Inheritance Spec Points PDF

## Inheritance ### Students should: - understand that the genome is the entire DNA of an organism and that a gene is a section of a molecule of DNA that codes for a specific protein - understand that the nucleus of a cell contains chromosomes on which genes are located - describe a DNA molecule as t...

## Inheritance ### Students should: - understand that the genome is the entire DNA of an organism and that a gene is a section of a molecule of DNA that codes for a specific protein - understand that the nucleus of a cell contains chromosomes on which genes are located - describe a DNA molecule as two strands coiled to form a double helix, the strands being linked by a series of paired bases: adenine (A) with thymine (T), and cytosine (C) with guanine (G) - understand that an RNA molecule is single stranded and contains uracil (U) instead of thymine (T) - describe the stages of protein synthesis including transcription and translation, including the role of mRNA, ribosomes, tRNA, codons and anticodons - understand how genes exist in alternative forms called alleles which give rise to differences in inherited characteristics - understand the meaning of the terms: dominant, recessive, homozygous, heterozygous, phenotype, and genotype - understand the meaning of the term codominance - understand that most phenotypic features are the result of polygenic inheritance rather than single genes - describe patterns of monohybrid inheritance using a genetic diagram - understand how to interpret family pedigrees - predict probabilities of outcomes from monohybrid crosses - understand how the sex of a person is controlled by one pair of chromosomes, XX in a female and XY in a male - describe the determination of the sex of offspring at fertilisation, using a genetic diagram - understand how division of a diploid cell by mitosis produces two cells that contain identical sets of chromosomes - understand that mitosis occurs during growth, repair, cloning and asexual reproduction - understand how division of a cell by meiosis produces four cells, each with half the number of chromosomes, and that this results in the formation of genetically different haploid gametes - understand how random fertilisation produces genetic variation of offspring - know that in human cells the diploid number of chromosomes is 46 and the haploid number is 23 - understand that variation within a species can be genetic, environmental, or a combination of both - understand that mutation is a rare, random change in genetic material that can be inherited - understand how a change in DNA can affect the phenotype by altering the sequence of amino acids in a protein - understand how most genetic mutations have no effect on the phenotype, some have a small effect and rarely do they have a significant effect - understand that the incidence of mutations can be increased by exposure to ionising radiation (for example, gamma rays, x-rays and ultraviolet rays) and some chemical mutagens (for example, chemicals in tobacco) - explain Darwin's theory of evolution by natural selection - understand how resistance to antibiotics can increase in bacterial populations, and appreciate how such an increase can lead to infections being difficult to control