Test 3 (cap 16 and 18) Flashcards Preview

AP Biology > Test 3 (cap 16 and 18) > Flashcards

Flashcards in Test 3 (cap 16 and 18) Deck (10):
1

Know what HOX genes are and what they are responsible for. If there is a mutation in the HOX gene, what might happen?

Hox genes directly controls the identity of body parts
Controls the genes for development and production of body formation and code for transcription factors
Such as pattern formation
Pattern formation determines where body parts will end up
EX: fly larvae
Associated with development
If there is a mutation a species may have more than one head or no head at all. It will code for the wrong thing causes the growing specie to be born with a mutation/abnormality

2

Know what enhancers and repressors are and what they do to genes.

An enhancer is a segment of eukaryotic DNA containing multiple control elements, usually located far from the gene whose transcription it regulates
Segment of eukaryotic DNA that contains ,multiple control elements that are upstream from the gene it regulates (DIAGRAM ON PG 301)
Forms hairpin
A repressor is a protein that inhibits gene transcription.
Repressor is a protien macromolecule that inhibits gene transcription
In prokaryotes, repressors bind to the DNA/operator site in or near the promoter
In eukaryotes, repressors may bind to control elements within enhancers, to activators, or to other proteins in a way that blocks activators from binding to DNA

3

What are protooncogenes and oncogenes? What do they do?

A protooncogene is a normal cellular gene that has a potential to become an oncogene (used in normal cell growth)
An oncogene is a gene found in viral or cellular genomes that is involved in triggering molecular events that can lead to cancer
Codes for the things that triggers and enhances molecular events and division that cause cancer

4

Know the difference between adult and embryonic stem cells and their abilities to become differentiated cells.

Stem cells are a relatively unspecialized cell that can both reproduce itself indefinitely and, under appropriate conditions, differentiate into specialized cells of one or more types (have total ability)
Embryonic stem cells reproduce indefinitely and they can be made to differentiate into a variety of specialized cells
Adult stem cells are not able to to give rise to all cell types in the organism, though they can generate multiple types. (have limited ability)
Can produce: red blood cells, bone cells, fat cells, blood vessel linings
Found in red bone marrow

5

Know what the term totipotent means.

describes a cell that can give rise to all parts of the embryo and adult, as well as extraembryonic membranes in species that have them
It can become any type of cells

6

Know what transposons are, how they move and what they do

A transposable element (DNA segment) that moves within a genome by means of a DNA intermediate (copying itself, copying DNA for DNA and pastes it in another area of the genome)
Help determine differences in organisms, species, produce RNAs in RNA synthesis, help gene expression-make up about 25-50% of our genome

7

Know what retrotransposons are, how they move and what they do

A transposable element that moves within a genome by means of an RNA intermediate, a transcript of the retrotransposon DNA.
They always leave a copy at the original site during transposition, since they are initially transcribed into an RNA intermediate
DNA is transcribed into mRNA using reverse transcriptase, gets transcribed back into DNA form to then be pasted in the genome
Help determine differences in organisms, species, produce RNAs in RNA synthesis, help gene expression-make up about 25-50% of our genome
EX: alu gene

8

Know what homeotic genes are. What do they do?

Any of the master regulatory genes that control placement and spatial organization of body parts in animals, plants, and fungi by controlling the development fate of groups of cells

9

How many genes are in the human genome?

20-25,000

10

What are multigene families? What would be an example of one?

A collection of genes with similar or identical sequences, presumably of common origin
EX: The genes for the three largest rRNA molecules
EX: Alpha and Beta globin forms