DNA / Genetics Study Guide

Created by bpaul 

Upgrade to
remove ads

DNA Structure

DNA consists of two long chains of nucleotides twisted into a double helix and joined by hydrogen bonds between the complementary bases adenine and thymine or cytosine and guanine

DNA Function

Blue print containing all the instructions needed for building the whole body. Contained in the nucleus of all cells

Double Helix

Steps of Protein Synthesis

1. RNA "unzips" the DNA double helix. 2. RNA nucleotides are put together to make mRNA. 3. mRNA leaves the nucleus to go to a ribosome in the cytoplasm 4. the ribosome matches up tRNA anticodons with the mRNA codons 5. each tRNA carries one amino acid 6. finally the amino acids are joined together to make a protein.

DNA vs RNA

RNA contains ribose instead of deoxyribose, RNA contains uracil instead of thymine like DNA, RNA is single-stranded rather than double-stranded like DNA, RNA is smaller than DNA, RNA can leave the nucleus but DNA cannot.

DNA Replication

Process in which chromosomal DNA is copied before mitosis or meiosis. It is important for reproduction and growth.

Meiosis

Cell division that produces reproductive cells in sexually reproducing organisms. This is important in the transfer of alleles for traits during reproduction.

Human Chromosomes

Humans have 46 chromosomes in every cell (23 pairs)

Gregor Mendel

Austrian monk and botanist whose experiments in breeding garden peas led to his eventual recognition as founder of the science of genetics (1822-1884)

Mendel's F1 Generation

The second generation in his experiments. The offspring of the first generation. All were homozygous, but the phenotype was the dominant trait and all contained the recessive trait as well.

Mendel's F2 Generation

Mendel self-pollinated the F1 generation. Their offspring (from F1) showed all possible combinations of the 2 characteristics. Some had green full pods, for example, and some had yellow constricted pods. These combinations were not present in the P or F1 generation.

Genotype vs Phenotype

genetic makeup of an organism vs external appearance of an organism that is determined by the individual's genotype. Ex. Genpype = Tt, Phenotype = Tall plant

Eye Color

Two brown eyed parents can have a blue eyed child. If brown is dominant over blue and both parents are heterozygous there is a 25% chance of the child having blue eyes.

Incomplete Dominance vs Codominance

ID: a new phenotype is expressed (different from parents) CoD: both parental phenotypes are expressed from the parents.

Test Cross

the crossing of an individual of unknown genotype with a homozygous recessive individual to determine the unknown genotype.

Fruit Fly Life Cycle

1. egg (too small to see) 2. larva (crawls through food and grows) 3. Pupa (larva crawls up to a high point and forms a cocoon type shell) 4. Adult (emerges from pupa)

Fruit fly Genders

Male: smaller, sex comb on front legs, bristles, rounded abdomen. Female: larger, lighter abdomen, no bristles, no sex comb, pointed abdomen.

Fruit fly Crosses

We looked at the trait of wings in fruit flies. Flies without wings are apterous and flies with wings are wild. wild is dominant over apterous. We crossed heterozygous flies which had the genotype Ww and therefore the possibility of having offspring of both types. In this cross we found that approximately 25% of the offspring were apterous, which corresponds with Mendel's crosses of pea plants and our Punnet square predictions.

Gamete

Sex cell. Contains DNA for half of the genotype for a certain trait. Ex. sperm/egg

Zygote

A fertilized egg. Result of gametes joining.

Diploid

A cell or organism having two sets of chromosomes or twice the haploid number

Haploid

Of a cell or organism having a single set of chromosomes. Result of meiosis.

Multiple Alleles

Three or more alleles exist for a particular trait

Blood Type Inheritance

Multiple alleles- Blood types' possible alleles are IA, IB, and i so it has more than three possible alleles for every genotype.
Codominance- It's possible to have blood type "AB" which means that one would produce both A and B bloodcells equally

Flickr Creative Commons Images

Some images used in this set are licensed under the Creative Commons through Flickr.com. Click to see the original works with their full license.

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions above and try again

Example:

Reload the page to try again!

Reload

Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

NEW! Voice Recording

Create Set