Dna And Genes Flashcards Preview

Biology n > Dna And Genes > Flashcards

Flashcards in Dna And Genes Deck (28):

Give one reason as to why it might be important for a scientist to be able to remove DNA from an organism?

So that they are able to see what makes up the organism, how it's genetics work or to see if there are any gene mutations


What does DNA stand for?

Deoxyribo Nucleic Acid


Where does DNA control?

Our characteristics and features, what gender we are, how we look, if we have any allergies or diseases that are genetic.


What is DNA?

For most living things deoxyribo nucleic acid is the molecule that determines their characteristics or traits and also contributes to the diversity of living things


What is DNA made up of?

DNA has the same structure in all organisms, it is made up of nucleotides (smaller molecules)


What are the three parts of nucleotides?

Phosphate group, deoxyribose sugar and one of four nitrogen rich bases


How are nucleotides organised?

They are organised to make DNA a double helix. The uprights (sides) of the ladder are made of alternating phosphate and sugar groups.


What are the four nitrogen rich bases?

Adenine [A], Thymine [T], Guanine [G] and Cytosine [C]


What is complementary base pairing?

The four bases can only pair up in ONE way =complementary base pairing, A+T and G+C


Who are Watson and Crick

In 1953 James Watson and Francis Crick successfully described the DNA structure. Today the model used to describe DNA is know as the Watson-Crick model


Who is Rosalind Franklin?

A British chemist who was part of the discovery of the structure of DNA


Who is Maurice Wilkins?

A biophysicist known for his contributions to the discovery of DNAs molecular structure


What are chromosomes?

Long, thing, threadlike structures found in the nuclei of all cells in the human body that contain a nucleus


What are chromosomes made up of?

The are made up of one very long DNA molecule wrapped in proteins


How many chromosomes do most humans have? What are the sex chromosomes?

Most humans have around 46 chromosomes. Two of them are sex chromosomes called X and Y females have XX and males have XY


What are the 44 chromosomes? (Excluding the sex chromosomes)

The other chromosomes are autosomes and they control non sex characteristics and they are grouped into 22 pairs. The chromosomes in each pair a homologous.


The similarities of homologous chromosomes?

They are the same length have this same position centromere and have genes for particular characteristics at the same location along their length.


What is a centromere?

The point on a chromosome were two chromatids are joined together


What is a karyotype?

A karyotype shows the pairs of chromosomes for a human cell


What are genes?

Genes are sections of DNA arranged along the DNA the order and number of bases will vary between genes


Do you bases and codes control?

Bases or codes contain instructions for particular characteristics for that person.


What's the difference between chromosomes and genes?

Chromosomes are a long DNA molecule wrapped in proteins and genes are sections of DNA arranged along the chromosome.


What are the characteristics of DNA that create genetic code?

The characteristics of DNA that create genetic code of the sequence of the four bases and the variation of them.


What determines whether the bases from complimentary base pairs?

The hydrogen bonds determine whether the bases before and complimentary base pairs A+T have two and C+G have three.


What do sex chromosomes control?

Six chromosomes also control sex characteristics primary characteristics such as gender and secondary characteristics such as voice.


Where do your chromosomes come from?

Half of your chromosomes come from your father and half come from your mother.


How many chromosomes do all cells in our bodies have?

All cells in your body have 46 chromosomes except the sex cells which have 23.


How many genes are there in a chromosome?

The number of genes in a chromosome ranges from 200 to 2000.