biology eoy

How many pairs of chromosomes are there in a normal human cell?

Base Pairs:Cytosine,Guanine Thymine,Adenine

What does DNA look like?

Genotype-the combination of [blank_start]alleles[blank_end] an organism has for a gene.

[blank_start]Phenotype[blank_end]-what the organism looks like.

What is diploid?

[blank_start]Chromosomes[blank_end] contain genes-the instructions that tell cells what we [blank_start]look[blank_end] like. There are 23 pairs of chromosomes in a [blank_start]normal[blank_end] human cell. [blank_start]Genes[blank_end] are the units that make up chromosomes. They are responsible for [blank_start]inheritance[blank_end] of specific characteristics. [blank_start]Alleles[blank_end] are the different versions of genes.

What does the 23rd pair of chromosomes determine?

A [blank_start]punnet[blank_end] square only predict how much of a chance there is for the child to have a certain characteristic.

Characteristics are physical features of an organism that sometimes can be seen and other times they can't.

[blank_start]Variation[blank_end] is the difference in characteristics in a population.

Variation can be caused by the [blank_start]environment[blank_end] or our [blank_start]genes.[blank_end]

Inherited characteristics are:

What characteristics can be inherited and environmental?

discontinuous variation-A characteristic that could be measured in a range of different values.

Selective [blank_start]breeding[blank_end] is the process used by humans to breed new [blank_start]organisms[blank_end] with desirable [blank_start]characteristics[blank_end].

To selectively breed is to choose a [blank_start]desirable[blank_end] characteristic,choose parents with these characteristics,select the best offspring with the desirable characteristic to breed in the next generation and [blank_start]repeat[blank_end] the process over generations.

Examples of selective breeding:

problems caused by selective breeding:

To selectively breed a plant, the [blank_start]farmer[blank_end] decides the characteristic the plant should have,finds few plants withe the characteristics, cover so of the flowers of the selected plants, use a cotton bud to collect [blank_start]pollent[blank_end] from other selected plants,uncover the stigmas from covered plants and brush the pollen onto them,[blank_start]fertilisation[blank_end] occurs,collect and plant the seeds,wait for seeds to develop, seeds will grow into plants,select [blank_start]induvidual[blank_end] plants with the desired characteristics and use them to repeat the process over generations.

Why might people want to selectively breed plants?

examples of selective breeding in plants

What is a gene bank?

It is important to preserve hereditery material of animals and plants to [blank_start]preserve[blank_end] endangered animals and plants so they don't become extinct

Cloning is the production of [blank_start]genetically identical organisms[blank_end].

why might farmers clone their animals?

the process of cloning animals- first, enucleate the [blank_start]unfertilised[blank_end] ovum from animal 1 and keep the [blank_start]ovum[blank_end] remove the nucleus from a [blank_start]somatic[blank_end] cell in animal 2 and keep the nucleus put the nucleus from sheep two into the ovum from sheep 1 apply a mild electric current to encourage the nucleus to be taken up by the ovum the cell divides by [blank_start]mitosis[blank_end] after 6 days, the embryo is put into the [blank_start]uterus[blank_end] of the surrogate mother the surrogate mother will then give birth to a cloned baby.

Advantages of cloning:

Disadvantages of cloning: