biology Flashcards
(62 cards)
What does DNA stand for?
Deoxyribonucleic acid
DNA stands for Deoxyribonucleic acid.
Where is DNA found in the body?
In the nucleus of every cell in the body except red blood cells
DNA is found in the nucleus of every cell in the body except red blood cells.
What does DNA carry?
Building instructions for proteins
DNA carries the building instructions for proteins.
What does DNA have the same structure as?
Same in every living thing on Earth
DNA has the same structure in every living thing on Earth.
What is DNA made up of?
Repetitive nucleotides
DNA is made up of lots of repetitive nucleotides.
What is a nucleotide made up of?
Phosphate group, deoxyribose sugar, one of four nitrogenous bases
One nucleotide is made up of a phosphate group, a deoxyribose sugar, and one of four nitrogenous bases.
What are the four nitrogenous bases in DNA?
Adenine, thymine, guanine, cytosine
The nitrogenous bases in DNA are labelled A, T, G, and C, which stand for adenine, thymine, guanine, and cytosine.
What is the complementary base pairing rule in DNA?
A always bonds with T, C always bonds with G
In DNA, A always bonds with T and C always bonds with G - this is called the complementary base pairing rule.
What does DNA look and described as
A twisted rope ladder; this is called the double helix.
Think of DNA as a twisted rope ladder; this is called the double helix.
What are chromosomes?
thread like structure made of DNA and proteins
found in the nucleus of a cell
## Footnote
When the cell is about to divide though it all collects together and compresses into structures called chromosomes.
How many chromosomes do humans have?
46: 23 from each parent, 23 pairs.
Humans have 46 chromosomes: 23 from each parent, so 23 pairs.
What determines biological gender?
The presence or absence of the Y chromosome.
The presence or absence of the Y chromosome determines your biological gender.
of the 23 pairs of chromosomes, what is 1 pair called
sex chromosomes
What is a gene and what is it made of?
the basic unit of heredity passed from parent to child, made up of DNA
## Footnote
A gene is a sequence of bases that carry the building instructions for a single
Are the sequences of bases for each gene the same?
No, the sequence of bases for each gene is different.
This diversity in gene sequences is what gives rise to the variety of proteins in living organisms.
Can the number of bases in a gene vary?
Yes, the number of bases in a gene can also vary.
This variation in the length of genes can lead to different protein structures and functions.
What is a species?
group of organisms that can reproduce with each other to produce fertile offspring.
Example: Lions, tigers, and leopards are all different species of big cats.
What is a hybrid?
offspring of two individuals who are not the same species.
the offspring are infertile.
Example: A liger is a hybrid offspring of a male lion and a female tiger.
Taxonomy
the science of classifying living things
The science of classifying living things is called taxonomy.
What are the 8 levels of Linnaean classification?
Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species
He created 7 ‘levels’ of classification (which has now expanded to 8): domain, kingdom, phylum, class, order, family, genus, species.
What can be used to remember the 8 levels of Linnaean classification?
Mnemonic: dumb kids playing cricket on freeways get squashed.
This can be remembered with the mnemonic dumb kids playing cricket on freeways get squashed.
What is the ‘least alike’ level in Linnaean classification?
Domain
In this system, domain is the ‘least alike’ level.
What is the ‘most alike’ level in Linnaean classification?
Species
In this system, species is the ‘most alike’ level.
What is Linnaean classification system based on
based on similarities in obvious physical traits
