: AA, ss Same phenotype: BB and Bb (if B is dominant) Related Questions: Write the differences between: Name sources of variation. Give examples of artificial selection. What kind of gametes would be produced by organisms having the following genotypes? Two white sheep produce a black offspring. What must the parents’ genotype … Read more
a. Which variety was more common when there was more air pollution? Give a reason as well. Dark-colored moths were more common due to industrial melanism, as they blended better with polluted, dark tree bark, avoiding predation. b. Which variety is more common in England nowadays? Give a reason as well. Light-colored moths are now … Read more
The parents must be heterozygous (Bb). The probability of a black offspring (bb) is 25%. Related Questions: Write the differences between: Name sources of variation. Give examples of artificial selection. What kind of gametes would be produced by organisms having the following genotypes? Name the structure through which the exchange of gases can take place … Read more
AaBB: AB, aB aaBB: aB, aB AAbb: Ab, Ab Related Questions: Write the differences between: Name sources of variation. Give examples of artificial selection. Two white sheep produce a black offspring. What must the parents’ genotype for colour be? What is the probability that the next offspring will be black? The diagram shows two … Read more
Breeding of high-yield crops Selective breeding of dairy cows for more milk production Breeding of dogs for specific traits Related Questions: Write the differences between: Name sources of variation. Name the structure through which the exchange of gases can take place in plants. Name the ways through which a plant can obtain oxygen. Why should … Read more
Genetic recombination Mutation Independent assortment of chromosomes Crossing over during meiosis Related Questions: Write the differences between: Name the structure through which the exchange of gases can take place in plants. Name the ways through which a plant can obtain oxygen. Why should one not sleep under a tree at night? Why would very wet … Read more
Antigen and antibodies: Antigens are foreign substances that trigger an immune response, while antibodies are proteins produced by the immune system to neutralize antigens. Variation and evolution: Variation refers to differences among individuals within a species, whereas evolution is the gradual change in species over generations due to variation and natural selection. Discontinuous and continuous … Read more