Genetics: Homozygous and Heterozygous Genotypes

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Questions and Answers

What does an organism homozygous at a given locus possess?

Two copies of different alleles

Multiple copies of various alleles

Two copies of the same allele (correct)

One allele of a gene

What is the term for the trait that is expressed in a heterozygous state?

Dominant trait (correct)

Heterozygous trait

Homozygous trait

Recessive trait

What is the primary purpose of using a vector in genetic engineering?

To produce a genetically modified organism

To transfer a gene into a host organism (correct)

To alter the DNA of an organism

To create a transgenic organism

What is the term for DNA that has sequences from multiple species?

Recombinant DNA Signup and view all the answers

What is a concern surrounding genetic engineering?

Environmental concerns Signup and view all the answers

What is the primary function of plasmids in genetic engineering?

To act as cloning vectors Signup and view all the answers

What is the characteristic of an animal with radial symmetry?

Its halves look the same no matter how the animal is split in relation to the center Signup and view all the answers

Which of the following is NOT a characteristic of animal body plans?

Cell wall Signup and view all the answers

What is the term for the process of plasmid integration into a host bacterium?

Episomes Signup and view all the answers

Which of the following groups of animals does NOT have a vertebral column?

Invertebrates Signup and view all the answers

What is a characteristic feature of flatworms?

Only one opening as part of their digestive system Signup and view all the answers

What is another term for segmented worms?

Annelids Signup and view all the answers

What is an example of a parasitic worm that can infect humans?

Hookworm Signup and view all the answers

What do parasitic worms take from their host?

Nutrients Signup and view all the answers

What is the shape of roundworms?

Rounded Signup and view all the answers

What is the main distinguishing feature of Phylum Porifera?

They are sessile filter feeders Signup and view all the answers

What do animals in Phylum Cnidaria have in common?

They possess specialized stinging cells Signup and view all the answers

Which phylum includes microscopic predators?

Phylum Rotifera Signup and view all the answers

What feature distinguishes Phylum Nematomorpha from other phyla?

They are often parasites in insects Signup and view all the answers

How do the animals in Phylum Echinodermata protect themselves?

By having a hard exoskeleton Signup and view all the answers

Study Notes

Genotype and Gene Expression

An organism homozygous at a given locus has two copies of the same allele (e.g., 'BB' and 'bb' are both homozygous genotypes)
An organism heterozygous at a given locus has two different alleles (e.g., 'Bb' is a heterozygous genotype)
A dominant trait is expressed in a heterozygous state
A recessive trait is not expressed in a heterozygous state

Genetic Engineering

Genetic engineering involves altering an organism's genome using a vector (e.g., plasmid, bacterial chromosome, or virus) to transfer a gene into a host organism
Plasmids are naturally found in bacteria and are good vectors for transferring DNA into bacteria
Recombinant DNA is DNA that has sequences from multiple species
Genetic engineering can produce transgenic organisms (organisms with DNA from different species) and genetically modified organisms (organisms with altered DNA, not necessarily from another species)
Uses of genetic engineering include agriculture, medicine, research, and commercial applications
Genetic engineering is controversial due to ethical and environmental concerns

Plasmids

A plasmid is a small circular DNA molecule separate from the chromosome of a host cell
Plasmids replicate independently inside a host cell and can be used as cloning vectors
Construction of plasmids involves using restriction enzymes at restriction sites
Plasmids have an origin of replication, a selectable marker, and a region for inserting foreign DNA
Plasmids can be used for gene therapy, creating disease models, protein production, and cloning
Examples of plasmids include the virulence plasmid in Escherichia coli and Salmonella enterica

Animal Body Plans

Animal body plans help with the study, classification, and differentiation of animals in evolutionary and developmental biology
Features that distinguish animal body plans include body symmetry, body cavities, tissues, mouths, and the locations of structures
Body symmetry can be radial (animal's halves look the same no matter how it's split) or bilateral (animal's halves mirror each other)
Examples of body plans include coelom, pseudocoelom, and the development of mouth and anus

Kingdom Animalia

All animals in Kingdom Animalia are multicellular heterotrophs without a cell wall
Animals can be classified as vertebrates (with a backbone) or invertebrates (without a backbone)
Vertebrates include fish, amphibians, reptiles, birds, and mammals
Invertebrates are divided into over 30 phyla and 1.3 million species, with unique features such as digestive chambers instead of complete digestive tracts

Types of Worms

There are three main types of worms: flatworms, roundworms, and segmented worms
Flatworms are typically flat in appearance and have one opening in their digestive system
Roundworms are more rounded in shape and have two openings in their digestive system
Segmented worms have a segmented body with organ structures in each segment
Examples of worms include tapeworms, hookworms, and earthworms
Some worms are parasitic and can infect other organisms, taking nutrients and negatively impacting the host

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Description

Learn about the different genotypes in genetics, including homozygous and heterozygous genotypes. Understand the concepts of dominant and recessive traits in organisms.