Genetics (Science 1.9)

Demonstrate understanding of biological ideas relating to genetic variation

Introduction to the topic and key words

Key Words List - Larn these

Welcome to the topic of genetics! Genetics is the study of heredity. Heredity is a biological process where a parent passes sure genes onto their children or offspring. Every child inherits genes from both of their biological parents and these genes in plough express specific traits. Some of these traits may be physical for example hair and middle color and skin colour etc. On the other paw some genes may also carry the risk of sure diseases and disorders that may pass on from parents to their offspring. This topic is like a new linguistic communication for most so stick at it. Learn the cardinal words, watch the videos and heed to your teachers!

Fantastic PowerPoint and resources from GZScience online here

Inheritance - interactive test

DNA - interactive Test

Nucleus is the Organelle in a cell that contains DNA.

Dna is a self-replicating molecule present in virtually all living organisms. Information technology's what the chromosomes are fabricated upwards of.

The Chromosome is a threadlike structure of nucleic acids and protein constitute in the nucleus of most living cells. They carrying genetic data in the grade of genes. Chromosomes are made upward of long lengths of Deoxyribonucleic acid.

Chromosomes Location: Contained within the nucleus

Fabricated upward of: Deoxyribonucleic acid (nucleic acids – a phosphate, sugar and base) with diverse binding proteins belongings it together

Function (what information technology does): Containing genetic information to enable an organism to manufacture all the proteins required to develop and maintain an organism when necessary.

A Gene is a short length of DNA that carries the genetic code for a item feature or prison cell activity. Unlike forms of the same cistron are called Alleles. They tin can be dominant or recessive.

A trait is a genetically determined characteristic such as center color or hair colour.

Caption of link between Dna, chromosomes and genes.

Learn Coach video

Benjamin Himme's epic video on DNA, she is a long 1!

Dna is the heredity cloth of the cell which is plant in the chromosomes in the nucleus. These are found as strands each one of these strands of Dna is called a chromosome. A gene is a segment of Deoxyribonucleic acid, found in a minor section of the chromosome. Along the Deoxyribonucleic acid, base sequences provide the lawmaking for building dissimilar proteins, which and so determine particular features. Slight differences in the sequence of the bases making upward a gene are called alleles and they cause the variations in the phenotypes. These differences pb to genetic variation between individuals.

The relationship betwixt Deoxyribonucleic acid, alleles, genes, and chromosomes

From 2013's exam.. Chromosomes are fabricated up of Dna. Dna is a large molecule that is coiled into a double helix (twisted ladder structure). It is responsible for determining the phenotype of an organism. Forth this molecule are bases. These bases pair up; A always pairs with T, and G with C.

A sequence of bases which codes for a particular trait (eg, heart colour) is called a gene.

The different versions of each gene are chosen alleles, and these show the different variations of each feature, eg brown / blue optics. Because chromosomes come up in pairs for each trait, there will be two possible alleles. These different versions of genes (alleles) occur as the Dna base sequence is dissimilar.

This combination of alleles for each trait is chosen the genotype; this can be whatever combination of two of the available alleles. The genotype determines the phenotype (the physical advent) of the organism. Whichever alleles are present may be expressed. Dominant alleles (B) will be expressed over recessive alleles (b).

Outset with these videos!

DNA from the Beginning Good introduction to Dna and genetics

DNA, or deoxyribonucleic acid, is the hereditary cloth in humans and almost all other organisms. Nearly every cell in a person's torso has the same Dna. Near DNA is located in the cell nucleus (where information technology is called nuclear DNA), only a small corporeality of Dna can also be found in the mitochondria (where it is called mitochondrial DNA or mtDNA).

The information in Deoxyribonucleic acid is stored equally a code fabricated up of four chemical bases: adenine (A), guanine (G), cytosine (C), and thymine (T). Homo Dna consists of about 3 billion bases, and more than 99 pct of those bases are the same in all people. The guild, or sequence, of these bases determines the data bachelor for building and maintaining an organism, similar to the style in which letters of the alphabet appear in a certain guild to form words and sentences.

Dna bases pair up with each other, A with T and C with G, to class units called base of operations pairs. Each base of operations is also attached to a sugar molecule and a phosphate molecule. Together, a base, sugar, and phosphate are chosen a nucleotide. Nucleotides are arranged in two long strands that form a screw called a double helix. The structure of the double helix is somewhat similar a ladder, with the base pairs forming the ladder'south rungs and the sugar and phosphate molecules forming the vertical sidepieces of the ladder.

Build a Dna molecule, click here!

The shape of Deoxyribonucleic acid at the molecular level is thought to expect like a gently twisting ladder. Each of the rungs on the ladder represents a chemical bond between the chemicals that make up the Dna molecule. These chemicals are called nucleotides and include: (click on image to brand bigger)

DNA is made from Deoxyribonucleic Acid. DNA is called a polymer because it is made up of many repeating units called nucleotides.

Play the post-obit blitheness

DNA strands are loose within the nucleus of a cell. Just prior to prison cell partitioning the Dna folds up around proteins chosen histones into tight coils, then into structured chromosomes. The human cell has 46 chromosomes arranged into 23 pairs of chromosomes. Each chromosome in a pair has the aforementioned genes, chosen homologous pairs – except the sexual practice chromosome pair – although in that location may exist variation between the genes of each pair, as one comes from the begetter and one comes from the female parent.

Chromosomes are made up of long lengths of DNA bundled in a twisted ladder.

The base of operations pairing rules hateful that guanine (G) always bonds to cytosine (C), and thymine (T) ever bonds to adenine (A).

Complete the following interactive workshop http://learn.genetics.utah.edu/content/molecules/cistron/

A gene is a section of DNA that carries the genetic code for a particular characteristic. An allele is an alternative form of a cistron. They tin can exist dominant or recessive.

During fertilisation a person gets two dissimilar alleles for the same gene because i allele is inherited from your mother, the other comes from your father.

A keen video that covers this in more detail than is required a L1. Y'all need to know where information technology happens, why it happens and the basics steps that are beneath.

Stage 1.

The original Dna strand unwinds every bit the bonds between the bases break.

Stage 2.

New nucleotides are brought in. They bail with the bases on the original Dna strand according to the base-pairing rules.

Stage 3.

In one case the new nucleotides have bonded, the Deoxyribonucleic acid molecule begins to coil back up into a double helix. At the stop of the process, two new strands of DNA are produced. Both are verbal copies of the original strand.

Chromosomes come up in pairs. One pair is the sexual practice chromosomes – Xx in females and XY in males. A complete set of chromosomes of an organism placed into pairs of matching chromosomes is called a karyotype. The human karyotype consists of 23 pairs of chromosomes

The way in which genotype determines phenotype

From Science learning hub: come across the whole folio here

Genotype is the genetic make-up of an individual organism. Your genotype functions every bit a fix of instructions for the growth and development of your body. The discussion 'genotype' is usually used when talking near the genetics of a particular trait (like eye colour).

Phenotype is the observable physical or biochemical characteristics of an private organism, determined past both genetic make-up and ecology influences, for example, height, weight and peel colour.

Video here

A codon is a group of iii bases that code for an specific amino acrid.Deoxyribonucleic acid contains the instructions for linking amino acids. These amino acids bring together together to make proteins. Proteins are important considering they are the building blocks of our body and conduct out many important functions within the body. The base sequence of DNA can be broken downward into codons (three-alphabetic character sequences). 1 codon codes for one amino acid.

The fashion chromosomes exist every bit pairs so that individuals inherit two copies of each cistron

Homologous pairs are chromosomes that have the same genes.

Biological concepts and processes relating to variation in phenotype will be selected from:

The significance of an allele as an alternative version of a gene

Animation - some genes are dominant!

An allele is an alternative form of a factor (one member of a pair) that is located at a specific position on a specific chromosome.

Organisms have ii alleles for each trait. When the alleles of a pair are heterozygous, one is ascendant and the other is recessive. The ascendant allele is expressed and the recessive allele is masked.

The cistron for seed shape in pea plants exists in ii forms, one form or allele for round seed shape (R) and the other for wrinkled seed shape (r).

Organisms accept two alleles for each trait. When the alleles of a pair are heterozygous, i is dominant and the other is recessive. The dominant allele is expressed and the recessive allele is masked. Using the previous example, circular seed shape (R) is dominant and wrinkled seed shape (r) is recessive. Round: (RR) or (Rr), Wrinkled: (rr).

The part of mutations in forming new alleles

A mutation is a modify in the base sequence of DNA acquired by a mutagen. A mutagen is an agent, such as a chemical substance, UV light or radiation, that causes genetic mutation.

Mutation is a permanent / random changes in the Dna/ genetic material. Mutation must occur in gamete-producing cells to enter the gene pool of the population

A mutation is a permanent (unrepaired) change in an organisms DNA.

They innovate new alleles into a population. Almost mutations are harmful.

Mutations are caused by mutagens.

Beneficial ones tend to occur more often in organisms with short generation times.

Many may be silent – not observed – and may just be selected for or confronting at a later date.

Neutral mutations make no change at all.

Beneficial mutation = A mutation that gives an organism a survival advantage.

Harmful mutation = A mutation that effects the survival of the organism.

Silent mutation = a mutation which has no observable effect on the organism.

link

Wiki commodity link

Mutation animation link

Genes Chromosomes and Mutations

The office of meiosis in generating gametes

(yous are not required to provide the names of the stages of meiosis)

Did yous know?

Sex cells have 1 set of chromosomes; body cells have ii. Click here to work through an animation

Excellent animation Click here

Online simulator for Mitosis and Meiosis Click here

Meiosis is a type of cell division that occurs in the testes (males) and ovaries (females). Information technology produces four new cells (gametes) that are genetically different to each other, and to the parent prison cell. They contain half the number of chromosomes that are in the parent cell.Meiosis leads to genetic variation via 2 processes. When homologous pairs of chromosomes line upwards during meiosis, they do so randomly. This means it is completely random which combination of alleles end upward in a particular gamete. This process is chosen independent assortment.The 2nd way meiosis leads to genetic variation is via a process called crossing over. This occurs when homologous pairs of chromosomes line up at the cell equator and swap sections of genetic material, and therefore alleles. Considering of crossing over, each gamete volition contain different combinations of alleles.

Mitosis explained (in more detail than you need at L1)

The significance of sexual reproduction

(in producing a new mix of alleles)

With sexual reproduction two individuals contribute genetic material with traits more often than not being determined by the two alleles for each gene. The procedure of meiosis which creates the gametes and recombination leads to an individual with a genetic make-up that differs from both parents. Over time that process allows the movements of alleles from one population to the next.

• Gametes are sex cells (sperm and egg) which are formed in the testes and ovaries. During gamete formation (meiosis), the homologous chromosomes are halved and the gamete volition inherit 1 of each pair of chromosomes. Which chromosome is passed on is random due to the process of independent assortment.

• During fecundation, the gametes combine and the resulting offspring volition have two alleles – they may inherit two alleles the same, homozygous, and prove that feature or they may inherit one of each allele, heterozygous in which example they volition evidence the dominant allele in their phenotype. Genetic variation: multifariousness within a population, eg different alleles possible for each cistron. The advantage of variation to a population is that it may see some individuals survive if environment changes, in this case if drought occurs. Considering of variation, non all individuals will be wiped out. Those with favourable alleles / traits / phenotypes volition survive and exist able to pass on genetic material to offspring and therefore survival of the species occurs.

• Possible disadvantages: need two parents that are able to reproduce, if conditions are stable could introduce variation, which may exist counterproductive.

The patterns of inheritance involving unproblematic monohybrid inheritance showing complete authority

If you work through the student part of this animation series y'all volition know everything y'all need to on monohybrid crosses.

another tool.

A powerpoint covering the basics

Animation practice of monohybrid crosses

Sex conclusion, possible genotypes, and phenotype ratios.

A good intro blitheness

humans and many other animal species, sex activity is determined by specific chromosomes. How did researchers discover these and then-called sex activity chromosomes? The path from the initial discovery of sexual activity chromosomes in 1891 to an understanding of their true function was paved by the diligent efforts of multiple scientists over the course of many years. Equally often happens during a lengthy course of discovery, scientists observed and described sexual activity chromosomes long before they knew their office.

In humans, females inherit an 10 chromosome from each parent, whereas males always inherit their X chromosome from their mother and their Y chromosome from their father. Consequently, all of the somatic cells in human females comprise ii X chromosomes, and all of the somatic cells in man males incorporate one X and one Y chromosome (Figure iii). The same is truthful of all other placental mammals — males produce 10 and Y gametes, and females produce only X gametes (Figure four). In this system, referred to as the Twenty-XY system, maleness is adamant by sperm cells that carry the Y chromosome.

A very interesting animation of how the chromosomes change phenotype betwixt the sexes.

The following punnet foursquare is commonly required to exist completed in a sex determination question, observe you have a 50% chance of being male or female.

A pedigree chart is a diagram that shows the occurrence and appearance or phenotypes of a particular gene or organism and its ancestors from one generation to the next. This is used most commonly humans, show dogs, and race horses and NCEA usually asks you to identify genotype from the blueprint shown in the chart.

Biological concepts and processes relating to variation in phenotypes as adaptive features will exist selected from

Inheritable and non-inheritable variation

An splendid PowerPoint on variation

Continuous Variation

  • Many phenotypes prove continuous variation – there are many intermediate forms and the distribution of the phenotypes in a population is a bell bend.
  • Traits that show continuous variation include: tiptop and weight in humans, milk production in cows and the size of flowers.
  • Continuous traits are usually polygenic, with alleles of many unlike genes contributing to produce the last phenotype.
  • This results in considerable phenotypic variation, and further variation may likewise occur due to interactions with the environment.

Discrete Variation

  • The phenotypes nosotros accept consider so far accept been due to two segregating alleles of unmarried genes.
  • This ways that alternative phenotypes are clearly dissimilar.
  • This variation or departure betwixt phenotypes is known as discontinuous variation.

•Variation in phenotype in populations is influenced by the following factors:

–One gene can accept many alleles

–Meiosis involves independent assortment and genetic recombination of alleles

–Dominance may not exist complete

–Several genes can bear on the one trait

–One gene tin can determine more than one trait

–The expression of genes can be affected past other genes and by the environment

Differing rates of survival by various members of a group may depend on their phenotype

A genetically "healthy" population is defined as having a large amount of genetic variability. The information for each of an organism's characteristics is carried on a gene, but a gene can have unlike forms. These are known every bit alleles, and a large range of alleles leads to a wide diversity of genetic "options" or genetic "possibilities".

With a large corporeality of genetic variation, natural selection is able to operate by altering the frequency of particular alleles in response to environmental conditions. Alleles providing a survival benefit to a population increment in frequency while those producing a selective disadvantage decrease or are lost altogether from the population.

The impact of natural selection acting on populations tin can be observed through phenotypic (concrete) traits.

What is natural option?

natural selection A expert starter activity

Evolution lab. A good interactive activity

The importance of variation within populations

(population and species survival) in a changing

The advantages and disadvantages of sexual reproduction.

Sexual Reproduction is reproduction involving merely two parents. The offspring are different to the parent and to each other.

Advantages

• Allows for genetic variation due to the joining of 2 unlike individuals.

• Population has a greater hazard of surviving if the surround changes.

Disadvantages

• Less population growth.

• Relatively tiresome procedure.

• Requires more than energy use.